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云计算介绍英语作文Title: Introduction to Cloud Computing。
In today's digital era, cloud computing has emerged asa transformative technology, revolutionizing the way businesses and individuals store, process, and access data and applications. In this essay, we will delve into the concept of cloud computing, its components, benefits, challenges, and its impact on various aspects of our lives.At its core, cloud computing refers to the delivery of computing services – including servers, storage, databases, networking, software, analytics, and more – over the internet ("the cloud") on a pay-as-you-go basis. This model eliminates the need for organizations and individuals toown and maintain physical infrastructure, leading to cost savings, scalability, and increased efficiency.One of the key components of cloud computing is Infrastructure as a Service (IaaS), which providesvirtualized computing resources over the internet. With IaaS, users can rent virtual machines, storage, and networking components from cloud providers, enabling them to scale their infrastructure up or down based on demand without investing in physical hardware.Another essential component is Platform as a Service (PaaS), which offers a platform allowing customers to develop, run, and manage applications without worrying about the underlying infrastructure. PaaS providers deliver everything needed to support the complete lifecycle of building and delivering web-based (cloud-native) applications.Additionally, Software as a Service (SaaS) allows users to access applications hosted on the cloud over the internet. This model eliminates the need for users to install, maintain, and update software locally, as everything is managed by the service provider. Popular examples of SaaS include email services, customer relationship management (CRM) software, and productivity suites.Cloud computing offers a myriad of benefits to organizations and individuals. Firstly, it provides unparalleled scalability, allowing users to easily scale resources up or down based on demand, ensuring optimal performance and cost-efficiency. Moreover, cloud computing promotes collaboration and flexibility by enabling remote access to data and applications from any internet-connected device. Additionally, it enhances data security anddisaster recovery capabilities, as data is stored in geographically distributed data centers with robustsecurity measures in place.Despite its numerous advantages, cloud computing also poses several challenges. Security concerns, such as data breaches and compliance issues, remain a significant challenge for organizations migrating to the cloud. Moreover, ensuring data privacy and regulatory compliancein a multi-tenant environment requires robust security protocols and encryption techniques. Additionally, managing cloud costs and optimizing resource utilization can be complex, requiring organizations to implement effectivecost management strategies.In conclusion, cloud computing represents a paradigm shift in the way we consume and deliver computing services. Its scalability, flexibility, cost-effectiveness, andagility make it an indispensable technology for businesses and individuals alike. However, addressing security concerns and optimizing cost management are essential for realizing the full potential of cloud computing. As technology continues to evolve, cloud computing will undoubtedly play a central role in shaping the future of the digital landscape.。
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云计算外文翻译参考文献(文档含中英文对照即英文原文和中文翻译)原文:Technical Issues of Forensic Investigations in Cloud Computing EnvironmentsDominik BirkRuhr-University BochumHorst Goertz Institute for IT SecurityBochum, GermanyRuhr-University BochumHorst Goertz Institute for IT SecurityBochum, GermanyAbstract—Cloud Computing is arguably one of the most discussedinformation technologies today. It presents many promising technological and economical opportunities. However, many customers remain reluctant to move their business IT infrastructure completely to the cloud. One of their main concerns is Cloud Security and the threat of the unknown. Cloud Service Providers(CSP) encourage this perception by not letting their customers see what is behind their virtual curtain. A seldomly discussed, but in this regard highly relevant open issue is the ability to perform digital investigations. This continues to fuel insecurity on the sides of both providers and customers. Cloud Forensics constitutes a new and disruptive challenge for investigators. Due to the decentralized nature of data processing in the cloud, traditional approaches to evidence collection and recovery are no longer practical. This paper focuses on the technical aspects of digital forensics in distributed cloud environments. We contribute by assessing whether it is possible for the customer of cloud computing services to perform a traditional digital investigation from a technical point of view. Furthermore we discuss possible solutions and possible new methodologies helping customers to perform such investigations.I. INTRODUCTIONAlthough the cloud might appear attractive to small as well as to large companies, it does not come along without its own unique problems. Outsourcing sensitive corporate data into the cloud raises concerns regarding the privacy and security of data. Security policies, companies main pillar concerning security, cannot be easily deployed into distributed, virtualized cloud environments. This situation is further complicated by the unknown physical location of the companie’s assets. Normally,if a security incident occurs, the corporate security team wants to be able to perform their own investigation without dependency on third parties. In the cloud, this is not possible anymore: The CSP obtains all the power over the environmentand thus controls the sources of evidence. In the best case, a trusted third party acts as a trustee and guarantees for the trustworthiness of the CSP. Furthermore, the implementation of the technical architecture and circumstances within cloud computing environments bias the way an investigation may be processed. In detail, evidence data has to be interpreted by an investigator in a We would like to thank the reviewers for the helpful comments and Dennis Heinson (Center for Advanced Security Research Darmstadt - CASED) for the profound discussions regarding the legal aspects of cloud forensics. proper manner which is hardly be possible due to the lackof circumstantial information. For auditors, this situation does not change: Questions who accessed specific data and information cannot be answered by the customers, if no corresponding logs are available. With the increasing demand for using the power of the cloud for processing also sensible information and data, enterprises face the issue of Data and Process Provenance in the cloud [10]. Digital provenance, meaning meta-data that describes the ancestry or history of a digital object, is a crucial feature for forensic investigations. In combination with a suitable authentication scheme, it provides information about who created and who modified what kind of data in the cloud. These are crucial aspects for digital investigations in distributed environments such as the cloud. Unfortunately, the aspects of forensic investigations in distributed environment have so far been mostly neglected by the research community. Current discussion centers mostly around security, privacy and data protection issues [35], [9], [12]. The impact of forensic investigations on cloud environments was little noticed albeit mentioned by the authors of [1] in 2009: ”[...] to our knowledge, no research has been published on how cloud computing environments affect digital artifacts,and on acquisition logistics and legal issues related to cloud computing env ironments.” This statement is also confirmed by other authors [34], [36], [40] stressing that further research on incident handling, evidence tracking and accountability in cloud environments has to be done. At the same time, massive investments are being made in cloud technology. Combined with the fact that information technology increasingly transcendents peoples’ private and professional life, thus mirroring more and more of peoples’actions, it becomes apparent that evidence gathered from cloud environments will be of high significance to litigation or criminal proceedings in the future. Within this work, we focus the notion of cloud forensics by addressing the technical issues of forensics in all three major cloud service models and consider cross-disciplinary aspects. Moreover, we address the usability of various sources of evidence for investigative purposes and propose potential solutions to the issues from a practical standpoint. This work should be considered as a surveying discussion of an almost unexplored research area. The paper is organized as follows: We discuss the related work and the fundamental technical background information of digital forensics, cloud computing and the fault model in section II and III. In section IV, we focus on the technical issues of cloud forensics and discuss the potential sources and nature of digital evidence as well as investigations in XaaS environments including thecross-disciplinary aspects. We conclude in section V.II. RELATED WORKVarious works have been published in the field of cloud security and privacy [9], [35], [30] focussing on aspects for protecting data in multi-tenant, virtualized environments. Desired security characteristics for current cloud infrastructures mainly revolve around isolation of multi-tenant platforms [12], security of hypervisors in order to protect virtualized guest systems and secure network infrastructures [32]. Albeit digital provenance, describing the ancestry of digital objects, still remains a challenging issue for cloud environments, several works have already been published in this field [8], [10] contributing to the issues of cloud forensis. Within this context, cryptographic proofs for verifying data integrity mainly in cloud storage offers have been proposed,yet lacking of practical implementations [24], [37], [23]. Traditional computer forensics has already well researched methods for various fields of application [4], [5], [6], [11], [13]. Also the aspects of forensics in virtual systems have been addressed by several works [2], [3], [20] including the notionof virtual introspection [25]. In addition, the NIST already addressed Web Service Forensics [22] which has a huge impact on investigation processes in cloud computing environments. In contrast, the aspects of forensic investigations in cloud environments have mostly been neglected by both the industry and the research community. One of the first papers focusing on this topic was published by Wolthusen [40] after Bebee et al already introduced problems within cloud environments [1]. Wolthusen stressed that there is an inherent strong need for interdisciplinary work linking the requirements and concepts of evidence arising from the legal field to what can be feasibly reconstructed and inferred algorithmically or in an exploratory manner. In 2010, Grobauer et al [36] published a paper discussing the issues of incident response in cloud environments - unfortunately no specific issues and solutions of cloud forensics have been proposed which will be done within this work.III. TECHNICAL BACKGROUNDA. Traditional Digital ForensicsThe notion of Digital Forensics is widely known as the practice of identifying, extracting and considering evidence from digital media. Unfortunately, digital evidence is both fragile and volatile and therefore requires the attention of special personnel