Conference on Computer and Communications Security : proceedings of the ... conference on computer and communications security. ACM Conference on Computer and Communications Security最新文献
We propose a new and efficient scheme for broadcast encryption. A broadcast encryption system allows a broadcaster to send an encrypted message to a dynamically chosen subset RS, |RS|=n of a given set of users, such that only users in this subset can decrypt the message. An important component of broadcast encryption schemes is revocation of users by the broadcaster, thereby updating the subset RS. Revocation may be either temporary, for a specific ciphertext, or permanent. We present the first public key broadcast encryption scheme that support permanent revocation of users. Our scheme is fully collusion resistant. In other words, even if all the users in the network collude with a revoked user, the revoked user cannot encrypt messages without receiving new keys from the broadcaster. The procedure is based on Cipher-text Policy Attribute-Based Encryption (CP-ABE). The overhead of our system is O(log n) in all major performance measures including length of private and public keys, computational complexity, user's storage space, and computational complexity of encryption and decryption.
{"title":"Poster: attribute based broadcast encryption with permanent revocation","authors":"S. Dolev, N. Gilboa, M. Kopeetsky","doi":"10.1145/2046707.2093486","DOIUrl":"https://doi.org/10.1145/2046707.2093486","url":null,"abstract":"We propose a new and efficient scheme for broadcast encryption. A broadcast encryption system allows a broadcaster to send an encrypted message to a dynamically chosen subset RS, |RS|=n of a given set of users, such that only users in this subset can decrypt the message. An important component of broadcast encryption schemes is revocation of users by the broadcaster, thereby updating the subset RS. Revocation may be either temporary, for a specific ciphertext, or permanent. We present the first public key broadcast encryption scheme that support permanent revocation of users. Our scheme is fully collusion resistant. In other words, even if all the users in the network collude with a revoked user, the revoked user cannot encrypt messages without receiving new keys from the broadcaster. The procedure is based on Cipher-text Policy Attribute-Based Encryption (CP-ABE).\u0000 The overhead of our system is O(log n) in all major performance measures including length of private and public keys, computational complexity, user's storage space, and computational complexity of encryption and decryption.","PeriodicalId":72687,"journal":{"name":"Conference on Computer and Communications Security : proceedings of the ... conference on computer and communications security. ACM Conference on Computer and Communications Security","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2011-10-17","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"77600666","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
A. Moradi, Alessandro Barenghi, Timo Kasper, C. Paar
Over the last two decades FPGAs have become central components for many advanced digital systems, e.g., video signal processing, network routers, data acquisition and military systems. In order to protect the intellectual property and to prevent fraud, e.g., by cloning a design embedded into an FPGA or manipulating its content, many current FPGAs employ a bitstream encryption feature. We develop a successful attack on the bitstream encryption engine integrated in the widespread Virtex-II Pro FPGAs from Xilinx, using side-channel analysis. After measuring the power consumption of a single power-up of the device and a modest amount of off-line computation, we are able to recover all three different keys used by its triple DES module. Our method allows extracting secret keys from any real-world device where the bitstream encryption feature of Virtex-II Pro is enabled. As a consequence, the target product can be cloned and manipulated at the will of the attacker since no side-channel protection was included into the design of the decryption module. Also, more advanced attacks such as reverse engineering or the introduction of hardware Trojans become potential threats. While performing the side-channel attack, we were able to deduce a hypothetical architecture of the hardware encryption engine. To our knowledge, this is the first attack against the bitstream encryption of a commercial FPGA reported in the open literature.
