Mobile devices are prevalently used for processing personal private data and sometimes collecting evidence of social injustice or political oppression. The device owners may always feel reluctant to expose this type of data to undesired observers or inspectors. This usually can be achieved by encryption. However, the traditional encryption may not work when an adversary is able to coerce device owners into revealing their encrypted content. Plausibly Deniable Encryption (PDE) is thus designed to protect sensitive data against this type of powerful adversaries. In this paper, we present MobiPluto, a file system friendly PDE scheme for denying the existence of sensitive data stored on mobile devices. MobiPluto achieves deniability feature as nothing but a "side-effect" of combining thin provisioning, a well-established tool in Linux kernel, with encryption. This feature makes MobiPluto more plausible for users to have such software on their mobile devices. A salient difference between MobiPluto and the existing PDE schemes is that MobiPluto is "file system friendly", i.e., any block-based file systems can be deployed on top of it. Thus, it is possible to deploy MobiPluto on most mobile devices. We provide a proof-of-concept implementation for MobiPluto in an Android phone to assess its feasibility and performance.
{"title":"MobiPluto: File System Friendly Deniable Storage for Mobile Devices","authors":"Bing Chang, Zhan Wang, Bo Chen, Fengwei Zhang","doi":"10.1145/2818000.2818046","DOIUrl":"https://doi.org/10.1145/2818000.2818046","url":null,"abstract":"Mobile devices are prevalently used for processing personal private data and sometimes collecting evidence of social injustice or political oppression. The device owners may always feel reluctant to expose this type of data to undesired observers or inspectors. This usually can be achieved by encryption. However, the traditional encryption may not work when an adversary is able to coerce device owners into revealing their encrypted content. Plausibly Deniable Encryption (PDE) is thus designed to protect sensitive data against this type of powerful adversaries. In this paper, we present MobiPluto, a file system friendly PDE scheme for denying the existence of sensitive data stored on mobile devices. MobiPluto achieves deniability feature as nothing but a \"side-effect\" of combining thin provisioning, a well-established tool in Linux kernel, with encryption. This feature makes MobiPluto more plausible for users to have such software on their mobile devices. A salient difference between MobiPluto and the existing PDE schemes is that MobiPluto is \"file system friendly\", i.e., any block-based file systems can be deployed on top of it. Thus, it is possible to deploy MobiPluto on most mobile devices. We provide a proof-of-concept implementation for MobiPluto in an Android phone to assess its feasibility and performance.","PeriodicalId":338725,"journal":{"name":"Proceedings of the 31st Annual Computer Security Applications Conference","volume":"1 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2015-12-07","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"129303318","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}
Giuseppe Petracca, Yuqiong Sun, T. Jaeger, Ahmad Atamli-Reineh
Voice control is a popular way to operate mobile devices, enabling users to communicate requests to their devices. However, adversaries can leverage voice control to trick mobile devices into executing commands to leak secrets or to modify critical information. Contemporary mobile operating systems fail to prevent such attacks because they do not control access to the speaker at all and fail to control when untrusted apps may use the microphone, enabling authorized apps to create exploitable communication channels. In this paper, we propose a security mechanism that tracks the creation of audio communication channels explicitly and controls the information flows over these channels to prevent several types of attacks. We design and implement AuDroid, an extension to the SE Linux reference monitor integrated into the Android operating system for enforcing lattice security policies over the dynamically changing use of system audio resources. To enhance flexibility, when information flow errors are detected, the device owner, system apps and services are given the opportunity to resolve information flow errors using known methods, enabling AuDroid to run many configurations safely. We evaluate our approach on 17 widely-used apps that make extensive use of the microphone and speaker, finding that AuDroid prevents six types of attack scenarios on audio channels while permitting all 17 apps to run effectively. AuDroid shows that it is possible to prevent attacks using audio channels without compromising functionality or introducing significant performance overhead.