and methods in order to ensure that evidence data can be proper isolated and evaluated. Normally, the process of a digital investigation can be separated into three different steps each having its own specificpurpose:1) In the Securing Phase, the major intention is the preservation of evidence for analysis. The data has to be collected in a manner that maximizes its integrity. This is normally done by a bitwise copy of the original media. As can be imagined, this represents a huge problem in the field of cloud computing where you never know exactly where your data is and additionallydo not have access to any physical hardware. However, the snapshot technology, discussed in section IV-B3, provides a powerful tool to freeze system states and thus makes digital investigations, at least in IaaS scenarios, theoretically possible.2) We refer to the Analyzing Phase as the stage in which the data is sifted and combined. It is in this phase that the data from multiple systems or sources is pulled together to create as complete a picture and event reconstruction as possible. Especially in distributed system infrastructures, this means that bits and pieces of data are pulled together for deciphering the real story of what happened and for providing a deeper look into the data.3) Finally, at the end of the examination and analysis of the data, the results of the previous phases will be reprocessed in the Presentation Phase. The report, created in this phase, is a compilation of all the documentation and evidence from the analysis stage. The main intention of such a report is that it contains all results, it is complete and clear to understand. Apparently, the success of these three steps strongly depends on the first stage. If it is not possible to secure the complete set of evidence data, no exhaustive analysis will be possible. However, in real world scenarios often only a subset of the evidence data can be secured by the investigator. In addition, an important definition in the general context of forensics is the notion of a Chain of Custody. This chain clarifies how and where evidence is stored and who takes possession of it. Especially for cases which are brought to court it is crucial that the chain of custody is preserved.B. Cloud ComputingAccording to the NIST [16], cloud computing is a model for enabling convenient, on-demand network access to a shared pool of configurable computing resources (e.g., networks, servers, storage, applications and services) that can be rapidly provisioned and released with minimal CSP interaction. The new raw definition of cloud computing brought several new characteristics such as multi-tenancy, elasticity, pay-as-you-go and reliability. Within this work, the following three models are used: In the Infrastructure asa Service (IaaS) model, the customer is using the virtual machine provided by the CSP for installing his own system on it. The system can be used like any other physical computer with a few limitations. However, the additive customer power over the system comes along with additional security obligations. Platform as a Service (PaaS) offerings provide the capability to deploy application packages created using the virtual development environment supported by the CSP. For the efficiency of software development process this service model can be propellent. In the Software as a Service (SaaS) model, the customer makes use of a service run by the CSP on a cloud infrastructure. In most of the cases this service can be accessed through an API for a thin client interface such as a web browser. Closed-source public SaaS offers such as Amazon S3 and GoogleMail can only be used in the public deployment model leading to further issues concerning security, privacy and the gathering of suitable evidences. Furthermore, two main deployment models, private and public cloud have to be distinguished. Common public clouds are made available to the general public. The corresponding infrastructure is owned by one organization acting as a CSP and offering services to its customers. In contrast, the private cloud is exclusively operated for an organization but may not provide the scalability and agility of public offers. The additional notions of community and hybrid cloud are not exclusively covered within this work. However, independently from the specific model used, the movement of applications and data to the cloud comes along with limited control for the customer about the application itself, the data pushed into the applications and also about the underlying technical infrastructure.C. Fault ModelBe it an account for a SaaS application, a development environment (PaaS) or a virtual image of an IaaS environment, systems in the cloud can be affected by inconsistencies. Hence, for both customer and CSP it is crucial to have the ability to assign faults to the causing party, even in the presence of Byzantine behavior [33]. Generally, inconsistencies can be caused by the following two reasons:1) Maliciously Intended FaultsInternal or external adversaries with specific malicious intentions can cause faults on cloud instances or applications. Economic rivals as well as former employees can be the reason for these faults and state a constant threat to customers and CSP. In this model, also a malicious CSP is included albeit he isassumed to be rare in real world scenarios. Additionally, from the technical point of view, the movement of computing power to a virtualized, multi-tenant environment can pose further threads and risks to the systems. One reason for this is that if a single system or service in the cloud is compromised, all other guest systems and even the host system are at risk. Hence, besides the need for further security measures, precautions for potential forensic investigations have to be taken into consideration.2) Unintentional FaultsInconsistencies in technical systems or processes in the cloud do not have implicitly to be caused by malicious intent. Internal communication errors or human failures can lead to issues in the services offered to the costumer(i.e. loss or modification of data). Although these failures are not caused intentionally, both the CSP and the customer have a strong intention to discover the reasons and deploy corresponding fixes.IV. TECHNICAL ISSUESDigital investigations are about control of forensic evidence data. From the technical standpoint, this data can be available in three different states: at rest, in motion or in execution. Data at rest is represented by allocated disk space. Whether the data is stored in a database or in a specific file format, it allocates disk space. Furthermore, if a file is deleted, the disk space is de-allocated for the operating system but the data is still accessible since the disk space has not been re-allocated and overwritten. This fact is often exploited by investigators which explore these de-allocated disk space on harddisks. In case the data is in motion, data is transferred from one entity to another e.g. a typical file transfer over a network can be seen as a data in motion scenario. Several encapsulated protocols contain the data each leaving specific traces on systems and network devices which can in return be used by investigators. Data can be loaded into memory and executed as a process. In this case, the data is neither at rest or in motion but in execution. On the executing system, process information, machine instruction and allocated/de-allocated data can be analyzed by creating a snapshot of the current system state. In the following sections, we point out the potential sources for evidential data in cloud environments and discuss the technical issues of digital investigations in XaaS environmentsas well as suggest several solutions to these problems.A. Sources and Nature of EvidenceConcerning the technical aspects of forensic investigations, the amount of potential evidence available to the investigator strongly diverges between thedifferent cloud service and deployment models. The virtual machine (VM), hosting in most of the cases the server application, provides several pieces of information that could be used by investigators. On the network level, network components can provide information about possible communication channels between different parties involved. The browser on the client, acting often as the user agent for communicating with the cloud, also contains a lot of information that could be used as evidence in a forensic investigation. Independently from the used model, the following three components could act as sources for potential evidential data.1) Virtual Cloud Instance: The VM within the cloud, where i.e. data is stored or processes are handled, contains potential evidence [2], [3]. In most of the cases, it is the place where an incident happened and hence provides a good starting point for a forensic investigation. The VM instance can be accessed by both, the CSP and the customer who is running the instance. Furthermore, virtual introspection techniques [25] provide access to the runtime state of the VM via the hypervisor and snapshot technology supplies a powerful technique for the customer to freeze specific states of the VM. Therefore, virtual instances can be still running during analysis which leads to the case of live investigations [41] or can be turned off leading to static image analysis. In SaaS and PaaS scenarios, the ability to access the virtual instance for gathering evidential information is highly limited or simply not possible.2) Network Layer: Traditional network forensics is knownas the analysis of network traffic logs for tracing events that have occurred in the past. Since the different ISO/OSI network layers provide several information on protocols and communication between instances within as well as with instances outside the cloud [4], [5], [6], network forensics is theoretically also feasible in cloud environments. However in practice, ordinary CSP currently do not provide any log data from the network components used by the customer’s instances or applications. For instance, in case of a malware infection of an IaaS VM, it will be difficult for the investigator to get any form of routing information and network log datain general which is crucial for further investigative steps. This situation gets even more complicated in case of PaaS or SaaS. So again, the situation of gathering forensic evidence is strongly affected by the support the investigator receives from the customer and the CSP.3) Client System: On the system layer of the client, it completely depends on the used model (IaaS, PaaS, SaaS) if and where potential evidence could beextracted. In most of the scenarios, the user agent (e.g. the web browser) on the client system is the only application that communicates with the service in the cloud. This especially holds for SaaS applications which are used and controlled by the web browser. But also in IaaS scenarios, the administration interface is often controlled via the browser. Hence, in an exhaustive forensic investigation, the evidence data gathered from the browser environment [7] should not be omitted.a) Browser Forensics: Generally, the circumstances leading to an investigation have to be differentiated: In ordinary scenarios, the main goal of an investigation of the web browser is to determine if a user has been victim of a crime. In complex SaaS scenarios with high client-server interaction, this constitutes a difficult task. Additionally, customers strongly make use of third-party extensions [17] which can be abused for malicious purposes. Hence, the investigator might want to look for malicious extensions, searches performed, websites visited, files downloaded, information entered in forms or stored