Website fingerprinting enables an eavesdropper to determine which websites a user is visiting over an encrypted connection. State-of-the-art website fingerprinting (WF) attacks have demonstrated effectiveness even against Tor-protected network traffic. However, existing WF attacks have critical limitations on accurately identifying websites in multi-tab browsing sessions, where the holistic pattern of individual websites is no longer preserved, and the number of tabs opened by a client is unknown a priori. In this paper, we propose ARES, a novel WF framework natively designed for multi-tab WF attacks. ARES formulates the multi-tab attack as a multi-label classification problem and solves it using a multi-classifier framework. Each classifier, designed based on a novel transformer model, identifies a specific website using its local patterns extracted from multiple traffic segments. We implement a prototype of ARES and extensively evaluate its effectiveness using our large-scale dataset collected over multiple months (by far the largest multi-tab WF dataset studied in academic papers.) The experimental results illustrate that ARES effectively achieves the multi-tab WF attack with the best F1-score of 0.907. Further, ARES remains robust even against various WF defenses.
{"title":"Robust Multi-tab Website Fingerprinting Attacks in the Wild","authors":"Xinhao Deng, Qilei Yin, Zhuotao Liu, Xiyuan Zhao, Qi Li, Mingwei Xu, Ke Xu, Jianping Wu","doi":"10.1109/SP46215.2023.10179464","DOIUrl":"https://doi.org/10.1109/SP46215.2023.10179464","url":null,"abstract":"Website fingerprinting enables an eavesdropper to determine which websites a user is visiting over an encrypted connection. State-of-the-art website fingerprinting (WF) attacks have demonstrated effectiveness even against Tor-protected network traffic. However, existing WF attacks have critical limitations on accurately identifying websites in multi-tab browsing sessions, where the holistic pattern of individual websites is no longer preserved, and the number of tabs opened by a client is unknown a priori. In this paper, we propose ARES, a novel WF framework natively designed for multi-tab WF attacks. ARES formulates the multi-tab attack as a multi-label classification problem and solves it using a multi-classifier framework. Each classifier, designed based on a novel transformer model, identifies a specific website using its local patterns extracted from multiple traffic segments. We implement a prototype of ARES and extensively evaluate its effectiveness using our large-scale dataset collected over multiple months (by far the largest multi-tab WF dataset studied in academic papers.) The experimental results illustrate that ARES effectively achieves the multi-tab WF attack with the best F1-score of 0.907. Further, ARES remains robust even against various WF defenses.","PeriodicalId":439989,"journal":{"name":"2023 IEEE Symposium on Security and Privacy (SP)","volume":"198199 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2023-05-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"115575625","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}
Blockchain is a decentralized distributed system on which a large number of financial applications have been deployed. The consensus process in it plays an important role, which guarantees that legal transactions on the chain can be executed and recorded fairly and consistently. However, because of Consensus Failure Bugs (CFBs), many blockchain systems do not provide even this basic guarantee. The validity and consistency of blockchain systems rely on the soundness of complex consensus logic implementation. Any bugs which cause the blockchain consensus failure can be crucial.In this work, we introduce Tyr, an open-source tool for detecting CFBs in blockchain systems with a large number of abnormal divergent consensus behaviors. First, we design four oracle detectors to monitor the behaviors of nodes and analyze the violation of consensus properties. To trigger these oracles effectively, Tyr harnesses a behavior divergent model to constantly generate consensus messages and make nodes behave as differently as possible. We implemented and evaluated Tyr on six widely used commercial blockchain consensus systems, including IBM Fabric, WeBank FISCO-BCOS, ConsenSys Quorum, Facebook Diem, Go-Ethereum, and EOS. Compared with the state-of-the-art tools Peach, Fluffy, and Twins, Tyr covers 27.3%, 228.2%, and 297.1% more branches, respectively. Furthermore, Tyr has detected 20 serious previously unknown vulnerabilities, all of which have been repaired by the corresponding maintainers.