{"title":"AuDroid: Preventing Attacks on Audio Channels in Mobile Devices","authors":"Giuseppe Petracca, Yuqiong Sun, T. Jaeger, Ahmad Atamli-Reineh","doi":"10.1145/2818000.2818005","DOIUrl":"https://doi.org/10.1145/2818000.2818005","url":null,"abstract":"Voice control is a popular way to operate mobile devices, enabling users to communicate requests to their devices. However, adversaries can leverage voice control to trick mobile devices into executing commands to leak secrets or to modify critical information. Contemporary mobile operating systems fail to prevent such attacks because they do not control access to the speaker at all and fail to control when untrusted apps may use the microphone, enabling authorized apps to create exploitable communication channels. In this paper, we propose a security mechanism that tracks the creation of audio communication channels explicitly and controls the information flows over these channels to prevent several types of attacks. We design and implement AuDroid, an extension to the SE Linux reference monitor integrated into the Android operating system for enforcing lattice security policies over the dynamically changing use of system audio resources. To enhance flexibility, when information flow errors are detected, the device owner, system apps and services are given the opportunity to resolve information flow errors using known methods, enabling AuDroid to run many configurations safely. We evaluate our approach on 17 widely-used apps that make extensive use of the microphone and speaker, finding that AuDroid prevents six types of attack scenarios on audio channels while permitting all 17 apps to run effectively. AuDroid shows that it is possible to prevent attacks using audio channels without compromising functionality or introducing significant performance overhead.","PeriodicalId":338725,"journal":{"name":"Proceedings of the 31st Annual Computer Security Applications Conference","volume":"57 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2015-12-07","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"124657090","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 emulation has been proven useful in many scenarios, such as software testing, malware analysis, and intrusion response. However, fine-grained software emulation (e.g., at the instruction level) incurs considerable execution overhead (about 8x performance degradation), which hampers its use in production settings. In this paper, we propose MOSE (Live Migration based On-the-fly Software Emulation) that combines the performance advantages of hardware virtualization and the fine-grained analysis capability (comprehensiveness) of whole-system software emulation. Namely, a system can run as normal on a hardware-virtualized platform at near native speed, but when needed, it can be live-migrated to an emulator, not necessarily running on the same physical system, for in-depth analysis and triage; when the analysis is complete, the virtual machine can be migrated back to benefit from full hardware-virtualization again. In this way, the performance degradation is only experienced during analysis and triage. To demonstrate this new capability, we built a proof of concept on-the-fly software emulation system, based on QEMU/KVM and DECAF, the Dynamic Executable Code Analysis Framework. We also perform three case studies: automated kernel panic triage, live-patching a security vulnerability, and on-demand symbolic execution, to illustrate on-demand instruction level analysis.
{"title":"MOSE: Live Migration Based On-the-Fly Software Emulation","authors":"Jinpeng Wei, Lok K. Yan, M. A. Hakim","doi":"10.1145/2818000.2818022","DOIUrl":"https://doi.org/10.1145/2818000.2818022","url":null,"abstract":"Software emulation has been proven useful in many scenarios, such as software testing, malware analysis, and intrusion response. However, fine-grained software emulation (e.g., at the instruction level) incurs considerable execution overhead (about 8x performance degradation), which hampers its use in production settings. In this paper, we propose MOSE (Live Migration based On-the-fly Software Emulation) that combines the performance advantages of hardware virtualization and the fine-grained analysis capability (comprehensiveness) of whole-system software emulation. Namely, a system can run as normal on a hardware-virtualized platform at near native speed, but when needed, it can be live-migrated to an emulator, not necessarily running on the same physical system, for in-depth analysis and triage; when the analysis is complete, the virtual machine can be migrated back to benefit from full hardware-virtualization again. In this way, the performance degradation is only experienced during analysis and triage. To demonstrate this new capability, we built a proof of concept on-the-fly software emulation system, based on QEMU/KVM and DECAF, the Dynamic Executable Code Analysis Framework. We also perform three case studies: automated kernel panic triage, live-patching a security vulnerability, and on-demand symbolic execution, to illustrate on-demand instruction level analysis.","PeriodicalId":338725,"journal":{"name":"Proceedings of the 31st Annual Computer Security Applications Conference","volume":"19 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2015-12-07","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"133228147","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}
Mohammed H. Almeshekah, Christopher N. Gutierrez, M. Atallah, E. Spafford
In this work we present a simple, yet effective and practical, scheme to improve the security of stored password hashes, rendering their cracking detectable and insuperable at the same time. We utilize a machine-dependent function, such as a physically unclonable function (PUF) or a hardware security module (HSM) at the authentication server to prevent off-site password discovery, and a deception mechanism to alert us if such an action is attempted. Our scheme can be easily integrated with legacy systems without the need of any additional servers, changing the structure of the hashed password file or any client modifications. When using the scheme the structure of the hashed passwords file, etc/shadow or etc/master.passwd, will appear no different than in the traditional scheme.1 However, when an attacker exfiltrates the hashed passwords file and tries to crack it, the only passwords he will get are the ersatzpasswords --- the "fake passwords". When an attempt to login using these ersatzpasswords is detected an alarm will be triggered in the system. Even with an adversary who knows about the scheme, cracking cannot be launched without physical access to the authentication server. The scheme also includes a secure backup mechanism in the event of a failure of the hardware dependent function. We discuss our implementation and provide some discussion in comparison to the traditional authentication scheme.