在过去的二十年中，fpga已经成为许多先进数字系统的核心部件，例如视频信号处理、网络路由器、数据采集和军事系统。为了保护知识产权和防止欺诈，例如，通过克隆嵌入FPGA的设计或操纵其内容，许多当前的FPGA采用比特流加密功能。我们开发了一个成功的攻击比特流加密引擎集成在广泛的Virtex-II Pro fpga从Xilinx，使用侧信道分析。在测量了设备单次上电的功耗和适度的离线计算之后，我们能够恢复其三重DES模块使用的所有三个不同的密钥。我们的方法允许从启用Virtex-II Pro的比特流加密功能的任何现实世界设备中提取密钥。因此，由于解密模块的设计中没有包含侧信道保护，攻击者可以随意克隆和操纵目标产品。此外，更高级的攻击，如逆向工程或引入硬件木马，也会成为潜在的威胁。在执行侧信道攻击时，我们能够推断出硬件加密引擎的假设架构。据我们所知，这是公开文献中报道的针对商用FPGA的比特流加密的第一次攻击。
{"title":"On the vulnerability of FPGA bitstream encryption against power analysis attacks: extracting keys from xilinx Virtex-II FPGAs","authors":"A. Moradi, Alessandro Barenghi, Timo Kasper, C. Paar","doi":"10.1145/2046707.2046722","DOIUrl":"https://doi.org/10.1145/2046707.2046722","url":null,"abstract":"Over the last two decades FPGAs have become central components for many advanced digital systems, e.g., video signal processing, network routers, data acquisition and military systems. In order to protect the intellectual property and to prevent fraud, e.g., by cloning a design embedded into an FPGA or manipulating its content, many current FPGAs employ a bitstream encryption feature. We develop a successful attack on the bitstream encryption engine integrated in the widespread Virtex-II Pro FPGAs from Xilinx, using side-channel analysis. After measuring the power consumption of a single power-up of the device and a modest amount of off-line computation, we are able to recover all three different keys used by its triple DES module. Our method allows extracting secret keys from any real-world device where the bitstream encryption feature of Virtex-II Pro is enabled. As a consequence, the target product can be cloned and manipulated at the will of the attacker since no side-channel protection was included into the design of the decryption module. Also, more advanced attacks such as reverse engineering or the introduction of hardware Trojans become potential threats. While performing the side-channel attack, we were able to deduce a hypothetical architecture of the hardware encryption engine. To our knowledge, this is the first attack against the bitstream encryption of a commercial FPGA reported in the open literature.","PeriodicalId":72687,"journal":{"name":"Conference on Computer and Communications Security : proceedings of the ... conference on computer and communications security. ACM Conference on Computer and Communications Security","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2011-10-17","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"83676465","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Mouse dynamics is the process of verifying the identity of computer users on the basis of their mouse operating characteristics, which are derived from the movement and click events. Some researchers have explored this domain and reported encouraging results, but few focused on applicability in a realistic setting. Specifically, many of the existing approaches require an impractically long verification time to achieve a reasonable accuracy. In this work, we investigate the mouse dynamics of 26 subjects under a tightly-controlled environment. Using procedural features such as speed and acceleration curves to more accurately characterize mouse activity, and adopting distance metrics to overcome the within-class variability, we achieved a promising performance with a false-acceptance rate of 8.87%, a false-rejection rate of 7.16%, and an average verification time of 11.8 seconds. We find that while this level of accuracy comes close to meeting the requirements of identity verification, a tradeoff must be made between security and user acceptability. We also suggest opportunities for further investigation through additional, controlled experimental environments.
{"title":"Poster: can it be more practical?: improving mouse dynamics biometric performance","authors":"Chao Shen, Zhongmin Cai, X. Guan","doi":"10.1145/2046707.2093510","DOIUrl":"https://doi.org/10.1145/2046707.2093510","url":null,"abstract":"Mouse dynamics is the process of verifying the identity of computer users on the basis of their mouse operating characteristics, which are derived from the movement and click events. Some researchers have explored this domain and reported encouraging results, but few focused on applicability in a realistic setting. Specifically, many of the existing approaches require an impractically long verification time to achieve a reasonable accuracy. In this work, we investigate the mouse dynamics of 26 subjects under a tightly-controlled environment. Using procedural features such as speed and acceleration curves to more accurately characterize mouse activity, and adopting distance metrics to overcome the within-class variability, we achieved a promising performance with a false-acceptance rate of 8.87%, a false-rejection rate of 7.16%, and an average verification time of 11.8 seconds. We find that while this level of accuracy comes close to meeting the requirements of identity verification, a tradeoff must be made between security and user acceptability. We also suggest opportunities for further investigation through additional, controlled experimental environments.","PeriodicalId":72687,"journal":{"name":"Conference on Computer and Communications Security : proceedings of the ... conference on computer and communications security. ACM Conference on Computer and Communications Security","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2011-10-17","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"85382938","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
A. Felt, Erika Chin, Steve Hanna, D. Song, D. Wagner
Android provides third-party applications with an extensive API that includes access to phone hardware, settings, and user data. Access to privacy- and security-relevant parts of the API is controlled with an install-time application permission system. We study Android applications to determine whether Android developers follow least privilege with their permission requests. We built Stowaway, a tool that detects overprivilege in compiled Android applications. Stowaway determines the set of API calls that an application uses and then maps those API calls to permissions. We used automated testing tools on the Android API in order to build the permission map that is necessary for detecting overprivilege. We apply Stowaway to a set of 940 applications and find that about one-third are overprivileged. We investigate the causes of overprivilege and find evidence that developers are trying to follow least privilege but sometimes fail due to insufficient API documentation.