in local HTML5 stores, web-based email contents and persistent browser cookies for gathering potential evidence data. Within this context, it is inevitable to investigate the appearance of malicious JavaScript [18] leading to e.g. unintended AJAX requests and hence modified usage of administration interfaces. Generally, the web browser contains a lot of electronic evidence data that could be used to give an answer to both of the above questions - even if the private mode is switched on [19].B. Investigations in XaaS EnvironmentsTraditional digital forensic methodologies permit investigators to seize equipment and perform detailed analysis on the media and data recovered [11]. In a distributed infrastructure organization like the cloud computing environment, investigators are confronted with an entirely different situation. They have no longer the option of seizing physical data storage. Data and processes of the customer are dispensed over an undisclosed amount of virtual instances, applications and network elements. Hence, it is in question whether preliminary findings of the computer forensic community in the field of digital forensics apparently have to be revised and adapted to the new environment. Within this section, specific issues of investigations in SaaS, PaaS and IaaS environments will be discussed. In addition, cross-disciplinary issues which affect several environments uniformly, will be taken into consideration. We also suggest potential solutions to the mentioned problems.1) SaaS Environments: Especially in the SaaS model, the customer does notobtain any control of the underlying operating infrastructure such as network, servers, operating systems or the application that is used. This means that no deeper view into the system and its underlying infrastructure is provided to the customer. Only limited userspecific application configuration settings can be controlled contributing to the evidences which can be extracted fromthe client (see section IV-A3). In a lot of cases this urges the investigator to rely on high-level logs which are eventually provided by the CSP. Given the case that the CSP does not run any logging application, the customer has no opportunity to create any useful evidence through the installation of any toolkit or logging tool. These circumstances do not allow a valid forensic investigation and lead to the assumption that customers of SaaS offers do not have any chance to analyze potential incidences.a) Data Provenance: The notion of Digital Provenance is known as meta-data that describes the ancestry or history of digital objects. Secure provenance that records ownership and process history of data objects is vital to the success of data forensics in cloud environments, yet it is still a challenging issue today [8]. Albeit data provenance is of high significance also for IaaS and PaaS, it states a huge problem specifically for SaaS-based applications: Current global acting public SaaS CSP offer Single Sign-On (SSO) access control to the set of their services. Unfortunately in case of an account compromise, most of the CSP do not offer any possibility for the customer to figure out which data and information has been accessed by the adversary. For the victim, this situation can have tremendous impact: If sensitive data has been compromised, it is unclear which data has been leaked and which has not been accessed by the adversary. Additionally, data could be modified or deleted by an external adversary or even by the CSP e.g. due to storage reasons. The customer has no ability to proof otherwise. Secure provenance mechanisms for distributed environments can improve this situation but have not been practically implemented by CSP [10]. Suggested Solution: In private SaaS scenarios this situation is improved by the fact that the customer and the CSP are probably under the same authority. Hence, logging and provenance mechanisms could be implemented which contribute to potential investigations. Additionally, the exact location of the servers and the data is known at any time. Public SaaS CSP should offer additional interfaces for the purpose of compliance, forensics, operations and security matters to their customers. Through an API, the customers should have the ability to receive specific information suchas access, error and event logs that could improve their situation in case of aninvestigation. Furthermore, due to the limited ability of receiving forensic information from the server and proofing integrity of stored data in SaaS scenarios, the client has to contribute to this process. This could be achieved by implementing Proofs of Retrievability (POR) in which a verifier (client) is enabled to determine that a prover (server) possesses a file or data object and it can be retrieved unmodified [24]. Provable Data Possession (PDP) techniques [37] could be used to verify that an untrusted server possesses the original data without the need for the client to retrieve it. Although these cryptographic proofs have not been implemented by any CSP, the authors of [23] introduced a new data integrity verification mechanism for SaaS scenarios which could also be used for forensic purposes.2) PaaS Environments: One of the main advantages of the PaaS model is that the developed software application is under the control of the customer and except for some CSP, the source code of the application does not have to leave the local development environment. Given these circumstances, the customer obtains theoretically the power to dictate how the application interacts with other dependencies such as databases, storage entities etc. CSP normally claim this transfer is encrypted but this statement can hardly be verified by the customer. Since the customer has the ability to interact with the platform over a prepared API, system states and specific application logs can be extracted. However potential adversaries, which can compromise the application during runtime, should not be able to alter these log files afterwards. Suggested Solution:Depending on the runtime environment, logging mechanisms could be implemented which automatically sign and encrypt the log information before its transfer to a central logging server under the control of the customer. Additional signing and encrypting could prevent potential eavesdroppers from being able to view and alter log data information on the way to the logging server. Runtime compromise of an PaaS application by adversaries could be monitored by push-only mechanisms for log data presupposing that the needed information to detect such an attack are logged. Increasingly, CSP offering PaaS solutions give developers the ability to collect and store a variety of diagnostics data in a highly configurable way with the help of runtime feature sets [38].3) IaaS Environments: As expected, even virtual instances in the cloud get compromised by adversaries. Hence, the ability to determine how defenses in the virtual environment failed and to what extent the affected systems havebeen compromised is crucial not only for recovering from an incident. Also forensic investigations gain leverage from such information and contribute to resilience against future attacks on the systems. From the forensic point of view, IaaS instances do provide much more evidence data usable for potential forensics than PaaS and SaaS models do. This fact is caused throughthe ability of the customer to install and set up the image for forensic purposes before an incident occurs. Hence, as proposed for PaaS environments, log data and other forensic evidence information could be signed and encrypted before itis transferred to third-party hosts mitigating the chance that a maliciously motivated shutdown process destroys the volatile data. Although, IaaS environments provide plenty of potential evidence, it has to be emphasized that the customer VM is in the end still under the control of the CSP. He controls the hypervisor which is e.g. responsible for enforcing hardware boundaries and routing hardware requests among different VM. Hence, besides the security responsibilities of the hypervisor, he exerts tremendous control over how customer’s VM communicate with the hardware and theoretically can intervene executed processes on the hosted virtual instance through virtual introspection [25]. This could also affect encryption or signing processes executed on the VM and therefore leading to the leakage of the secret key. Although this risk can be disregarded in most of the cases, the impact on the security of high security environments is tremendous.a) Snapshot Analysis: Traditional forensics expect target machines to be powered down to collect an image (dead virtual instance). This situation completely changed with the advent of the snapshot technology which is supported by all popular hypervisors such as Xen, VMware ESX and Hyper-V.A snapshot, also referred to as the forensic image of a VM, providesa powerful tool with which a virtual instance can be clonedby one click including also the running system’s mem ory. Due to the invention of the snapshot technology, systems hosting crucial business processes do not have to be powered down for forensic investigation purposes. The investigator simply creates and loads a snapshot of the target VM for analysis(live virtual instance). This behavior is especially important for scenarios in which a downtime of a system is not feasible or practical due to existing SLA. However the information whether the machine is running or has been properly powered down is crucial [3] for the investigation. Live investigations of running virtual instances become more common providing evidence data that。
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云计算外文翻译参考文献(文档含中英文对照即英文原文和中文翻译)原文:Technical Issues of Forensic Investigations in Cloud Computing EnvironmentsDominik BirkRuhr-University BochumHorst Goertz Institute for IT SecurityBochum, GermanyRuhr-University BochumHorst Goertz Institute for IT SecurityBochum, GermanyAbstract—Cloud Computing is arguably one of the most discussedinformation technologies today. It presents many promising technological and economical opportunities. However, many customers remain reluctant to move their business IT infrastructure completely to the cloud. One of their main concerns is Cloud Security and the threat of the unknown. Cloud Service Providers(CSP) encourage this perception by not letting their customers see what is behind their virtual curtain. A seldomly discussed, but in this regard highly relevant open issue is the ability to perform digital investigations. This continues to fuel insecurity on the sides of both providers and customers. Cloud Forensics constitutes a new and disruptive challenge for investigators. Due to the decentralized nature of data processing in the cloud, traditional approaches to evidence collection and recovery are no longer practical. This paper focuses on the technical aspects of digital forensics in distributed cloud environments. We contribute by assessing whether it is possible for the customer of cloud computing services to perform a traditional digital investigation from a technical point of view. Furthermore we discuss possible solutions and possible new methodologies helping customers to perform such investigations.I. INTRODUCTIONAlthough the cloud might appear attractive to small as well as to large companies, it does not come along without its own unique problems. Outsourcing sensitive corporate data into the cloud raises concerns regarding the privacy and security of data. Security policies, companies main pillar concerning security, cannot be easily deployed into distributed, virtualized cloud environments. This situation is further complicated by the