{"title":"Tyr: Finding Consensus Failure Bugs in Blockchain System with Behaviour Divergent Model","authors":"Yuanliang Chen, Fuchen Ma, Yuanhang Zhou, Yu Jiang, Ting Chen, Jiaguang Sun","doi":"10.1109/SP46215.2023.10179386","DOIUrl":"https://doi.org/10.1109/SP46215.2023.10179386","url":null,"abstract":"Blockchain is a decentralized distributed system on which a large number of financial applications have been deployed. The consensus process in it plays an important role, which guarantees that legal transactions on the chain can be executed and recorded fairly and consistently. However, because of Consensus Failure Bugs (CFBs), many blockchain systems do not provide even this basic guarantee. The validity and consistency of blockchain systems rely on the soundness of complex consensus logic implementation. Any bugs which cause the blockchain consensus failure can be crucial.In this work, we introduce Tyr, an open-source tool for detecting CFBs in blockchain systems with a large number of abnormal divergent consensus behaviors. First, we design four oracle detectors to monitor the behaviors of nodes and analyze the violation of consensus properties. To trigger these oracles effectively, Tyr harnesses a behavior divergent model to constantly generate consensus messages and make nodes behave as differently as possible. We implemented and evaluated Tyr on six widely used commercial blockchain consensus systems, including IBM Fabric, WeBank FISCO-BCOS, ConsenSys Quorum, Facebook Diem, Go-Ethereum, and EOS. Compared with the state-of-the-art tools Peach, Fluffy, and Twins, Tyr covers 27.3%, 228.2%, and 297.1% more branches, respectively. Furthermore, Tyr has detected 20 serious previously unknown vulnerabilities, all of which have been repaired by the corresponding maintainers.","PeriodicalId":439989,"journal":{"name":"2023 IEEE Symposium on Security and Privacy (SP)","volume":"15 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2023-05-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"115645164","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}
Pub Date : 2023-05-01DOI: 10.1109/SP46215.2023.10179285
Arslan Khan, Dongyan Xu, D. Tian
Embedded systems comprise of low-power microcontrollers and constitute computing systems from IoT nodes to supercomputers. Unfortunately, due to the low power constraint, the security of these systems is often overlooked, leaving a huge attack surface. For instance, an attacker compromising a user task can access any kernel data structure. Existing work has applied compartmentalization to reduce the attack surface, but these systems either incur a high runtime overhead or require major modifications to existing firmware. In this paper, we present Embedded Compartmentalizer (EC), a comprehensive and automatic compartmentalization toolchain for Real-Time Operating Systems (RTOSs) and baremetal firmware. EC provides the Embedded Compartmentalizer Compiler (ECC) to automatically partition firmware into different compartments and enforces memory protection among them using the Embedded Compartmentalizer Kernel (ECK), a formally verified microkernel implementing a novel architecture for compartmentalizing firmware using intra-kernel isolation. Our evaluation shows that EC is 1.2x faster than state-of-the-art systems and can achieve up to 96.2% ROP gadget reduction in firmwares. EC provides a low-cost, practical, and effective compartmentalization solution for embedded systems with memory protection and debug hardware extension.