{"title":"Android permissions demystified","authors":"A. Felt, Erika Chin, Steve Hanna, D. Song, D. Wagner","doi":"10.1145/2046707.2046779","DOIUrl":"https://doi.org/10.1145/2046707.2046779","url":null,"abstract":"Android provides third-party applications with an extensive API that includes access to phone hardware, settings, and user data. Access to privacy- and security-relevant parts of the API is controlled with an install-time application permission system. We study Android applications to determine whether Android developers follow least privilege with their permission requests. We built Stowaway, a tool that detects overprivilege in compiled Android applications. Stowaway determines the set of API calls that an application uses and then maps those API calls to permissions. We used automated testing tools on the Android API in order to build the permission map that is necessary for detecting overprivilege. We apply Stowaway to a set of 940 applications and find that about one-third are overprivileged. We investigate the causes of overprivilege and find evidence that developers are trying to follow least privilege but sometimes fail due to insufficient API documentation.","PeriodicalId":72687,"journal":{"name":"Conference on Computer and Communications Security : proceedings of the ... conference on computer and communications security. ACM Conference on Computer and Communications Security","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2011-10-17","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"79826902","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Biometric authentication verifies a user based on its inherent, unique characteristics --- who you are. In addition to physiological biometrics, behavioral biometrics has proven very useful in authenticating a user. Mouse dynamics, with their unique patterns of mouse movements, is one such behavioral biometric. In this paper, we present a user verification system using mouse dynamics, which is both accurate and efficient enough for future usage. The key feature of our system lies in using much more fine-grained (point-by-point) angle-based metrics of mouse movements for user verification. These new metrics are relatively unique from person to person and independent of the computing platform. Moreover, we utilize support vector machines (SVMs) for accurate and fast classification. Our technique is robust across different operating platforms, and no specialized hardware is required. The efficacy of our approach is validated through a series of experiments. Our experimental results show that the proposed system can verify a user in an accurate and timely manner, and induced system overhead is minor.
{"title":"An efficient user verification system via mouse movements","authors":"Nan Zheng, Aaron Paloski, Haining Wang","doi":"10.1145/2046707.2046725","DOIUrl":"https://doi.org/10.1145/2046707.2046725","url":null,"abstract":"Biometric authentication verifies a user based on its inherent, unique characteristics --- who you are. In addition to physiological biometrics, behavioral biometrics has proven very useful in authenticating a user. Mouse dynamics, with their unique patterns of mouse movements, is one such behavioral biometric. In this paper, we present a user verification system using mouse dynamics, which is both accurate and efficient enough for future usage. The key feature of our system lies in using much more fine-grained (point-by-point) angle-based metrics of mouse movements for user verification. These new metrics are relatively unique from person to person and independent of the computing platform. Moreover, we utilize support vector machines (SVMs) for accurate and fast classification. Our technique is robust across different operating platforms, and no specialized hardware is required. The efficacy of our approach is validated through a series of experiments. Our experimental results show that the proposed system can verify a user in an accurate and timely manner, and induced system overhead is minor.","PeriodicalId":72687,"journal":{"name":"Conference on Computer and Communications Security : proceedings of the ... conference on computer and communications security. ACM Conference on Computer and Communications Security","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2011-10-17","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"80373859","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Software suffers from security vulnerabilities and to our best knowledge, no silver bullet exists to make all the software absolutely secure. Network software applications, e.g. network servers, due to historic reasons, often have a monolithic architecture. Therefore, the whole application stays in a single protection domain, and any vulnerability of any part would jeopardize the whole application. The principle of least privilege provides an alternative way to design and implement software with better security. uPro is a software compartmentalization tool supporting fine-grained and flexible configuration. The configuration is provided by the developers and it specifies the protection domain partition of the software application and the corresponding privilege of each partition. The configuration file is simple and extensible. Based on the configuration file, uPro loads all the protection domains to a single address space and locates all the protection domains to non-interleaved memory regions. The protection domain separation is achieved at the user level so that uPro is totally OS-neutral. uPro supports concurrent execution. The execution units and the protection domains are orthogonal and their implementation is based on threads, so the context-switch time of the execution units in uPro is lightweight compared to process implementation.