unknown physical location of the companie’s assets. Normally,if a security incident occurs, the corporate security team wants to be able to perform their own investigation without dependency on third parties. In the cloud, this is not possible anymore: The CSP obtains all the power over the environmentand thus controls the sources of evidence. In the best case, a trusted third party acts as a trustee and guarantees for the trustworthiness of the CSP. Furthermore, the implementation of the technical architecture and circumstances within cloud computing environments bias the way an investigation may be processed. In detail, evidence data has to be interpreted by an investigator in a We would like to thank the reviewers for the helpful comments and Dennis Heinson (Center for Advanced Security Research Darmstadt - CASED) for the profound discussions regarding the legal aspects of cloud forensics. proper manner which is hardly be possible due to the lackof circumstantial information. For auditors, this situation does not change: Questions who accessed specific data and information cannot be answered by the customers, if no corresponding logs are available. With the increasing demand for using the power of the cloud for processing also sensible information and data, enterprises face the issue of Data and Process Provenance in the cloud [10]. Digital provenance, meaning meta-data that describes the ancestry or history of a digital object, is a crucial feature for forensic investigations. In combination with a suitable authentication scheme, it provides information about who created and who modified what kind of data in the cloud. These are crucial aspects for digital investigations in distributed environments such as the cloud. Unfortunately, the aspects of forensic investigations in distributed environment have so far been mostly neglected by the research community. Current discussion centers mostly around security, privacy and data protection issues [35], [9], [12]. The impact of forensic investigations on cloud environments was little noticed albeit mentioned by the authors of [1] in 2009: ”[...] to our knowledge, no research has been published on how cloud computing environments affect digital artifacts,and on acquisition logistics and legal issues related to cloud computing env ironments.” This statement is also confirmed by other authors [34], [36], [40] stressing that further research on incident handling, evidence tracking and accountability in cloud environments has to be done. At the same time, massive investments are being made in cloud technology. Combined with the fact that information technology increasingly transcendents peoples’ private and professional life, thus mirroring more and more of peoples’actions, it becomes apparent that evidence gathered from cloud environments will be of high significance to litigation or criminal proceedings in the future. Within this work, we focus the notion of cloud forensics by addressing the technical issues of forensics in all three major cloud service models and consider cross-disciplinary aspects. Moreover, we address the usability of various sources of evidence for investigative purposes and propose potential solutions to the issues from a practical standpoint. This work should be considered as a surveying discussion of an almost unexplored research area. The paper is organized as follows: We discuss the related work and the fundamental technical background information of digital forensics, cloud computing and the fault model in section II and III. In section IV, we focus on the technical issues of cloud forensics and discuss the potential sources and nature of digital evidence as well as investigations in XaaS environments including thecross-disciplinary aspects. We conclude in section V.II. RELATED WORKVarious works have been published in the field of cloud security and privacy [9], [35], [30] focussing on aspects for protecting data in multi-tenant, virtualized environments. Desired security characteristics for current cloud infrastructures mainly revolve around isolation of multi-tenant platforms [12], security of hypervisors in order to protect virtualized guest systems and secure network infrastructures [32]. Albeit digital provenance, describing the ancestry of digital objects, still remains a challenging issue for cloud environments, several works have already been published in this field [8], [10] contributing to the issues of cloud forensis. Within this context, cryptographic proofs for verifying data integrity mainly in cloud storage offers have been proposed,yet lacking of practical implementations [24], [37], [23]. Traditional computer forensics has already well researched methods for various fields of application [4], [5], [6], [11], [13]. Also the aspects of forensics in virtual systems have been addressed by several works [2], [3], [20] including the notionof virtual introspection [25]. In addition, the NIST already addressed Web Service Forensics [22] which has a huge impact on investigation processes in cloud computing environments. In contrast, the aspects of forensic investigations in cloud environments have mostly been neglected by both the industry and the research community. One of the first papers focusing on this topic was published by Wolthusen [40] after Bebee et al already introduced problems within cloud environments [1]. Wolthusen stressed that there is an inherent strong need for interdisciplinary work linking the requirements and concepts of evidence arising from the legal field to what can be feasibly reconstructed and inferred algorithmically or in an exploratory manner. In 2010, Grobauer et al [36] published a paper discussing the issues of incident response in cloud environments - unfortunately no specific issues and solutions of cloud forensics have been proposed which will be done within this work.III. TECHNICAL BACKGROUNDA. Traditional Digital ForensicsThe notion of Digital Forensics is widely known as the practice of identifying, extracting and considering evidence from digital media. Unfortunately, digital evidence is both fragile and volatile and therefore requires the attention of special personnel and methods in order to ensure that evidence data can be proper isolated and evaluated. Normally, the process of a digital investigation can be separated into three different steps each having its own specificpurpose:1) In the Securing Phase, the major intention is the preservation of evidence for analysis. The data has to be collected in a manner that maximizes its integrity. This is normally done by a bitwise copy of the original media. As can be imagined, this represents a huge problem in the field of cloud computing where you never know exactly where your data is and additionallydo not have access to any physical hardware. However, the snapshot technology, discussed in section IV-B3, provides a powerful tool to freeze system states and thus makes digital investigations, at least in IaaS scenarios, theoretically possible.2) We refer to the Analyzing Phase as the stage in which the data is sifted and combined. It is in this phase that the data from multiple systems or sources is pulled together to create as complete a picture and event reconstruction as possible. Especially in distributed system infrastructures, this means that bits and pieces of data are pulled together for deciphering the real story of what happened and for providing a deeper look into the data.3) Finally, at the end of the examination and analysis of the data, the results of the previous phases will be reprocessed in the Presentation Phase. The report, created in this phase, is a compilation of all the documentation and evidence from the analysis stage. The main intention of such a report is that it contains all results, it is complete and clear to understand. Apparently, the success of these three steps strongly depends on the first stage. If it is not possible to secure the complete set of evidence data, no exhaustive analysis will be possible. However, in real world scenarios often only a subset of the evidence data can be secured by the investigator. In addition, an important definition in the general context of forensics is the notion of a Chain of Custody. This chain clarifies how and where evidence is stored and who takes possession of it. Especially for cases which are brought to court it is crucial that the chain of custody is preserved.B. Cloud ComputingAccording to the NIST [16], cloud computing is a model for enabling convenient, on-demand network access to a shared pool of configurable computing resources (e.g., networks, servers, storage, applications and services) that can be rapidly provisioned and released with minimal CSP interaction. The new raw definition of cloud computing brought several new characteristics such as multi-tenancy, elasticity, pay-as-you-go and reliability. Within this work, the following three models are used: In the Infrastructure asa Service (IaaS) model, the customer is using the virtual machine provided by the CSP for installing his own system on it. The system can be used like any other physical computer with a few limitations. However, the additive customer power over the system comes along with additional security obligations. Platform as a Service (PaaS) offerings provide the capability to deploy application packages created using the virtual development environment supported by the CSP. For the efficiency of software development process this service model can be propellent. In the Software as a Service (SaaS) model, the customer makes use of a service run by the CSP on a cloud infrastructure. In most of the cases this service can be accessed through an API for a thin client interface such as a web browser. Closed-source public SaaS offers such as Amazon S3 and GoogleMail can only be used in the public deployment model leading to further issues concerning security, privacy and the gathering of suitable evidences. Furthermore, two main deployment models, private and public cloud have to be distinguished. Common public clouds are made available to the general public. The corresponding infrastructure is owned by one organization acting as a CSP and offering services to its customers. In contrast, the private cloud is exclusively operated for an organization but may not provide the scalability and agility of public offers. The additional notions of community and hybrid cloud are not exclusively covered within this work. However, independently from the specific model used, the movement of applications and data to the cloud comes along with limited control for the customer about the application itself, the data pushed into the applications and also about the underlying technical infrastructure.C. Fault ModelBe it an account for a SaaS application, a development environment (PaaS) or a virtual image of an IaaS environment, systems in the cloud can be affected by inconsistencies. Hence, for both customer and CSP it is crucial to have the ability to assign faults to the causing party, even in the presence of Byzantine behavior [33]. Generally, inconsistencies can be caused by the following two reasons:1) Maliciously Intended FaultsInternal or external adversaries with specific malicious intentions can cause faults on cloud instances or applications. Economic rivals as well as former employees can be the reason for these faults and state a constant threat to customers and CSP. In this model, also a malicious CSP is included albeit he isassumed to be rare in real world scenarios. Additionally, from the technical point of view, the movement of computing power to a virtualized, multi-tenant environment can pose further threads and risks to the systems. One reason for this is that if a