{"title":"EC: Embedded Systems Compartmentalization via Intra-Kernel Isolation","authors":"Arslan Khan, Dongyan Xu, D. Tian","doi":"10.1109/SP46215.2023.10179285","DOIUrl":"https://doi.org/10.1109/SP46215.2023.10179285","url":null,"abstract":"Embedded systems comprise of low-power microcontrollers and constitute computing systems from IoT nodes to supercomputers. Unfortunately, due to the low power constraint, the security of these systems is often overlooked, leaving a huge attack surface. For instance, an attacker compromising a user task can access any kernel data structure. Existing work has applied compartmentalization to reduce the attack surface, but these systems either incur a high runtime overhead or require major modifications to existing firmware. In this paper, we present Embedded Compartmentalizer (EC), a comprehensive and automatic compartmentalization toolchain for Real-Time Operating Systems (RTOSs) and baremetal firmware. EC provides the Embedded Compartmentalizer Compiler (ECC) to automatically partition firmware into different compartments and enforces memory protection among them using the Embedded Compartmentalizer Kernel (ECK), a formally verified microkernel implementing a novel architecture for compartmentalizing firmware using intra-kernel isolation. Our evaluation shows that EC is 1.2x faster than state-of-the-art systems and can achieve up to 96.2% ROP gadget reduction in firmwares. EC provides a low-cost, practical, and effective compartmentalization solution for embedded systems with memory protection and debug hardware extension.","PeriodicalId":439989,"journal":{"name":"2023 IEEE Symposium on Security and Privacy (SP)","volume":"4 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2023-05-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"123010220","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}
Pub Date : 2023-05-01DOI: 10.1109/SP46215.2023.10179318
A. Loveless, L. T. Phan, R. Dreslinski, Baris Kasikci
Designers are increasingly using mixed-criticality networks in embedded systems to reduce size, weight, power, and cost. Perhaps the most successful of these technologies is Time-Triggered Ethernet (TTE), which lets critical time-triggered (TT) traffic and non-critical best-effort (BE) traffic share the same switches and cabling. A key aspect of TTE is that the TT part of the system is isolated from the BE part, and thus BE devices have no way to disrupt the operation of the TTE devices. This isolation allows designers to: (1) use untrusted, but low cost, BE hardware, (2) lower BE security requirements, and (3) ignore BE devices during safety reviews and certification procedures.We present PCSPOOF, the first attack to break TTE’s isolation guarantees. PCSPOOF is based on two key observations. First, it is possible for a BE device to infer private information about the TT part of the network that can be used to craft malicious synchronization messages. Second, by injecting electrical noise into a TTE switch over an Ethernet cable, a BE device can trick the switch into sending these malicious synchronization messages to other TTE devices. Our evaluation shows that successful attacks are possible in seconds, and that each successful attack can cause TTE devices to lose synchronization for up to a second and drop tens of TT messages — both of which can result in the failure of critical systems like aircraft or automobiles. We also show that, in a simulated spaceflight mission, PCSPOOF causes uncontrolled maneuvers that threaten safety and mission success. We disclosed PCSPOOF to aerospace companies using TTE, and several are implementing mitigations from this paper.
{"title":"PCSPOOF: Compromising the Safety of Time-Triggered Ethernet","authors":"A. Loveless, L. T. Phan, R. Dreslinski, Baris Kasikci","doi":"10.1109/SP46215.2023.10179318","DOIUrl":"https://doi.org/10.1109/SP46215.2023.10179318","url":null,"abstract":"Designers are increasingly using mixed-criticality networks in embedded systems to reduce size, weight, power, and cost. Perhaps the most successful of these technologies is Time-Triggered Ethernet (TTE), which lets critical time-triggered (TT) traffic and non-critical best-effort (BE) traffic share the same switches and cabling. A key aspect of TTE is that the TT part of the system is isolated from the BE part, and thus BE devices have no way to disrupt the operation of the TTE devices. This isolation allows designers to: (1) use untrusted, but low cost, BE hardware, (2) lower BE security requirements, and (3) ignore BE devices during safety reviews and certification procedures.We present PCSPOOF, the first attack to break TTE’s isolation guarantees. PCSPOOF is based on two key observations. First, it is possible for a BE device to infer private information about the TT part of the network that can be used to craft malicious synchronization messages. Second, by injecting electrical noise into a TTE switch over an Ethernet cable, a BE device can trick the switch into sending these malicious synchronization messages to other TTE devices. Our evaluation shows that successful attacks are possible in seconds, and that each successful attack can cause TTE devices to lose synchronization for up to a second and drop tens of TT messages — both of which can result in the failure of critical systems like aircraft or automobiles. We also show that, in a simulated spaceflight mission, PCSPOOF causes uncontrolled maneuvers that threaten safety and mission success. We disclosed PCSPOOF to aerospace companies using TTE, and several are implementing mitigations from this paper.","PeriodicalId":439989,"journal":{"name":"2023 IEEE Symposium on Security and Privacy (SP)","volume":"585 1 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2023-05-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"122722964","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}