{"title":"ErsatzPasswords: Ending Password Cracking and Detecting Password Leakage","authors":"Mohammed H. Almeshekah, Christopher N. Gutierrez, M. Atallah, E. Spafford","doi":"10.1145/2818000.2818015","DOIUrl":"https://doi.org/10.1145/2818000.2818015","url":null,"abstract":"In this work we present a simple, yet effective and practical, scheme to improve the security of stored password hashes, rendering their cracking detectable and insuperable at the same time. We utilize a machine-dependent function, such as a physically unclonable function (PUF) or a hardware security module (HSM) at the authentication server to prevent off-site password discovery, and a deception mechanism to alert us if such an action is attempted. Our scheme can be easily integrated with legacy systems without the need of any additional servers, changing the structure of the hashed password file or any client modifications. When using the scheme the structure of the hashed passwords file, etc/shadow or etc/master.passwd, will appear no different than in the traditional scheme.1 However, when an attacker exfiltrates the hashed passwords file and tries to crack it, the only passwords he will get are the ersatzpasswords --- the \"fake passwords\". When an attempt to login using these ersatzpasswords is detected an alarm will be triggered in the system. Even with an adversary who knows about the scheme, cracking cannot be launched without physical access to the authentication server. The scheme also includes a secure backup mechanism in the event of a failure of the hardware dependent function. We discuss our implementation and provide some discussion in comparison to the traditional authentication scheme.","PeriodicalId":338725,"journal":{"name":"Proceedings of the 31st Annual Computer Security Applications Conference","volume":"27 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2015-12-07","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"127860242","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}
J. Götzfried, Tilo Müller, Ruan de Clercq, Pieter Maene, F. Freiling, I. Verbauwhede
Protecting the intellectual property of software that is distributed to third-party devices which are not under full control of the software author is difficult to achieve on commodity hardware today. Modern techniques of reverse engineering such as static and dynamic program analysis with system privileges are increasingly powerful, and despite possibilities of encryption, software eventually needs to be processed in clear by the CPU. To anyhow be able to protect software on these devices, a small part of the hardware must be considered trusted. In the past, general purpose trusted computing bases added to desktop computers resulted in costly and rather heavyweight solutions. In contrast, we present Soteria, a lightweight solution for low-cost embedded systems. At its heart, Soteria is a program-counter based memory access control extension for the TI MSP430 microprocessor. Based on our open implementation of Soteria as an openMSP430 extension, and our FPGA-based evaluation, we show that the proposed solution has a minimal performance, size and cost overhead while effectively protecting the confidentiality and integrity of an application's code against all kinds of software attacks including attacks from the system level.