single system or service in the cloud is compromised, all other guest systems and even the host system are at risk. Hence, besides the need for further security measures, precautions for potential forensic investigations have to be taken into consideration.2) Unintentional FaultsInconsistencies in technical systems or processes in the cloud do not have implicitly to be caused by malicious intent. Internal communication errors or human failures can lead to issues in the services offered to the costumer(i.e. loss or modification of data). Although these failures are not caused intentionally, both the CSP and the customer have a strong intention to discover the reasons and deploy corresponding fixes.IV. TECHNICAL ISSUESDigital investigations are about control of forensic evidence data. From the technical standpoint, this data can be available in three different states: at rest, in motion or in execution. Data at rest is represented by allocated disk space. Whether the data is stored in a database or in a specific file format, it allocates disk space. Furthermore, if a file is deleted, the disk space is de-allocated for the operating system but the data is still accessible since the disk space has not been re-allocated and overwritten. This fact is often exploited by investigators which explore these de-allocated disk space on harddisks. In case the data is in motion, data is transferred from one entity to another e.g. a typical file transfer over a network can be seen as a data in motion scenario. Several encapsulated protocols contain the data each leaving specific traces on systems and network devices which can in return be used by investigators. Data can be loaded into memory and executed as a process. In this case, the data is neither at rest or in motion but in execution. On the executing system, process information, machine instruction and allocated/de-allocated data can be analyzed by creating a snapshot of the current system state. In the following sections, we point out the potential sources for evidential data in cloud environments and discuss the technical issues of digital investigations in XaaS environmentsas well as suggest several solutions to these problems.A. Sources and Nature of EvidenceConcerning the technical aspects of forensic investigations, the amount of potential evidence available to the investigator strongly diverges between thedifferent cloud service and deployment models. The virtual machine (VM), hosting in most of the cases the server application, provides several pieces of information that could be used by investigators. On the network level, network components can provide information about possible communication channels between different parties involved. The browser on the client, acting often as the user agent for communicating with the cloud, also contains a lot of information that could be used as evidence in a forensic investigation. Independently from the used model, the following three components could act as sources for potential evidential data.1) Virtual Cloud Instance: The VM within the cloud, where i.e. data is stored or processes are handled, contains potential evidence [2], [3]. In most of the cases, it is the place where an incident happened and hence provides a good starting point for a forensic investigation. The VM instance can be accessed by both, the CSP and the customer who is running the instance. Furthermore, virtual introspection techniques [25] provide access to the runtime state of the VM via the hypervisor and snapshot technology supplies a powerful technique for the customer to freeze specific states of the VM. Therefore, virtual instances can be still running during analysis which leads to the case of live investigations [41] or can be turned off leading to static image analysis. In SaaS and PaaS scenarios, the ability to access the virtual instance for gathering evidential information is highly limited or simply not possible.2) Network Layer: Traditional network forensics is knownas the analysis of network traffic logs for tracing events that have occurred in the past. Since the different ISO/OSI network layers provide several information on protocols and communication between instances within as well as with instances outside the cloud [4], [5], [6], network forensics is theoretically also feasible in cloud environments. However in practice, ordinary CSP currently do not provide any log data from the network components used by the customer’s instances or applications. For instance, in case of a malware infection of an IaaS VM, it will be difficult for the investigator to get any form of routing information and network log datain general which is crucial for further investigative steps. This situation gets even more complicated in case of PaaS or SaaS. So again, the situation of gathering forensic evidence is strongly affected by the support the investigator receives from the customer and the CSP.3) Client System: On the system layer of the client, it completely depends on the used model (IaaS, PaaS, SaaS) if and where potential evidence could beextracted. In most of the scenarios, the user agent (e.g. the web browser) on the client system is the only application that communicates with the service in the cloud. This especially holds for SaaS applications which are used and controlled by the web browser. But also in IaaS scenarios, the administration interface is often controlled via the browser. Hence, in an exhaustive forensic investigation, the evidence data gathered from the browser environment [7] should not be omitted.a) Browser Forensics: Generally, the circumstances leading to an investigation have to be differentiated: In ordinary scenarios, the main goal of an investigation of the web browser is to determine if a user has been victim of a crime. In complex SaaS scenarios with high client-server interaction, this constitutes a difficult task. Additionally, customers strongly make use of third-party extensions [17] which can be abused for malicious purposes. Hence, the investigator might want to look for malicious extensions, searches performed, websites visited, files downloaded, information entered in forms or stored in local HTML5 stores, web-based email contents and persistent browser cookies for gathering potential evidence data. Within this context, it is inevitable to investigate the appearance of malicious JavaScript [18] leading to e.g. unintended AJAX requests and hence modified usage of administration interfaces. Generally, the web browser contains a lot of electronic evidence data that could be used to give an answer to both of the above questions - even if the private mode is switched on [19].B. Investigations in XaaS EnvironmentsTraditional digital forensic methodologies permit investigators to seize equipment and perform detailed analysis on the media and data recovered [11]. In a distributed infrastructure organization like the cloud computing environment, investigators are confronted with an entirely different situation. They have no longer the option of seizing physical data storage. Data and processes of the customer are dispensed over an undisclosed amount of virtual instances, applications and network elements. Hence, it is in question whether preliminary findings of the computer forensic community in the field of digital forensics apparently have to be revised and adapted to the new environment. Within this section, specific issues of investigations in SaaS, PaaS and IaaS environments will be discussed. In addition, cross-disciplinary issues which affect several environments uniformly, will be taken into consideration. We also suggest potential solutions to the mentioned problems.1) SaaS Environments: Especially in the SaaS model, the customer does notobtain any control of the underlying operating infrastructure such as network, servers, operating systems or the application that is used. This means that no deeper view into the system and its underlying infrastructure is provided to the customer. Only limited userspecific application configuration settings can be controlled contributing to the evidences which can be extracted fromthe client (see section IV-A3). In a lot of cases this urges the investigator to rely on high-level logs which are eventually provided by the CSP. Given the case that the CSP does not run any logging application, the customer has no opportunity to create any useful evidence through the installation of any toolkit or logging tool. These circumstances do not allow a valid forensic investigation and lead to the assumption that customers of SaaS offers do not have any chance to analyze potential incidences.a) Data Provenance: The notion of Digital Provenance is known as meta-data that describes the ancestry or history of digital objects. Secure provenance that records ownership and process history of data objects is vital to the success of data forensics in cloud environments, yet it is still a challenging issue today [8]. Albeit data provenance is of high significance also for IaaS and PaaS, it states a huge problem specifically for SaaS-based applications: Current global acting public SaaS CSP offer Single Sign-On (SSO) access control to the set of their services. Unfortunately in case of an account compromise, most of the CSP do not offer any possibility for the customer to figure out which data and information has been accessed by the adversary. For the victim, this situation can have tremendous impact: If sensitive data has been compromised, it is unclear which data has been leaked and which has not been accessed by the adversary. Additionally, data could be modified or deleted by an external adversary or even by the CSP e.g. due to storage reasons. The customer has no ability to proof otherwise. Secure provenance mechanisms for distributed environments can improve this situation but have not been practically implemented by CSP [10]. Suggested Solution: In private SaaS scenarios this situation is improved by the fact that the customer and the CSP are probably under the same authority. Hence, logging and provenance mechanisms could be implemented which contribute to potential investigations. Additionally, the exact location of the servers and the data is known at any time. Public SaaS CSP should offer additional interfaces for the purpose of compliance, forensics, operations and security matters to their customers. Through an API, the customers should have the ability to receive specific information suchas access, error and event logs that could improve their situation in case of aninvestigation. Furthermore, due to the limited ability of receiving forensic information from the server and proofing integrity of stored data in SaaS scenarios, the client has to contribute to this process. This could be achieved by implementing Proofs of Retrievability (POR) in which a verifier (client) is enabled to determine that a prover (server) possesses a file or data object and it can be retrieved unmodified [24]. Provable Data Possession (PDP) techniques [37] could be used to verify that an untrusted server possesses the original data without the need for the client to retrieve it. Although these cryptographic proofs have not been implemented by any CSP, the authors of [23] introduced a new data integrity verification mechanism for SaaS scenarios which could also be used for forensic purposes.2) PaaS Environments: One of the main advantages of the PaaS model is that the developed software application is under the control of the customer and except for some CSP, the source code of the application does not have to leave the local development environment. Given these circumstances, the customer obtains theoretically the power to dictate how the application interacts with