Pub Date : 2023-05-01DOI: 10.1109/SP46215.2023.10179355
B. Shivakumar, J. Barnes, G. Barthe, S. Cauligi, C. Chuengsatiansup, Daniel Genkin, Sioli O'Connell, P. Schwabe, Rui Qi Sim, Y. Yarom
Practical information-flow programming languages commonly allow controlled leakage via a declassify construct—programmers can use this construct to declare intentional leakage. For instance, cryptographic signatures and ciphertexts, which are computed from private keys, are viewed as secret by information-flow analyses. Cryptographic libraries can use declassify to make this data public, as it is no longer sensitive.In this paper, we study the interaction between speculative execution and declassification. We show that speculative execution leads to unintended leakage from declassification sites. Concretely, we present a PoC that recovers keys from AES implementations. Our PoC is an instance of a Spectre attack, and remains effective even when programs are compiled with speculative load hardening (SLH), a widespread compiler-based countermeasure against Spectre. We develop formal countermeasures against these attacks, including a significant improvement to SLH we term selective speculative load hardening (selSLH). These countermeasures soundly enforce relative non-interference (RNI): Informally, the speculative leakage of a protected program is limited to the existing sequential leakage of the original program. We implement our simplest countermeasure in the FaCT language and compiler—which is designed specifically for high-assurance cryptography—and we see performance overheads of at most 10%. Finally, although we do not directly implement selSLH, our preliminary evaluation suggests a significant reduction in performance cost for cryptographic functions as compared to traditional SLH.
{"title":"Spectre Declassified: Reading from the Right Place at the Wrong Time","authors":"B. Shivakumar, J. Barnes, G. Barthe, S. Cauligi, C. Chuengsatiansup, Daniel Genkin, Sioli O'Connell, P. Schwabe, Rui Qi Sim, Y. Yarom","doi":"10.1109/SP46215.2023.10179355","DOIUrl":"https://doi.org/10.1109/SP46215.2023.10179355","url":null,"abstract":"Practical information-flow programming languages commonly allow controlled leakage via a declassify construct—programmers can use this construct to declare intentional leakage. For instance, cryptographic signatures and ciphertexts, which are computed from private keys, are viewed as secret by information-flow analyses. Cryptographic libraries can use declassify to make this data public, as it is no longer sensitive.In this paper, we study the interaction between speculative execution and declassification. We show that speculative execution leads to unintended leakage from declassification sites. Concretely, we present a PoC that recovers keys from AES implementations. Our PoC is an instance of a Spectre attack, and remains effective even when programs are compiled with speculative load hardening (SLH), a widespread compiler-based countermeasure against Spectre. We develop formal countermeasures against these attacks, including a significant improvement to SLH we term selective speculative load hardening (selSLH). These countermeasures soundly enforce relative non-interference (RNI): Informally, the speculative leakage of a protected program is limited to the existing sequential leakage of the original program. We implement our simplest countermeasure in the FaCT language and compiler—which is designed specifically for high-assurance cryptography—and we see performance overheads of at most 10%. Finally, although we do not directly implement selSLH, our preliminary evaluation suggests a significant reduction in performance cost for cryptographic functions as compared to traditional SLH.","PeriodicalId":439989,"journal":{"name":"2023 IEEE Symposium on Security and Privacy (SP)","volume":"362 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2023-05-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"125652240","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}
Pub Date : 2023-05-01DOI: 10.1109/SP46215.2023.10179458
Zizhi Jin, Xiaoyu Ji, Yushi Cheng, Bo Yang, Chen Yan, Wenyuan Xu
Autonomous vehicles and robots increasingly exploit LiDAR-based 3D object detection systems to detect obstacles in environment. Correct detection and classification are important to ensure safe driving. Though existing work has demonstrated the feasibility of manipulating point clouds to spoof 3D object detectors, most of the attempts are conducted digitally. In this paper, we investigate the possibility of physically fooling LiDAR-based 3D object detection by injecting adversarial point clouds using lasers. First, we develop a laser transceiver that can inject up to 4200 points, which is 20 times more than prior work, and can measure the scanning cycle of victim LiDARs to schedule the spoofing laser signals. By designing a control signal method that converts the coordinates of point clouds to control signals and an adversarial point cloud optimization method with physical constraints of LiDARs and attack capabilities, we manage to inject spoofing point cloud with desired point cloud shapes into the victim LiDAR physically. We can launch four types of attacks, i.e., naive hiding, record-based creating, optimization-based hiding, and optimization-based creating. Extensive experiments demonstrate the effectiveness of our attacks against two commercial LiDAR and three detectors. We also discuss defense strategies at the sensor and AV system levels.