{"title":"Poster: uPro: a compartmentalization tool supporting fine-grained and flexible security configuration","authors":"Ben Niu, Gang Tan","doi":"10.1145/2046707.2093504","DOIUrl":"https://doi.org/10.1145/2046707.2093504","url":null,"abstract":"Software suffers from security vulnerabilities and to our best knowledge, no silver bullet exists to make all the software absolutely secure. Network software applications, e.g. network servers, due to historic reasons, often have a monolithic architecture. Therefore, the whole application stays in a single protection domain, and any vulnerability of any part would jeopardize the whole application. The principle of least privilege provides an alternative way to design and implement software with better security. uPro is a software compartmentalization tool supporting fine-grained and flexible configuration. The configuration is provided by the developers and it specifies the protection domain partition of the software application and the corresponding privilege of each partition. The configuration file is simple and extensible. Based on the configuration file, uPro loads all the protection domains to a single address space and locates all the protection domains to non-interleaved memory regions. The protection domain separation is achieved at the user level so that uPro is totally OS-neutral. uPro supports concurrent execution. The execution units and the protection domains are orthogonal and their implementation is based on threads, so the context-switch time of the execution units in uPro is lightweight compared to process implementation.","PeriodicalId":72687,"journal":{"name":"Conference on Computer and Communications Security : proceedings of the ... conference on computer and communications security. ACM Conference on Computer and Communications Security","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2011-10-17","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"87300603","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
The complexity of modern web applications makes it difficult for developers to fully understand the security implications of their code. Attackers exploit the resulting security vulnerabilities to gain unauthorized access to the web application environment. Previous research into web application vulnerabilities has mostly focused on input validation flaws, such as cross site scripting and SQL injection, while logic flaws have received comparably less attention. In this paper, we present a comprehensive study of a relatively unknown logic flaw in web applications, which we call Execution After Redirect, or EAR. A web application developer can introduce an EAR by calling a redirect method under the assumption that execution will halt. A vulnerability occurs when server-side execution continues after the developer's intended halting point, which can lead to broken/insufficient access controls and information leakage. We start with an analysis of how susceptible applications written in nine web frameworks are to EAR vulnerabilities. We then discuss the results from the EAR challenge contained within the 2010 International Capture the Flag Competition. Finally, we present an open-source, white-box, static analysis tool to detect EARs in Ruby on Rails web applications. This tool found 3,944 EAR instances in 18,127 open-source applications. Finally, we describe an approach to prevent EARs in web frameworks.
现代web应用程序的复杂性使得开发人员很难完全理解其代码的安全含义。攻击者利用由此产生的安全漏洞获得对web应用程序环境的未经授权的访问。以前对web应用程序漏洞的研究主要集中在输入验证缺陷上，如跨站脚本和SQL注入，而逻辑缺陷受到的关注相对较少。在本文中，我们对web应用程序中一个相对未知的逻辑缺陷进行了全面的研究，我们称之为重定向后执行(EAR)。web应用程序开发人员可以在假设执行将停止的情况下，通过调用重定向方法引入EAR。当服务器端执行在开发人员预期的停止点之后继续执行时，就会出现漏洞，这可能导致访问控制失效/不充分和信息泄漏。我们首先分析了在9个web框架中编写的应用程序对EAR漏洞的影响程度。然后我们讨论了2010年国际夺旗比赛中包含的EAR挑战的结果。最后，我们提出了一个开源的白盒静态分析工具，用于检测Ruby on Rails web应用程序中的ear。该工具在18,127个开源应用程序中发现了3,944个EAR实例。最后，我们描述了一种在web框架中防止ear的方法。
{"title":"Fear the EAR: discovering and mitigating execution after redirect vulnerabilities","authors":"Adam Doupé, B. Boe, Christopher Krügel, G. Vigna","doi":"10.1145/2046707.2046736","DOIUrl":"https://doi.org/10.1145/2046707.2046736","url":null,"abstract":"The complexity of modern web applications makes it difficult for developers to fully understand the security implications of their code. Attackers exploit the resulting security vulnerabilities to gain unauthorized access to the web application environment. Previous research into web application vulnerabilities has mostly focused on input validation flaws, such as cross site scripting and SQL injection, while logic flaws have received comparably less attention. In this paper, we present a comprehensive study of a relatively unknown logic flaw in web applications, which we call Execution After Redirect, or EAR. A web application developer can introduce an EAR by calling a redirect method under the assumption that execution will halt. A vulnerability occurs when server-side execution continues after the developer's intended halting point, which can lead to broken/insufficient access controls and information leakage. We start with an analysis of how susceptible applications written in nine web frameworks are to EAR vulnerabilities. We then discuss the results from the EAR challenge contained within the 2010 International Capture the Flag Competition. Finally, we present an open-source, white-box, static analysis tool to detect EARs in Ruby on Rails web applications. This tool found 3,944 EAR instances in 18,127 open-source applications. Finally, we describe an approach to prevent EARs in web frameworks.","PeriodicalId":72687,"journal":{"name":"Conference on Computer and Communications Security : proceedings of the ... conference on computer and communications security. ACM Conference on Computer and Communications Security","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2011-10-17","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"87389663","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Cloud