{"title":"Soteria: Offline Software Protection within Low-cost Embedded Devices","authors":"J. Götzfried, Tilo Müller, Ruan de Clercq, Pieter Maene, F. Freiling, I. Verbauwhede","doi":"10.1145/2818000.2856129","DOIUrl":"https://doi.org/10.1145/2818000.2856129","url":null,"abstract":"Protecting the intellectual property of software that is distributed to third-party devices which are not under full control of the software author is difficult to achieve on commodity hardware today. Modern techniques of reverse engineering such as static and dynamic program analysis with system privileges are increasingly powerful, and despite possibilities of encryption, software eventually needs to be processed in clear by the CPU. To anyhow be able to protect software on these devices, a small part of the hardware must be considered trusted. In the past, general purpose trusted computing bases added to desktop computers resulted in costly and rather heavyweight solutions. In contrast, we present Soteria, a lightweight solution for low-cost embedded systems. At its heart, Soteria is a program-counter based memory access control extension for the TI MSP430 microprocessor. Based on our open implementation of Soteria as an openMSP430 extension, and our FPGA-based evaluation, we show that the proposed solution has a minimal performance, size and cost overhead while effectively protecting the confidentiality and integrity of an application's code against all kinds of software attacks including attacks from the system level.","PeriodicalId":338725,"journal":{"name":"Proceedings of the 31st Annual Computer Security Applications Conference","volume":"219 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2015-12-07","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"122840634","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}
Theofilos Petsios, V. Kemerlis, M. Polychronakis, A. Keromytis
Over the past decade many exploit mitigation techniques have been introduced to defend against memory corruption attacks. W^X, ASLR, and canary-based protections are nowadays widely deployed and considered standard practice. However, despite the fact that these techniques have evolved over time, they still suffer from limitations that enable skilled adversaries to bypass them. In this work, we focus on countermeasures against the byte-by-byte discovery of stack canaries in forking programs. This limitation, although known for years, has yet to be addressed effectively, and was recently abused by a series of exploits that allowed for the remote compromise of the popular Nginx web server and a full ASLR bypass in x86-64 Linux. We present DynaGuard, an extension to canary-based protections that further armors hardened applications against brute-force canary attacks. We have implemented DynaGuard in two flavors: a compiler-based version, which incurs an average runtime overhead of 1.2%, and a version based on dynamic binary instrumentation, which can protect binary-only applications without requiring access to source code. We have evaluated both implementations using a set of popular server applications and benchmark suites, and examined how the proposed design overcomes the limitations of previous proposals, ensuring application correctness and seamless integration with third-party software.
{"title":"DynaGuard: Armoring Canary-based Protections against Brute-force Attacks","authors":"Theofilos Petsios, V. Kemerlis, M. Polychronakis, A. Keromytis","doi":"10.1145/2818000.2818031","DOIUrl":"https://doi.org/10.1145/2818000.2818031","url":null,"abstract":"Over the past decade many exploit mitigation techniques have been introduced to defend against memory corruption attacks. W^X, ASLR, and canary-based protections are nowadays widely deployed and considered standard practice. However, despite the fact that these techniques have evolved over time, they still suffer from limitations that enable skilled adversaries to bypass them. In this work, we focus on countermeasures against the byte-by-byte discovery of stack canaries in forking programs. This limitation, although known for years, has yet to be addressed effectively, and was recently abused by a series of exploits that allowed for the remote compromise of the popular Nginx web server and a full ASLR bypass in x86-64 Linux. We present DynaGuard, an extension to canary-based protections that further armors hardened applications against brute-force canary attacks. We have implemented DynaGuard in two flavors: a compiler-based version, which incurs an average runtime overhead of 1.2%, and a version based on dynamic binary instrumentation, which can protect binary-only applications without requiring access to source code. We have evaluated both implementations using a set of popular server applications and benchmark suites, and examined how the proposed design overcomes the limitations of previous proposals, ensuring application correctness and seamless integration with third-party software.","PeriodicalId":338725,"journal":{"name":"Proceedings of the 31st Annual Computer Security Applications Conference","volume":"11 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2015-12-07","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"128059143","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 platforms that use logical partitions to allocate dedicated resources to VMs can benefit from small and therefore secure hypervisors. Many-core platforms, with their abundant resources, are an attractive basis to create and deploy logical partitions on a large scale. However, many-core platforms are designed for efficient cross-core data sharing rather than isolation, which is a key requirement for logical partitions. Typically, logical partitions leverage hardware virtualization extensions that require complex CPU core enhancements. These extensions are not optimal for many-core platforms, where it is preferable to keep the cores as simple as possible. In this paper, we show that a simple address-space isolation mechanism, that can be implemented in the Network-on-Chip of the many-core processor, is sufficient to enable logical partitions. We implement the proposed change for the Intel Single-Chip Cloud Computer (SCC). We also design a cloud architecture that relies on a small and disengaged hypervisor for the security-enhanced Intel SCC. Our prototype hypervisor is 3.4K LOC which is comparable to the smallest hypervisors available today. Furthermore, virtual machines execute bare-metal avoiding runtime interaction with the hypervisor and virtualization overhead.