other dependencies such as databases, storage entities etc. CSP normally claim this transfer is encrypted but this statement can hardly be verified by the customer. Since the customer has the ability to interact with the platform over a prepared API, system states and specific application logs can be extracted. However potential adversaries, which can compromise the application during runtime, should not be able to alter these log files afterwards. Suggested Solution:Depending on the runtime environment, logging mechanisms could be implemented which automatically sign and encrypt the log information before its transfer to a central logging server under the control of the customer. Additional signing and encrypting could prevent potential eavesdroppers from being able to view and alter log data information on the way to the logging server. Runtime compromise of an PaaS application by adversaries could be monitored by push-only mechanisms for log data presupposing that the needed information to detect such an attack are logged. Increasingly, CSP offering PaaS solutions give developers the ability to collect and store a variety of diagnostics data in a highly configurable way with the help of runtime feature sets [38].3) IaaS Environments: As expected, even virtual instances in the cloud get compromised by adversaries. Hence, the ability to determine how defenses in the virtual environment failed and to what extent the affected systems havebeen compromised is crucial not only for recovering from an incident. Also forensic investigations gain leverage from such information and contribute to resilience against future attacks on the systems. From the forensic point of view, IaaS instances do provide much more evidence data usable for potential forensics than PaaS and SaaS models do. This fact is caused throughthe ability of the customer to install and set up the image for forensic purposes before an incident occurs. Hence, as proposed for PaaS environments, log data and other forensic evidence information could be signed and encrypted before itis transferred to third-party hosts mitigating the chance that a maliciously motivated shutdown process destroys the volatile data. Although, IaaS environments provide plenty of potential evidence, it has to be emphasized that the customer VM is in the end still under the control of the CSP. He controls the hypervisor which is e.g. responsible for enforcing hardware boundaries and routing hardware requests among different VM. Hence, besides the security responsibilities of the hypervisor, he exerts tremendous control over how customer’s VM communicate with the hardware and theoretically can intervene executed processes on the hosted virtual instance through virtual introspection [25]. This could also affect encryption or signing processes executed on the VM and therefore leading to the leakage of the secret key. Although this risk can be disregarded in most of the cases, the impact on the security of high security environments is tremendous.a) Snapshot Analysis: Traditional forensics expect target machines to be powered down to collect an image (dead virtual instance). This situation completely changed with the advent of the snapshot technology which is supported by all popular hypervisors such as Xen, VMware ESX and Hyper-V.A snapshot, also referred to as the forensic image of a VM, providesa powerful tool with which a virtual instance can be clonedby one click including also the running system’s mem ory. Due to the invention of the snapshot technology, systems hosting crucial business processes do not have to be powered down for forensic investigation purposes. The investigator simply creates and loads a snapshot of the target VM for analysis(live virtual instance). This behavior is especially important for scenarios in which a downtime of a system is not feasible or practical due to existing SLA. However the information whether the machine is running or has been properly powered down is crucial [3] for the investigation. Live investigations of running virtual instances become more common providing evidence data that。
云计算外文文献+翻译
云计算外文文献+翻译1. 引言云计算是一种基于互联网的计算方式，它通过共享的计算资源提供各种服务。
随着云计算的普及和应用，许多研究者对该领域进行了深入的研究。
本文将介绍一篇外文文献，探讨云计算的相关内容，并提供相应的翻译。
2. 外文文献概述作者：Antonio Fernández Anta, Chryssis Georgiou, Evangelos Kranakis出版年份：2019年该外文文献主要综述了云计算的发展和应用。
文中介绍了云计算的基本概念，包括云计算的特点、架构、服务模型以及云计算的挑战和前景。
3. 研究内容该研究综述了云计算技术的基本概念和相关技术。
文中首先介绍了云计算的定义和其与传统计算的比较，深入探讨了云计算的优势和不足之处。
随后，文中介绍了云计算的架构，包括云服务提供商、云服务消费者和云服务的基本组件。
在架构介绍之后，文中提供了云计算的三种服务模型：基础设施即服务（IaaS）、平台即服务（PaaS）和软件即服务（SaaS）。
每种服务模型都从定义、特点和应用案例方面进行了介绍，并为读者提供了更深入的了解。
此外，文中还讨论了云计算的挑战，包括安全性、隐私保护、性能和可靠性等方面的问题。
同时，文中也探讨了云计算的前景和未来发展方向。
4. 文献翻译《云计算：一项调查》是一篇全面介绍云计算的文献。
它详细解释了云计算的定义、架构和服务模型，并探讨了其优势、不足和挑战。
此外，该文献还对云计算的未来发展进行了预测。
对于研究云计算和相关领域的读者来说，该文献提供了一个很好的参考资源。
它可以帮助读者了解云计算的基本概念、架构和服务模型，也可以引导读者思考云计算面临的挑战和应对方法。
5. 结论。
英语作文 关于云计算
英语作文关于云计算Title: The Evolution and Impact of Cloud Computing。
Cloud computing has emerged as a transformative force in the realm of technology, revolutionizing the way individuals and organizations store, access, and process data. This paradigm shift has brought about significant advancements in efficiency, scalability, and accessibility across various sectors. In this essay, we delve into the intricacies of cloud computing, exploring its evolution, functionalities, and profound impact on modern society.Firstly, it is essential to understand the concept of cloud computing. In simple terms, cloud computing refers to the delivery of computing services—including servers, storage, databases, networking, software, and analytics—over the internet ("the cloud"). Instead of owning physical infrastructure or data centers, users can access resources on-demand from cloud service providers on a pay-as-you-go basis. This on-demand availability, coupled with thescalability and flexibility offered by cloud platforms, has revolutionized the way businesses operate and individuals interact with technology.The evolution of cloud computing can be traced back to the early 2000s when companies began exploring ways to outsource IT infrastructure and services to reduce costsand improve efficiency. However, it was not until the mid-2000s that cloud computing gained widespread adoption with the introduction of Amazon Web Services (AWS) in 2006. AWS pioneered the concept of Infrastructure as a Service (IaaS), allowing businesses to rent virtual servers and storage space on a per-hour basis. This marked the beginning of a new era in computing, characterized by the democratizationof IT resources and the rise of cloud-native applications.Since then, cloud computing has continued to evolve,with major players such as Microsoft Azure, Google Cloud Platform, and IBM Cloud entering the market. These cloud providers offer a comprehensive suite of services,including Platform as a Service (PaaS) and Software as a Service (SaaS), enabling developers to build, deploy, andmanage applications without worrying about underlying infrastructure. Moreover, advancements in virtualization, containerization, and serverless computing have further optimized resource utilization and simplified the deployment of complex applications.One of the key advantages of cloud computing is its scalability. Unlike traditional on-premises infrastructure, which requires upfront investment in hardware and software, cloud services allow organizations to scale resources up or down based on demand. This elasticity not only reducescosts but also ensures optimal performance during peakusage periods. Furthermore, cloud computing facilitatesrapid innovation by providing developers with access to cutting-edge tools and technologies, such as artificial intelligence, machine learning, and big data analytics.In addition to scalability and innovation, cloud computing offers enhanced reliability and security. Cloud providers invest heavily in robust infrastructure and employ sophisticated security measures to protect data from unauthorized access, data breaches, and other cyber threats.Furthermore, cloud-based backups and disaster recovery solutions ensure business continuity and mitigate the risk of data loss due to hardware failures or natural disasters.From a societal perspective, cloud computing has democratized access to technology, leveling the playing field for startups, small businesses, and aspiring entrepreneurs. By eliminating the need for substantial upfront investment in IT infrastructure, cloud services enable organizations of all sizes to compete on a global scale. Moreover, the scalability and accessibility of cloud platforms have facilitated the proliferation of remote work and collaboration, particularly in the wake of the COVID-19 pandemic.In conclusion, cloud computing represents a paradigm shift in the way we harness the power of technology. Its evolution from a niche concept to a ubiquitous computing model has transformed industries, empowered individuals, and driven innovation on a global scale. As we continue to embrace the cloud-first mentality, it is imperative torecognize its potential and adapt to the ever-changing landscape of technology.。
写一篇云计算说明的英文作文
写一篇云计算说明的英文作文Cloud computing has become an increasingly prevalent technology in today's digital landscape, revolutionizing the way we store, access, and process data. This innovative approach to computing has transformed the way businesses and individuals operate, offering a plethora of benefits and opportunities. In this essay, we will delve into the intricacies of cloud computing, exploring its fundamental principles, key features, and the remarkable impact it has had on various industries.At its core, cloud computing refers to the delivery of computing services, including storage, processing power, and software, over the internet. Instead of relying on local hardware and infrastructure, cloud computing harnesses the vast resources of remote servers, known as the "cloud," to provide users with on-demand access to a wide range of digital services. This shift away from traditional computing models has ushered in a new era of flexibility, scalability, and cost-efficiency.One of the primary advantages of cloud computing lies in its scalability. Businesses and individuals can easily scale their computing resources up or down based on their changing needs,without the burden of maintaining and upgrading their own hardware. This flexibility allows organizations to respond rapidly to market fluctuations, seasonal demands, or unexpected spikes in usage, ensuring that they can always meet their computing requirements. Additionally, cloud providers often offer a pay-as-you-go pricing model, enabling users to only pay for the resources they actually consume, resulting in significant cost savings.Another key feature of cloud computing is its enhanced accessibility. By storing data and applications in the cloud, users can access their information from anywhere with an internet connection, using a variety of devices such as laptops, smartphones, or tablets. This remote accessibility fosters increased productivity, as employees can collaborate and work seamlessly across multiple locations, eliminating the constraints of traditional office-based work. Furthermore, cloud-based applications and software can be updated and maintained by the service providers, reducing the burden on users and ensuring that they always have access to the latest features and security updates.The impact of cloud computing extends far beyond the realm of individual users and small businesses. Larger enterprises have also embraced this technology, leveraging its capabilities to streamline their operations, enhance data management, and drive innovation. Cloud-based enterprise resource planning (ERP) systems, for instance,enable