{"title":"PLA-LiDAR: Physical Laser Attacks against LiDAR-based 3D Object Detection in Autonomous Vehicle","authors":"Zizhi Jin, Xiaoyu Ji, Yushi Cheng, Bo Yang, Chen Yan, Wenyuan Xu","doi":"10.1109/SP46215.2023.10179458","DOIUrl":"https://doi.org/10.1109/SP46215.2023.10179458","url":null,"abstract":"Autonomous vehicles and robots increasingly exploit LiDAR-based 3D object detection systems to detect obstacles in environment. Correct detection and classification are important to ensure safe driving. Though existing work has demonstrated the feasibility of manipulating point clouds to spoof 3D object detectors, most of the attempts are conducted digitally. In this paper, we investigate the possibility of physically fooling LiDAR-based 3D object detection by injecting adversarial point clouds using lasers. First, we develop a laser transceiver that can inject up to 4200 points, which is 20 times more than prior work, and can measure the scanning cycle of victim LiDARs to schedule the spoofing laser signals. By designing a control signal method that converts the coordinates of point clouds to control signals and an adversarial point cloud optimization method with physical constraints of LiDARs and attack capabilities, we manage to inject spoofing point cloud with desired point cloud shapes into the victim LiDAR physically. We can launch four types of attacks, i.e., naive hiding, record-based creating, optimization-based hiding, and optimization-based creating. Extensive experiments demonstrate the effectiveness of our attacks against two commercial LiDAR and three detectors. We also discuss defense strategies at the sensor and AV system levels.","PeriodicalId":439989,"journal":{"name":"2023 IEEE Symposium on Security and Privacy (SP)","volume":"11 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2023-05-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"114260758","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 virtual machine interacts with its host environment through virtual devices, driven by virtual device messages, e.g., I/O operations. By issuing crafted messages, an adversary can exploit a vulnerability in a virtual device to escape the virtual machine, gaining host access. Even though hundreds of bugs in virtual devices have been discovered, coverage-based virtual device fuzzers hardly consider intra-message dependencies (a field in a virtual device message may be dependent on another field) and inter-message dependencies (a message may depend on a previously issued message), thus resulting in limited scalability or efficiency.ViDeZZo, our new dependency-aware fuzzing framework for virtual devices, overcomes the limitations of existing virtual device fuzzers by annotating intra-message dependencies with a lightweight grammar, and by self-learning inter-message dependencies with new mutation rules. Specifically, ViDeZZo annotates message dependencies and applies three categories of message mutators. This approach avoids heavy manual effort to analyze specifications and speeds up the slow exploration by satisfying dependencies, resulting in a scalable and efficient fuzzer that boosts bug discovery in virtual devices.In our evaluation, ViDeZZo covers two hypervisors, four architectures, five device categories, and 28 virtual devices, and reaches competitive coverage faster. Moreover, ViDeZZo successfully finds 24 existing and 28 new bugs across diverse bug types. We are actively engaging with the community with 7 of our submitted patches already accepted.