{"title":"Logical Partitions on Many-Core Platforms","authors":"Ramya Jayaram Masti, Claudio Marforio, Kari Kostiainen, Claudio Soriente, Srdjan Capkun","doi":"10.1145/2818000.2818026","DOIUrl":"https://doi.org/10.1145/2818000.2818026","url":null,"abstract":"Cloud platforms that use logical partitions to allocate dedicated resources to VMs can benefit from small and therefore secure hypervisors. Many-core platforms, with their abundant resources, are an attractive basis to create and deploy logical partitions on a large scale. However, many-core platforms are designed for efficient cross-core data sharing rather than isolation, which is a key requirement for logical partitions. Typically, logical partitions leverage hardware virtualization extensions that require complex CPU core enhancements. These extensions are not optimal for many-core platforms, where it is preferable to keep the cores as simple as possible. In this paper, we show that a simple address-space isolation mechanism, that can be implemented in the Network-on-Chip of the many-core processor, is sufficient to enable logical partitions. We implement the proposed change for the Intel Single-Chip Cloud Computer (SCC). We also design a cloud architecture that relies on a small and disengaged hypervisor for the security-enhanced Intel SCC. Our prototype hypervisor is 3.4K LOC which is comparable to the smallest hypervisors available today. Furthermore, virtual machines execute bare-metal avoiding runtime interaction with the hypervisor and virtualization overhead.","PeriodicalId":338725,"journal":{"name":"Proceedings of the 31st Annual Computer Security Applications Conference","volume":"33 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2015-12-07","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"131891007","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}
S. Ji, Shukun Yang, Ting Wang, Changchang Liu, Wei-Han Lee, R. Beyah
In this paper, we introduce an open-source and modular password analysis and research system, PARS, which provides a uniform, comprehensive and scalable research platform for password security. To the best of our knowledge, PARS is the first such system that enables researchers to conduct fair and comparable password security research. PARS contains 12 state-of-the-art cracking algorithms, 15 intra-site and cross-site password strength metrics, 8 academic password meters, and 15 of the 24 commercial password meters from the top-150 websites ranked by Alexa. Also, detailed taxonomies and large-scale evaluations of the PARS modules are presented in the paper.
{"title":"PARS: A Uniform and Open-source Password Analysis and Research System","authors":"S. Ji, Shukun Yang, Ting Wang, Changchang Liu, Wei-Han Lee, R. Beyah","doi":"10.1145/2818000.2818018","DOIUrl":"https://doi.org/10.1145/2818000.2818018","url":null,"abstract":"In this paper, we introduce an open-source and modular password analysis and research system, PARS, which provides a uniform, comprehensive and scalable research platform for password security. To the best of our knowledge, PARS is the first such system that enables researchers to conduct fair and comparable password security research. PARS contains 12 state-of-the-art cracking algorithms, 15 intra-site and cross-site password strength metrics, 8 academic password meters, and 15 of the 24 commercial password meters from the top-150 websites ranked by Alexa. Also, detailed taxonomies and large-scale evaluations of the PARS modules are presented in the paper.","PeriodicalId":338725,"journal":{"name":"Proceedings of the 31st Annual Computer Security Applications Conference","volume":"1 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2015-12-07","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"116041977","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}
SQLite is the most widely deployed in-process library that implements a SQL database engine. It offers high storage efficiency, fast query operation and small memory needs. Due to the fact that a complete SQLite database is stored in a single cross-platform disk file and SQLite does not support multiple users, anyone who has direct access to the file can read the whole database content. SELinux was originally developed as a Mandatory Access Control (MAC) mechanism for Linux to demonstrate how to overcome DAC limitations. However, SELinux provides per-file protection, thus the database file is treated as an atomic unit, impeding the definition of a fine-grained mandatory access control (MAC) policy for database objects. We introduce SeSQLite, an SQLite extension that integrates SELinux access controls into SQLite with minimal performance and storage overhead. SeSQLite implements labeling and access control at both schema level (for tables and columns) and row level. This permits the management of a fine-grained access policy for database objects. A prototype has been implemented and it has been used to improve the security of Android Content Providers.