organizations to integrate and automate various business processes, such as accounting, supply chain management, and human resources, leading to increased efficiency and improved decision-making.Moreover, the rise of cloud computing has paved the way for the development of new technologies and business models. Cloud-based platforms have facilitated the emergence of software-as-a-service (SaaS) models, where users can access and utilize software applications without the need to install and maintain them locally. This shift has led to the proliferation of cloud-based productivity suites, customer relationship management (CRM) tools, and other software solutions that can be accessed and utilized on-demand.In the realm of data storage and management, cloud computing has revolutionized the way organizations handle their information. Cloud-based storage solutions offer virtually limitless capacity, allowing businesses to store and backup their data securely, without the need for physical hardware or on-site infrastructure. This has led to enhanced data resilience, as cloud providers often implement robust backup and disaster recovery measures, ensuring that critical information is protected and readily available.The advancements in cloud computing have also had a significant impact on the field of data analytics and business intelligence.Cloud-based data analytics platforms enable organizations to collect, process, and analyze large volumes of data in real-time, providing valuable insights that can drive informed decision-making and strategic planning. These cloud-based solutions often integrate with a wide range of data sources, allowing for comprehensive and data-driven business intelligence.Furthermore, the cloud computing landscape has given rise to innovative technologies such as edge computing and the Internet of Things (IoT). Edge computing, which involves processing data closer to the source rather than in a centralized cloud, has enabled faster response times and reduced latency for applications that require real-time processing, such as autonomous vehicles and smart city infrastructure. The IoT, which connects a vast network of devices and sensors, has been greatly empowered by cloud computing, enabling the collection, storage, and analysis of vast amounts of data generated by these interconnected devices.Despite the numerous benefits of cloud computing, it is essential to address the potential challenges and concerns associated with this technology. One of the primary concerns is data security and privacy, as cloud-based systems involve storing sensitive information on remote servers. To mitigate these risks, cloud providers have implemented robust security measures, such as encryption, access controls, and comprehensive data backup and disaster recoveryplans. Additionally, compliance with industry-specific regulations and data protection laws has become a critical consideration for organizations adopting cloud computing.Another challenge is the potential for vendor lock-in, where users become heavily dependent on a specific cloud provider, making it difficult to migrate to alternative platforms. To address this issue, the industry has seen the development of multi-cloud and hybrid cloud strategies, which allow organizations to leverage the strengths of multiple cloud providers and maintain a degree of flexibility in their cloud infrastructure.In conclusion, cloud computing has emerged as a transformative technology that has profoundly impacted the way we store, access, and process data. Its scalability, accessibility, and cost-efficiency have made it an increasingly attractive option for businesses and individuals alike. As the cloud computing landscape continues to evolve, we can expect to see further advancements in areas such as edge computing, the Internet of Things, and data analytics, driving innovation and revolutionizing the way we interact with technology. While challenges such as data security and vendor lock-in must be addressed, the benefits of cloud computing make it a pivotal force in shaping the digital future.。
英语作文关于云计算
英语作文关于云计算In the realm of technological advancements, cloud computing has emerged as a pivotal innovation that has revolutionizedthe way we store, access, and manage data. This essay aims to explore the multifaceted impact of cloud computing on modern society, touching upon its benefits, challenges, and future prospects.Introduction:The concept of cloud computing refers to the delivery of on-demand computing services over the internet, from thesimplest email applications to the most complex data analysis. It has become an integral part of our daily lives, from personal use to large-scale business operations.Benefits of Cloud Computing:1. Cost-Effectiveness: One of the most significant advantages of cloud computing is its cost-saving potential. Byeliminating the need for expensive hardware and software, businesses can reduce their IT costs significantly.2. Scalability: Cloud services can be easily scaled up ordown according to the needs of the organization, providing flexibility and adaptability to changing demands.3. Accessibility: Data stored in the cloud can be accessedfrom anywhere with an internet connection, allowing forgreater mobility and collaboration among team members.4. Disaster Recovery: Cloud computing offers robust backupand recovery solutions, ensuring that data is not lost in theevent of a disaster.Challenges of Cloud Computing:1. Security Concerns: With data being stored on remote servers, there are concerns about the security and privacy of sensitive information.2. Dependency on Internet Connectivity: Cloud computing is heavily reliant on a stable and fast internet connection, which can be a limitation in areas with poor connectivity.3. Compliance and Legal Issues: Organizations must ensurethat their cloud service providers comply with local and international laws and regulations regarding data protection.Future Prospects:As technology continues to evolve, the future of cloud computing is expected to bring about even more sophisticated services and solutions. The integration of cloud computing with emerging technologies like artificial intelligence and the Internet of Things (IoT) is likely to unlock new possibilities and further transform various industries.Conclusion:In conclusion, cloud computing has become a cornerstone of modern technological infrastructure. While it presentscertain challenges, its benefits have made it an indispensable tool for individuals and businesses alike. As we look to the future, the continued development and adoption of cloud computing are poised to shape the technological landscape in profound ways.。
云计算英语作文
云计算英语作文Cloud computing has revolutionized the way we access and manage data. It has become an integral part of our dailylives, from personal use to large-scale business operations.In this essay, we will explore the concept of cloud computing, its benefits, and its impact on the modern world.Firstly, cloud computing refers to the delivery of computing services over the internet, which includes storage, processing, and software. It allows users to access these services on-demand, without the need for physical infrastructure. This is particularly beneficial for businesses, as it reduces the need for upfront investment in hardware and software.One of the key advantages of cloud computing is scalability. Companies can easily scale up or down their computing resources according to their needs, which is especiallyuseful during peak times. This flexibility helps businessesto manage costs more effectively and avoid unnecessary expenses.Another significant benefit is the accessibility of data.With cloud computing, data can be accessed from anywhere with an internet connection. This is particularly useful forremote workers or for businesses with multiple locations. It allows for greater collaboration and communication among team members, regardless of their physical location.Security is a common concern with cloud computing, but many providers offer robust security measures to protect data. These measures include encryption, secure access protocols, and regular backups. By choosing a reputable cloud provider, businesses can ensure that their data is well-protected.The impact of cloud computing on the modern world is profound. It has enabled the growth of startups and small businesses by providing them with access to resources that were previously only available to larger companies. It has also transformedthe way we consume media, with streaming services likeNetflix and Spotify relying heavily on cloud infrastructure.In conclusion, cloud computing has become a vital part of our digital landscape. Its benefits, such as scalability, accessibility, and cost-effectiveness, make it an attractive option for businesses and individuals alike. As technology continues to advance, the role of cloud computing is only set to grow, shaping the future of data management and accessibility.。
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云计算——新兴的计算技术摘要：云计算是涉及通过互联网提供托管服务的总称。
这些服务大致分为三类：基础设施即服务（IaaS）、平台即服务（PaaS）和软件即服务（SaaS）。
云计算这个名字的灵感来自于云符号经常用来代表在互联网上流程图和图表。
这是在继主机计算、个人电脑计算、客户端服务器计算和Web计算之后的第五代计算技术。
本文将围绕云计算进行讨论。
关键词：云计算，IaaS（基础设施即服务），PaaS的（平台即服务），SaaS（软件即服务）1引言云服务有三个鲜明的特点区别于传统的主机服务模式，它们分别是：云服务的出售通常按分钟或小时收取费用；云服务是有弹性的，一个用户可以在不同的时间拥有可多可少的服务；云服务完全由供应商托管（消费者只需要通过个人电脑和互联网就可以使用）。
虚拟化的重大创新、分布式计算的发展，以及高速互联网的建设和经济的衰落，都加速了对云计算的兴趣。
云可以是私有的或公有的。
公有云向互联网上的任何人销售（目前，亚马逊的网络服务是最大的公有云服务提供商）。
私有云是一个专有网络或数据中心，向一部分人提供托管服务。
当服务提供商使用公有云资源来创建自己的私有云，这样的结果被称为虚拟化的私有云。
私有云或公共云的云计算目标是提供方便的、可扩展的计算资源和IT服务[1]。
2云计算的优势云计算具有的优势是什么？(a)最小化的资本开支(b)位置和设备独立性答案：供应商的视角：申请厂商更容易吸引新客户。
(a)提供最低成本的方法和配套应用；(b)能够使用商品服务器和存储硬件；3云计算的障碍从客户的视角来看，云计算的障碍有：(a)数据安全；(b)很多客户不希望他们的数据迁移到可以信任的“云”上；(c)数据必须进行本地保留；(d)延迟；(e)云可以走多少毫秒；(f)不是实时应用的理想选择；(g)应用程序可用性；(h)无法通过现有的传统应用进行切换；(i)等效的云应用不存在；总结，并非所有的应用程序都要工作在公共云之上。
4云计算的体系结构云计算架构及其实现的定义非常强调UNIX哲学，具备开发人员必须遵循的一系列规则，确保云计算将很容易地实施，并且保证应用程序对用户的优势。
虽然有很多Unix哲学的定义，规则和原则，他们都有一个共同的信念：建立一个协同工作的事物。
通过UNIX哲学，设计云计算架构的开发商必须记住的是只有一个应用程序并且至少有一个输出。
云计算可能是由不同的阶段组成，但这些阶段是以实现在线申请一致的计算为目标。
数据中心和服务器农场提出了应用程序的需求。
可以说，许多硬件可以被用来支持一个进程，但这些都应该确保该应用程序有足够的后备设备计划。
云计算的应用程序也被认为是由安全性和性能监测组成的。
通过云计算架构的正确执行，应用程序将能够为用户提供7×24小时的服务。
5云计算安全安全是企业的最关注的问题之一。
不管业务有多大，或者有多小，都应该采取必要的安全措施。
不同的安全漏洞通常会引来不同意图的攻击。
一个单一的安全问题可能意味着数百万元的企业，可能会突然就无法正常经营了。
安全措施对于云计算是非常必要的[3]。
从互联网启动的应用程序更容易受到攻击[3]。
局域网的应用程序比部署在外网的应用程序安全性好。
这是云计算的独特情况。
云计算的实现可能需要数百万的资金用于基础设施的建设和应用程序的开发，但仍置于不同类型的攻击之中。
5.1保护用户除了以上的问题之外，云计算或者任何网络形式的应用程序都应该考虑保护其用户。
开发者应该保证用户相关的数据不会被错误的获取。
这里有两种方案保证云计算的安全：限制用户的访问和认证。
(a)限制性访问可能来自简单的用户名和密码，但是云计算的应用程序不仅应立足于这些挑战。
IP的特定应用和用户访问的时间只是云计算安全应予以执行的一些措施。
限制用户访问的挑战在于限制用户的访问权限。
每个用户必须手动指派安全检查，以确保限制通行不同的文件。
(b)证书对于用户的认证也同样重要。
开发商必须开放其提供安全认证的专家或公司。
这是一种被不同类型的攻击测试用户的方式。
这常常是云计算外部安全检查面对的可以公开公司秘密的难题，但是这必须以确保其用户的安全为前提。
5.2数据安全除了对用户受到不同类型攻击的保护，数据本身应该得到保护。
在这方面，硬件与软件都会起到作用。
而且，认证在数据安全方面是非常必要的。
另一方面，计算机硬件需要不同类型的安全考虑。
数据中心的位置选择不仅要考虑是否靠近控制器和用户，而且还需要考虑其外部安全问题（甚至是保密）。
数据中心应该得到保护，可以适应不同类型的天气条件，能够抵御会造成物理损坏的火灾等自然灾害。
对于添置应用程序有关的硬件，某些硬件必须增加安全性。
其中之一是手动关机，以防止信息的进一步访问。
虽然数据可以由其他应用程序控制，但是数据也会流失除非立即关机。
5.3恢复和调查云计算安全不应只注重预防本身。
充足的资源，也应侧重于恢复，如果真的发生不幸就会罢工。
即使在灾难发生时，某些计划必须到位，以确保每个应用都能复苏。
该计划并不一定要把重点放在单独攻击的软件上，如某些外部灾害天气情况应该有单独的恢复计划。
当一切都已经恢复，供应商及受理申请的公司应通过一些途径调查问题的原因。
通过调查，可以发现该事件导致的原因，甚至采取法律的行动，如果安全受到故意破坏。
实施云计算，安全是最困难的任务之一。
它不仅要求能够从软件方面抵御各种形式的攻击，而且在硬件方面也要能够起到作用。
攻击造成灾难性的影响只需要一个安全漏洞，所以它始终是每个人面临的安全性挑战。
6云计算的挑战云计算应用的挑战主要在于应用程序可以处理的请求数量[2]。
尽管这个问题有了数据中心的建议，没有正确开发阿杜应用程序也会遇到门槛。
为了解决这一问题，开发者使的元数据来为用户提供个性化的服务，以及数据处理。
通过元数据，个性化的要求将被接纳，并会得到妥善落实。
元数据还保证在正常运行时间的交易数据请求将会得到延缓如果开发商选择这样做。
7云计算的未来云计算可能是一些企业和消费者比较新的概念。
但是即使一些企业刚开始采用，也能获益于云计算的优势。
很多行业巨头都已经开始期待着下一个云计算阶段。
云计算的未来应高度考虑在任何行业的企业。
云计算的能够完全适应任何一个行业的可能性正在慢慢开始出现。
如果一个企业不考虑在云计算时代的未来，面临的挑战以及云计算的优势可能无法得到合理和充分利用。