{"title":"ViDeZZo: Dependency-aware Virtual Device Fuzzing","authors":"Qiang Liu, Flavio Toffalini, Yajin Zhou, Mathias Payer","doi":"10.1109/SP46215.2023.10179354","DOIUrl":"https://doi.org/10.1109/SP46215.2023.10179354","url":null,"abstract":"A virtual machine interacts with its host environment through virtual devices, driven by virtual device messages, e.g., I/O operations. By issuing crafted messages, an adversary can exploit a vulnerability in a virtual device to escape the virtual machine, gaining host access. Even though hundreds of bugs in virtual devices have been discovered, coverage-based virtual device fuzzers hardly consider intra-message dependencies (a field in a virtual device message may be dependent on another field) and inter-message dependencies (a message may depend on a previously issued message), thus resulting in limited scalability or efficiency.ViDeZZo, our new dependency-aware fuzzing framework for virtual devices, overcomes the limitations of existing virtual device fuzzers by annotating intra-message dependencies with a lightweight grammar, and by self-learning inter-message dependencies with new mutation rules. Specifically, ViDeZZo annotates message dependencies and applies three categories of message mutators. This approach avoids heavy manual effort to analyze specifications and speeds up the slow exploration by satisfying dependencies, resulting in a scalable and efficient fuzzer that boosts bug discovery in virtual devices.In our evaluation, ViDeZZo covers two hypervisors, four architectures, five device categories, and 28 virtual devices, and reaches competitive coverage faster. Moreover, ViDeZZo successfully finds 24 existing and 28 new bugs across diverse bug types. We are actively engaging with the community with 7 of our submitted patches already accepted.","PeriodicalId":439989,"journal":{"name":"2023 IEEE Symposium on Security and Privacy (SP)","volume":"58 ","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2023-05-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"133945123","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}
Pub Date : 2023-05-01DOI: 10.1109/SP46215.2023.10179418
B. Shivakumar, G. Barthe, B. Grégoire, Vincent Laporte, Tiago Oliveira, Swarn Priya, P. Schwabe, Lucas Tabary-Maujean
The current gold standard of cryptographic software is to write efficient libraries with systematic protections against timing attacks. In order to meet this goal, cryptographic engineers increasingly use high-assurance cryptography tools. These tools guide programmers and provide rigorous guarantees that can be verified independently by library users. However, high-assurance tools reason about overly simple execution models that elide transient execution leakage. Thus, implementations validated by high-assurance cryptography tools remain potentially vulnerable to transient execution attacks such as Spectre or Meltdown. Moreover, proposed countermeasures are not used in practice due to performance overhead.We propose, analyze, implement and evaluate an approach for writing efficient cryptographic implementations that are protected against Spectre v1 attacks. Our approach ensures speculative constant-time, an information flow property which guarantees that programs are protected against Spectre v1. Speculative constant-time is enforced by means of a (value-dependent) information flow type system. The type system tracks security levels depending on whether execution is misspeculating. We implement our approach in the Jasmin framework for high-assurance cryptography, and use it for protecting all implementations of an experimental cryptographic library that includes highly optimized implementations of symmetric primitives, of elliptic-curve cryptography, and of Kyber, a lattice-based KEM recently selected by NIST for standardization. The performance impact of our protections is very low; for example, less than 1% for Kyber and essentially zero for X25519.