computing is quickly becoming the platform of choice for many web services. Virtualization is the key underlying technology enabling cloud providers to host services for a large number of customers. Unfortunately, virtualization software is large, complex, and has a considerable attack surface. As such, it is prone to bugs and vulnerabilities that a malicious virtual machine (VM) can exploit to attack or obstruct other VMs -- a major concern for organizations wishing to move to the cloud. In contrast to previous work on hardening or minimizing the virtualization software, we eliminate the hypervisor attack surface by enabling the guest VMs to run natively on the underlying hardware while maintaining the ability to run multiple VMs concurrently. Our NoHype system embodies four key ideas: (i) pre-allocation of processor cores and memory resources, (ii) use of virtualized I/O devices, (iii) minor modifications to the guest OS to perform all system discovery during bootup, and (iv) avoiding indirection by bringing the guest virtual machine in more direct contact with the underlying hardware. Hence, no hypervisor is needed to allocate resources dynamically, emulate I/O devices, support system discovery after bootup, or map interrupts and other identifiers. NoHype capitalizes on the unique use model in cloud computing, where customers specify resource requirements ahead of time and providers offer a suite of guest OS kernels. Our system supports multiple tenants and capabilities commonly found in hosted cloud infrastructures. Our prototype utilizes Xen 4.0 to prepare the environment for guest VMs, and a slightly modified version of Linux 2.6 for the guest OS. Our evaluation with both SPEC and Apache benchmarks shows a roughly 1% performance gain when running applications on NoHype compared to running them on top of Xen 4.0. Our security analysis shows that, while there are some minor limitations with cur- rent commodity hardware, NoHype is a significant advance in the security of cloud computing.
{"title":"Eliminating the hypervisor attack surface for a more secure cloud","authors":"Jakub Szefer, Eric Keller, R. Lee, J. Rexford","doi":"10.1145/2046707.2046754","DOIUrl":"https://doi.org/10.1145/2046707.2046754","url":null,"abstract":"Cloud computing is quickly becoming the platform of choice for many web services. Virtualization is the key underlying technology enabling cloud providers to host services for a large number of customers. Unfortunately, virtualization software is large, complex, and has a considerable attack surface. As such, it is prone to bugs and vulnerabilities that a malicious virtual machine (VM) can exploit to attack or obstruct other VMs -- a major concern for organizations wishing to move to the cloud. In contrast to previous work on hardening or minimizing the virtualization software, we eliminate the hypervisor attack surface by enabling the guest VMs to run natively on the underlying hardware while maintaining the ability to run multiple VMs concurrently. Our NoHype system embodies four key ideas: (i) pre-allocation of processor cores and memory resources, (ii) use of virtualized I/O devices, (iii) minor modifications to the guest OS to perform all system discovery during bootup, and (iv) avoiding indirection by bringing the guest virtual machine in more direct contact with the underlying hardware. Hence, no hypervisor is needed to allocate resources dynamically, emulate I/O devices, support system discovery after bootup, or map interrupts and other identifiers. NoHype capitalizes on the unique use model in cloud computing, where customers specify resource requirements ahead of time and providers offer a suite of guest OS kernels. Our system supports multiple tenants and capabilities commonly found in hosted cloud infrastructures. Our prototype utilizes Xen 4.0 to prepare the environment for guest VMs, and a slightly modified version of Linux 2.6 for the guest OS. Our evaluation with both SPEC and Apache benchmarks shows a roughly 1% performance gain when running applications on NoHype compared to running them on top of Xen 4.0. Our security analysis shows that, while there are some minor limitations with cur- rent commodity hardware, NoHype is a significant advance in the security of cloud computing.","PeriodicalId":72687,"journal":{"name":"Conference on Computer and Communications Security : proceedings of the ... conference on computer and communications security. ACM Conference on Computer and Communications Security","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2011-10-17","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"90032501","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
C. Brzuska, M. Fischlin, B. Warinschi, S. C. Williams
In this paper we examine composability properties for the fundamental task of key exchange. Roughly speaking, we show that key exchange protocols secure in the prevalent model of Bellare and Rogaway can be composed with arbitrary protocols that require symmetrically distributed keys. This composition theorem holds if the key exchange protocol satisfies an additional technical requirement that our analysis brings to light: it should be possible to determine which sessions derive equal keys given only the publicly available information. What distinguishes our results from virtually all existing work is that we do not rely, neither directly nor indirectly, on the simulation paradigm. Instead, our security notions and composition theorems exclusively use a game-based formalism.We thus avoid several undesirable consequences of simulation-based security notions and support applicability to a broader class of protocols. In particular, we offer an abstract formalization of game-based security that should be of independent interest in other investigations using game-based formalisms.