{"title":"SeSQLite: Security Enhanced SQLite: Mandatory Access Control for Android databases","authors":"S. Mutti, Enrico Bacis, S. Paraboschi","doi":"10.1145/2818000.2818041","DOIUrl":"https://doi.org/10.1145/2818000.2818041","url":null,"abstract":"SQLite is the most widely deployed in-process library that implements a SQL database engine. It offers high storage efficiency, fast query operation and small memory needs. Due to the fact that a complete SQLite database is stored in a single cross-platform disk file and SQLite does not support multiple users, anyone who has direct access to the file can read the whole database content. SELinux was originally developed as a Mandatory Access Control (MAC) mechanism for Linux to demonstrate how to overcome DAC limitations. However, SELinux provides per-file protection, thus the database file is treated as an atomic unit, impeding the definition of a fine-grained mandatory access control (MAC) policy for database objects. We introduce SeSQLite, an SQLite extension that integrates SELinux access controls into SQLite with minimal performance and storage overhead. SeSQLite implements labeling and access control at both schema level (for tables and columns) and row level. This permits the management of a fine-grained access policy for database objects. A prototype has been implemented and it has been used to improve the security of Android Content Providers.","PeriodicalId":338725,"journal":{"name":"Proceedings of the 31st Annual Computer Security Applications Conference","volume":"82 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2015-12-07","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"121207243","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}
Song Gao, Manar Mohamed, Nitesh Saxena, Chengcui Zhang
CAPTCHAs represent an important pillar in the web security domain. Yet, current CAPTCHAs do not fully meet the web security requirements. Many existing CAPTCHAs can be broken using automated attacks based on image processing and machine learning techniques. Moreover, most existing CAPTCHAs are completely vulnerable to human-solver relay attacks, whereby CAPTCHA challenges are simply outsourced to a remote human solver. In this paper, we introduce a new class of CAPTCHAs that can not only resist automated attacks but can also make relay attacks hard and detectable. These CAPTCHAs are carefully built on the notions of dynamic cognitive games (DCG) and emerging images (EI), present in the literature. While existing CAPTCHAs based on the DCG notion alone (e.g., an object matching game embedded in a clear background) are prone to automated attacks and those based on the EI notion alone (e.g., moving text embedded in emerging images) are prone to relay attacks, we show that a careful amalgamation of the two notions can resist both forms of attacks. Specifically, we formalize, design and implement a concrete instantiation of EI-DCG CAPTCHAs, and demonstrate its security with respect to image processing and object tracking techniques as well as their resistance to and detectability of relay attacks.
{"title":"Emerging Image Game CAPTCHAs for Resisting Automated and Human-Solver Relay Attacks","authors":"Song Gao, Manar Mohamed, Nitesh Saxena, Chengcui Zhang","doi":"10.1145/2818000.2818006","DOIUrl":"https://doi.org/10.1145/2818000.2818006","url":null,"abstract":"CAPTCHAs represent an important pillar in the web security domain. Yet, current CAPTCHAs do not fully meet the web security requirements. Many existing CAPTCHAs can be broken using automated attacks based on image processing and machine learning techniques. Moreover, most existing CAPTCHAs are completely vulnerable to human-solver relay attacks, whereby CAPTCHA challenges are simply outsourced to a remote human solver. In this paper, we introduce a new class of CAPTCHAs that can not only resist automated attacks but can also make relay attacks hard and detectable. These CAPTCHAs are carefully built on the notions of dynamic cognitive games (DCG) and emerging images (EI), present in the literature. While existing CAPTCHAs based on the DCG notion alone (e.g., an object matching game embedded in a clear background) are prone to automated attacks and those based on the EI notion alone (e.g., moving text embedded in emerging images) are prone to relay attacks, we show that a careful amalgamation of the two notions can resist both forms of attacks. Specifically, we formalize, design and implement a concrete instantiation of EI-DCG CAPTCHAs, and demonstrate its security with respect to image processing and object tracking techniques as well as their resistance to and detectability of relay attacks.","PeriodicalId":338725,"journal":{"name":"Proceedings of the 31st Annual Computer Security Applications Conference","volume":"23 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2015-12-07","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"126596075","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}
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