{"title":"Typing High-Speed Cryptography against Spectre v1","authors":"B. Shivakumar, G. Barthe, B. Grégoire, Vincent Laporte, Tiago Oliveira, Swarn Priya, P. Schwabe, Lucas Tabary-Maujean","doi":"10.1109/SP46215.2023.10179418","DOIUrl":"https://doi.org/10.1109/SP46215.2023.10179418","url":null,"abstract":"The current gold standard of cryptographic software is to write efficient libraries with systematic protections against timing attacks. In order to meet this goal, cryptographic engineers increasingly use high-assurance cryptography tools. These tools guide programmers and provide rigorous guarantees that can be verified independently by library users. However, high-assurance tools reason about overly simple execution models that elide transient execution leakage. Thus, implementations validated by high-assurance cryptography tools remain potentially vulnerable to transient execution attacks such as Spectre or Meltdown. Moreover, proposed countermeasures are not used in practice due to performance overhead.We propose, analyze, implement and evaluate an approach for writing efficient cryptographic implementations that are protected against Spectre v1 attacks. Our approach ensures speculative constant-time, an information flow property which guarantees that programs are protected against Spectre v1. Speculative constant-time is enforced by means of a (value-dependent) information flow type system. The type system tracks security levels depending on whether execution is misspeculating. We implement our approach in the Jasmin framework for high-assurance cryptography, and use it for protecting all implementations of an experimental cryptographic library that includes highly optimized implementations of symmetric primitives, of elliptic-curve cryptography, and of Kyber, a lattice-based KEM recently selected by NIST for standardization. The performance impact of our protections is very low; for example, less than 1% for Kyber and essentially zero for X25519.","PeriodicalId":439989,"journal":{"name":"2023 IEEE Symposium on Security and Privacy (SP)","volume":"1 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2023-05-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"130446729","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}
Pub Date : 2023-05-01DOI: 10.1109/SP46215.2023.10179349
Sarah Scheffler, Anunay Kulshrestha, Jonathan R. Mayer
End-to-end encryption (E2EE) prevents online services from accessing user content. This important security property is also an obstacle for content moderation methods that involve content analysis. The tension between E2EE and efforts to combat child sexual abuse material (CSAM) has become a global flashpoint in encryption policy, because the predominant method of detecting harmful content—server-side perceptual hash matching on plaintext images—is unavailable.Recent applied cryptography advances enable private hash matching (PHM), where a service can match user content against a set of known CSAM images without revealing the hash set to users or nonmatching content to the service. These designs, especially a 2021 proposal for identifying CSAM in Apple’s iCloud Photos service, have attracted widespread criticism for creating risks to security, privacy, and free expression.In this work, we aim to advance scholarship and dialogue about PHM by contributing new cryptographic methods for system verification by the general public. We begin with motivation, describing the rationale for PHM to detect CSAM and the serious societal and technical issues with its deployment. Verification could partially address shortcomings of PHM, and we systematize critiques into two areas for auditing: trust in the hash set and trust in the implementation. We explain how, while these two issues cannot be fully resolved by technology alone, there are possible cryptographic trust improvements.The central contributions of this paper are novel cryptographic protocols that enable three types of public verification for PHM systems: (1) certification that external groups approve the hash set, (2) proof that particular lawful content is not in the hash set, and (3) eventual notification to users of false positive matches. The protocols that we describe are practical, efficient, and compatible with existing PHM constructions.