{"title":"Composability of bellare-rogaway key exchange protocols","authors":"C. Brzuska, M. Fischlin, B. Warinschi, S. C. Williams","doi":"10.1145/2046707.2046716","DOIUrl":"https://doi.org/10.1145/2046707.2046716","url":null,"abstract":"In this paper we examine composability properties for the fundamental task of key exchange. Roughly speaking, we show that key exchange protocols secure in the prevalent model of Bellare and Rogaway can be composed with arbitrary protocols that require symmetrically distributed keys. This composition theorem holds if the key exchange protocol satisfies an additional technical requirement that our analysis brings to light: it should be possible to determine which sessions derive equal keys given only the publicly available information. What distinguishes our results from virtually all existing work is that we do not rely, neither directly nor indirectly, on the simulation paradigm. Instead, our security notions and composition theorems exclusively use a game-based formalism.We thus avoid several undesirable consequences of simulation-based security notions and support applicability to a broader class of protocols. In particular, we offer an abstract formalization of game-based security that should be of independent interest in other investigations using game-based formalisms.","PeriodicalId":72687,"journal":{"name":"Conference on Computer and Communications Security : proceedings of the ... conference on computer and communications security. ACM Conference on Computer and Communications Security","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2011-10-17","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"82964237","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Browser designers create security mechanisms to help web developers protect web applications, but web developers are usually slow to use these features in web-based applications (web apps). In this paper we introduce Zan, a browser-based system for applying new browser security mechanisms to legacy web apps automatically. Our key insight is that web apps often contain enough information, via web developer source-code patterns or key properties of web-app objects, to allow the browser to infer opportunities for applying new security mechanisms to existing web apps. We apply this new concept to protect authentication cookies, prevent web apps from being framed unwittingly, and perform JavaScript object deserialization safely. We evaluate Zan on up to the 1000 most popular websites for each of the three cases. We find that Zan can provide complimentary protection for the majority of potentially applicable websites automatically without requiring additional code from the web developers and with negligible incompatibility impact.
{"title":"Fortifying web-based applications automatically","authors":"Shuo Tang, Nathan Dautenhahn, Samuel T. King","doi":"10.1145/2046707.2046777","DOIUrl":"https://doi.org/10.1145/2046707.2046777","url":null,"abstract":"Browser designers create security mechanisms to help web developers protect web applications, but web developers are usually slow to use these features in web-based applications (web apps). In this paper we introduce Zan, a browser-based system for applying new browser security mechanisms to legacy web apps automatically. Our key insight is that web apps often contain enough information, via web developer source-code patterns or key properties of web-app objects, to allow the browser to infer opportunities for applying new security mechanisms to existing web apps. We apply this new concept to protect authentication cookies, prevent web apps from being framed unwittingly, and perform JavaScript object deserialization safely. We evaluate Zan on up to the 1000 most popular websites for each of the three cases. We find that Zan can provide complimentary protection for the majority of potentially applicable websites automatically without requiring additional code from the web developers and with negligible incompatibility impact.","PeriodicalId":72687,"journal":{"name":"Conference on Computer and Communications Security : proceedings of the ... conference on computer and communications security. ACM Conference on Computer and Communications Security","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2011-10-17","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"82814785","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Conference on Computer and Communications Security : proceedings of the ... conference on computer and communications security. ACM Conference on Computer and Communications Security
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