Cloud C omputing-The Emerging Technology of C omputingPratima Manhas,Shaveta ThakralECE Dept,Manav Rachna International,University(MRIU),Faridabad,IndiaABSTRACT：Cloud computing is a general term for anything that involves delivering hosted services over the Internet.These services are broadly divided into three categories:Infrastructure-as-a-Service(IaaS), Platform-as-a-Service(PaaS)and Software-as-a-Service(SaaS).The name cloud computing was inspired by the cloud symbol that's often used to represent the Internet in flowcharts and diagrams.It is the5th generation of computing after mainframe,personal computer,client server computing and the web.In this certain application,limitation and future scope of this technology was discussed.KEY WORDS:Cloud computing,IaaS(Infrastructure-as-a-Service),PaaS(Platform-as-a-Service),SaaS (Software-as-a-Service)1IntroductionA cloud service has three distinct characteristics that differentiate it from traditional hosting.It is sold on demand,typically by the minute or the hour;it is elastic--a user can have as much or as little of a service as they want at any given time;and the service is fully managed by the provider(the consumer needs nothing but a personal computer and Internet access).Significant innovations in virtualization and distributed computing,as well as improved access to high-speed Internet and a weak economy,have accelerated interest in cloud computing.A cloud can be private or public.A public cloud sells services to anyone on the Internet.(Currently, Amazon Web Services is the largest public cloud provider.)A private cloud is a proprietary network or a data center that supplies hosted services to a limited number of people.When a service provider uses public cloud resources to create their private cloud,the result is called a virtual private cloud.Private or public,the goal of cloud computing is to provide easy,scalable access to computing resources and IT services[1].Infrastructure-as-a-Service like Amazon Web Services provides virtual server instances with unique IP addresses and blocks of storage on demand.Customers use the provider's application program interface(API) to start,stop,access and configure their virtual servers and storage.In the enterprise,cloud computing allows a company to pay for only as much capacity as is needed,and bring more online as soon as required.Platform-as-a-service in the cloud is defined as a set of software and product development tools hosted on the provider's infrastructure.Developers create applications on the provider's platform over the Internet. PaaS providers may use APIs,website portals or gateway software installed on the customer's computer. ,(an outgrowth of )and Google Apps are examples of PaaS.Developers need to know that currently,there are not standards for interoperability or data portability in the cloud.Some providers will not allow software created by their customers to be moved off the provider's platform.In the software-as-a-service cloud model,the vendor supplies the hardware infrastructure,the software product and interacts with the user through a front-end portal.SaaS is a very broad market.Services can beanything from Web-based email to inventory control and database processing.Because the service provider hosts both the application and the data,the end user is free to use the service from anywhere.2Benefits of Cloud Computing(a)Minimized Capital expenditure(b)Location and Device independence(c)Utilization and efficiency improvement(d)Very high Scalability(e)High Computing powerA.VendorPerspectiveEasier for application vendors to reach new customers(a)Lowest cost way of delivering and supporting applications(b)Ability to use commodity server and storage hardware(c)Ability to drive down data center operational cots(d)In one word:economics3Barriers to Cloud ComputingA.Customer Perspective(a)Data Security(b)Many customers don’t wish to trust their data to“the cloud”(c)Data must be locally retained for regulatory reasons(d)Latency(e)The cloud can be many milliseconds away(f)Not suitable for real-time applications(g)Application Availability(h)Cannot switch from existing legacy applications(i)Equivalent cloud applications do not existNot all applications work on public clouds4Architecture of cloud computingCloud computing architecture and its implementation is strongly defined by the Unix Philosophy.It’s basically a set of rules and principles that developers would have to follow to ensure that cloud computing would be easily implemented and the application would be for the advantage of the user.Although there are many definitions,rules and principles for Unix Philosophy,they all point out to one belief:build one thing and make sure it works consistently.Through the Unix Philosophy,developers who design the architecture for cloud computing have to remember that they there only to support only one application or at least an output. Cloud computing could be composed of different stages but these stages are geared towards the consistent computing of the online application.Keeping up with the demands of the application is the data centers and server farms.It could be said that too much hardware could be used to support a single process but these are implemented to ensure that theapplication would have as many back-up plans as it could have.Applications from cloud computing is also implemented with the thought of consistent security and performance monitoring.Through proper implementation of cloud computing architecture,the application will be accessible24/7with a new100% uptime for their users.5Security on cloud computingSecurity is one of the biggest concerns of businesses in any form.Whether a business is a small brick-and-mortar or a multi-million online ventures,security should be implemented.Exposing the company to different security flaws is always inviting to different elements with malicious intent.A single security strike could mean millions of dollars for businesses and might single handedly close the business down.Proper implementation of security measures is highly recommended for cloud computing[3].The mere fact that the application is launched through internet makes it vulnerable to any time of attack[3].An application available in LAN(Local Area Network)only could even be infiltrated from the outside so placing an application over the internet is always a security risk.This is the unique situation of cloud computing. Implementation of cloud computing could require millions of dollars in infrastructure and applications development but it still places itself at risk for different types of attacks.A.Protecting the UsersAbove everything else,cloud computing or any type of online application format should consider protecting its users.Developers should make sure that data related to the user should not be mishandled and could be extracted just by one.There are two ways to ensure cloud computing security:restrictive user access and certifications.(i)Restrictive access could come from simple username/password challenge to complicated CAPTCHA log in forms.But applications in cloud computing should not only base itself on these challenges.IP specific applications and user time-outs are only some of the security measures that should be implemented.The challenge in restrictive user access is to limit the access privilege of the user.Each user will have to be assigned manually with security clearance to ensure limitation of access to different files.(ii)Certifications are also important for user certification.Developers have to open their application to security specialists or companies that provide certifications for security.This is one way of assuring users that the application has been fully tested against different types of attacks.This is often the dilemma for cloud computing as external security checks might open the company secrets on cloud computing.But this has to be sacrificed to ensure the security of their users.B.Data SecurityAside from user protection against different types of attacks,the data itself should be protected.In this aspect,the hardware and software linked to cloud computing should be scrutinized.Again,a certification is highly desired in this part of cloud computing.The hardware component for cloud computing on the other hand requires a different type of security consideration.The location of data center should not only be selected because of its proximity to controllers and intended users but also on its security(and even secrecy)from external problems.The data center should be protected against different types of weather conditions,fire and even physical attacks that might destroy the center physically.With regards to the hardware component in relation to the application,certain manual components have to be available for increased security.Among them is manual shutdown to prevent further access of the information.Although data could be controlled with another application that data could be infiltrated unless the application is shutdown immediately.C.Recovery and InvestigationCloud computing security should not only focus itself on prevention.Ample resources should also be focused on recovery if the unfortunate event really strikes.Even before disaster happens,certain plans have to be in place to ensure that everyone will be working in unison towards recovery.The plans do not have to be focused on software attacks alone–certain external disasters such as weather conditions should have separate recovery plans.When everything has been recovered,developers and the company handling the application should have the means to investigate the cause of the problem.Through investigation,certain conditions that lead to the event could be realized and insecurities could be discovered.Even legal actions could be done if security has been breached on purpose.Security is one of the most difficult task to implement in cloud computing.It requires constant vigilance against different forms of attacks not only in the application side but also in the hardware components.Attacks with catastrophic effects only needs one security flaw so it’s always a challenge for everyone involved to make things secured.6Challenges in cloud computingThe challenge for applications in cloud computing is largely based on the number of requests the application could handle[2].Although this factor could be highly suggested by the data center,the application will usually have a threshold if they are not properly written.To deal with this concern,developers use metadata to enable personalized services to their users as well as data processing.Through metadata,individualized requests will be entertained and will be properly implemented.Metadata also ensures uptime of transaction as data requests will be slowed down if the developer chooses to do so.7Future of cloud computingCloud computing may be a relatively new concept for some businesses and consumers.But even though some businesses are only starting to adopt and realizing the advantages of cloud computing,industry giants are already looking forward to the next big step of cloud computing.The future of cloud computing should be highly considered by businesses in any industry.The possibility of full adaptation of cloud computing by almost any industry is slowly starting to happen.If a business will not consider their future in cloud computing,the challenges as well as the advantages of cloud computing may not be addressed and fully harnessed.References[1]Toby Velte,Anthony Velte,Robert Elsenpeter.“Cloud Computing,A Practical Approach”,Mcgraw-Hill Education,2009.[2]Ronald Krutz and Russell Vines.“Cloud Security:A Comprehensive Guide to Secure Cloud Computing”, Wiley Publishing Inc,2010.[3]John Rittenhouse and James Ransome.“Cloud Computing:Implementation,Management,and Security”, CRC Press2010.。