{"title":"Public Verification for Private Hash Matching","authors":"Sarah Scheffler, Anunay Kulshrestha, Jonathan R. Mayer","doi":"10.1109/SP46215.2023.10179349","DOIUrl":"https://doi.org/10.1109/SP46215.2023.10179349","url":null,"abstract":"End-to-end encryption (E2EE) prevents online services from accessing user content. This important security property is also an obstacle for content moderation methods that involve content analysis. The tension between E2EE and efforts to combat child sexual abuse material (CSAM) has become a global flashpoint in encryption policy, because the predominant method of detecting harmful content—server-side perceptual hash matching on plaintext images—is unavailable.Recent applied cryptography advances enable private hash matching (PHM), where a service can match user content against a set of known CSAM images without revealing the hash set to users or nonmatching content to the service. These designs, especially a 2021 proposal for identifying CSAM in Apple’s iCloud Photos service, have attracted widespread criticism for creating risks to security, privacy, and free expression.In this work, we aim to advance scholarship and dialogue about PHM by contributing new cryptographic methods for system verification by the general public. We begin with motivation, describing the rationale for PHM to detect CSAM and the serious societal and technical issues with its deployment. Verification could partially address shortcomings of PHM, and we systematize critiques into two areas for auditing: trust in the hash set and trust in the implementation. We explain how, while these two issues cannot be fully resolved by technology alone, there are possible cryptographic trust improvements.The central contributions of this paper are novel cryptographic protocols that enable three types of public verification for PHM systems: (1) certification that external groups approve the hash set, (2) proof that particular lawful content is not in the hash set, and (3) eventual notification to users of false positive matches. The protocols that we describe are practical, efficient, and compatible with existing PHM constructions.","PeriodicalId":439989,"journal":{"name":"2023 IEEE Symposium on Security and Privacy (SP)","volume":"1 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2023-05-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"133565739","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}
Pub Date : 2023-05-01DOI: 10.1109/SP46215.2023.10179335
Zhen Sun, Vitaly Shmatikov
Covert, censorship-resistant communication in the presence of nation-state adversaries requires unobservable channels whose operation is difficult to detect via network-traffic analysis. Traffic substitution, i.e., replacing data transmitted by a "cover" application with covert content, takes advantage of already-existing encrypted channels to produce traffic that is statistically indistinguishable from the traffic of the cover application and thus difficult to censor.Online games are a promising platform for building circumvention channels due to their popularity in many censored regions. We show, however, that previously proposed traffic substitution methods cannot be directly applied to games. Their traces, even if statistically similar to game traces, may violate game-specific invariants and are thus easy to detect because they could not have been generated by an actual gameplay.We explain how to identify non-disruptive content whose substitution does not result in client-server inconsistencies and use these ideas to design and implement Telepath, a covert communication system that uses Minecraft as the platform. Telepath takes advantage of (1) Minecraft’s encrypted client-server channel, (2) decentralized architecture that enables individual users to run their own servers, and (3) popularity of "mods" that add functionality to Minecraft clients and servers. Telepath runs a Minecraft game but substitutes non-disruptive in-game messages with covert content, without changing the game’s interaction with the network manager.We measure performance of Telepath for Web browsing and audio streaming, and show that network traffic generated by Telepath resists statistical traffic analysis that aims to distinguish it from popular Minecraft bots.
{"title":"Telepath: A Minecraft-based Covert Communication System","authors":"Zhen Sun, Vitaly Shmatikov","doi":"10.1109/SP46215.2023.10179335","DOIUrl":"https://doi.org/10.1109/SP46215.2023.10179335","url":null,"abstract":"Covert, censorship-resistant communication in the presence of nation-state adversaries requires unobservable channels whose operation is difficult to detect via network-traffic analysis. Traffic substitution, i.e., replacing data transmitted by a \"cover\" application with covert content, takes advantage of already-existing encrypted channels to produce traffic that is statistically indistinguishable from the traffic of the cover application and thus difficult to censor.Online games are a promising platform for building circumvention channels due to their popularity in many censored regions. We show, however, that previously proposed traffic substitution methods cannot be directly applied to games. Their traces, even if statistically similar to game traces, may violate game-specific invariants and are thus easy to detect because they could not have been generated by an actual gameplay.We explain how to identify non-disruptive content whose substitution does not result in client-server inconsistencies and use these ideas to design and implement Telepath, a covert communication system that uses Minecraft as the platform. Telepath takes advantage of (1) Minecraft’s encrypted client-server channel, (2) decentralized architecture that enables individual users to run their own servers, and (3) popularity of \"mods\" that add functionality to Minecraft clients and servers. Telepath runs a Minecraft game but substitutes non-disruptive in-game messages with covert content, without changing the game’s interaction with the network manager.We measure performance of Telepath for Web browsing and audio streaming, and show that network traffic generated by Telepath resists statistical traffic analysis that aims to distinguish it from popular Minecraft bots.","PeriodicalId":439989,"journal":{"name":"2023 IEEE Symposium on Security and Privacy (SP)","volume":"78 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2023-05-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"128405157","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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