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HEtest: a homomorphic encryption testing framework

January 30, 2015
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Conference Paper
Author:
Mayank H. Varia
…
Published in:
3rd Workshop on Encrypted Computing and Applied Homomorphic Cryptography (WAHC 2015), 30 January 2015.
Topic:
systems analysis
R&D area:
R&D group:

Summary

In this work, we present a generic open-source software framework that can evaluate the correctness and performance of homomorphic encryption software. Our framework, called HEtest, automates the entire process of a test: generation of data for testing (such as circuits and inputs), execution of a test, comparison of performance to an insecure baseline, statistical analysis of the test results, and production of a LaTeX report. To illustrate the capability of our framework, we present a case study of our analysis of the open-source HElib homomorphic encryption software. We stress though that HEtest is written in a modular fashion, so it can easily be adapted to test any homomorphic encryption software.
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Summary

In this work, we present a generic open-source software framework that can evaluate the correctness and performance of homomorphic encryption software. Our framework, called HEtest, automates the entire process of a test: generation of data for testing (such as circuits and inputs), execution of a test, comparison of performance to...

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HEtest: a homomorphic encryption testing framework

Automated assessment of secure search systems

January 20, 2015
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Journal Article
Author:
Mayank H. Varia
…
Published in:
ACM SIGOPS Operating Systems Review, Vol. 49, No. 1, 20 January 2015, pp. 22-30.
Topic:
systems analysis
R&D area:
R&D group:

Summary

This work presents the results of a three-year project that assessed nine different privacy-preserving data search systems. We detail the design of a software assessment framework that focuses on low system footprint, repeatability, and reusability. A unique achievement of this project was the automation and integration of the entire test process, from the production and execution of tests to the generation of human-readable evaluation reports. We synthesize our experiences into a set of simple mantras that we recommend following in the design of any assessment framework.
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Summary

This work presents the results of a three-year project that assessed nine different privacy-preserving data search systems. We detail the design of a software assessment framework that focuses on low system footprint, repeatability, and reusability. A unique achievement of this project was the automation and integration of the entire test...

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Automated assessment of secure search systems

Information leaks without memory disclosures: remote side channel attacks on diversified code

November 3, 2014
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Conference Paper
Author:
Hamed Okhravi
…
Published in:
CCS 2014: Proc. of the ACM Conf. on Computer and Communications Security, 3-7 November 2014.
Topic:
systems analysis
R&D area:
R&D group:

Summary

Code diversification has been proposed as a technique to mitigate code reuse attacks, which have recently become the predominant way for attackers to exploit memory corruption vulnerabilities. As code reuse attacks require detailed knowledge of where code is in memory, diversification techniques attempt to mitigate these attacks by randomizing what instructions are executed and where code is located in memory. As an attacker cannot read the diversified code, it is assumed he cannot reliably exploit the code. In this paper, we show that the fundamental assumption behind code diversity can be broken, as executing the code reveals information about the code. Thus, we can leak information without needing to read the code. We demonstrate how an attacker can utilize a memory corruption vulnerability to create side channels that leak information in novel ways, removing the need for a memory disclosure vulnerability. We introduce seven new classes of attacks that involve fault analysis and timing side channels, where each allows a remote attacker to learn how code has been diversified.
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Summary

Code diversification has been proposed as a technique to mitigate code reuse attacks, which have recently become the predominant way for attackers to exploit memory corruption vulnerabilities. As code reuse attacks require detailed knowledge of where code is in memory, diversification techniques attempt to mitigate these attacks by randomizing what...

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Information leaks without memory disclosures: remote side channel attacks on diversified code

Quantitative evaluation of dynamic platform techniques as a defensive mechanism

September 17, 2014
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Conference Paper
Author:
Hamed Okhravi
…
Published in:
RAID 2014: 17th Int. Symp. on Research in Attacks, Intrusions, and Defenses, 17-19 September 2014.
Topic:
systems analysis
R&D area:
R&D group:

Summary

Cyber defenses based on dynamic platform techniques have been proposed as a way to make systems more resilient to attacks. These defenses change the properties of the platforms in order to make attacks more complicated. Unfortunately, little work has been done on measuring the effectiveness of these defenses. In this work, we first measure the protection provided by a dynamic platform technique on a testbed. The counter-intuitive results obtained from the testbed guide us in identifying and quantifying the major effects contributing to the protection in such a system. Based on the abstract effects, we develop a generalized model of dynamic platform techniques which can be used to quantify their effectiveness. To verify and validate out results, we simulate the generalized model and show that the testbed measurements and the simulations match with small amount of error. Finally, we enumerate a number of lessons learned in our work which can be applied to quantitative evaluation of other defensive techniques.
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Summary

Cyber defenses based on dynamic platform techniques have been proposed as a way to make systems more resilient to attacks. These defenses change the properties of the platforms in order to make attacks more complicated. Unfortunately, little work has been done on measuring the effectiveness of these defenses. In this...

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Quantitative evaluation of dynamic platform techniques as a defensive mechanism

A survey of cryptographic approaches to securing big-data analytics in the cloud

September 9, 2014
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Conference Paper
Author:
Sophia Yakoubov
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Published in:
HPEC 2014: IEEE Conf. on High Performance Extreme Computing, 9-11 September 2014.
Topic:
supercomputing
R&D area:
R&D group:

Summary

The growing demand for cloud computing motivates the need to study the security of data received, stored, processed, and transmitted by a cloud. In this paper, we present a framework for such a study. We introduce a cloud computing model that captures a rich class of big-data use-cases and allows reasoning about relevant threats and security goals. We then survey three cryptographic techniques - homomorphic encryption, verifiable computation, and multi-party computation - that can be used to achieve these goals. We describe the cryptographic techniques in the context of our cloud model and highlight the differences in performance cost associated with each.
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Summary

The growing demand for cloud computing motivates the need to study the security of data received, stored, processed, and transmitted by a cloud. In this paper, we present a framework for such a study. We introduce a cloud computing model that captures a rich class of big-data use-cases and allows...

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A survey of cryptographic approaches to securing big-data analytics in the cloud

A test-suite generator for database systems

September 9, 2014
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Conference Paper
Author:
Ariel T. Hamlin
…
Published in:
HPEC 2014: IEEE Conf. on High Performance Extreme Computing, 9-11 September 2014.
Topic:
systems analysis
R&D area:
R&D group:

Summary

In this paper, we describe the SPAR Test Suite Generator (STSG), a new test-suite generator for SQL style database systems. This tool produced an entire test suite (data, queries, and ground-truth answers) as a unit and in response to a user's specification. Thus, database evaluators could use this tool to craft test suites for particular aspects of a specific database system. The inclusion of ground-truth answers in the produced test suite, furthermore, allowed this tool to support both benchmarking (at various scales) and correctness-checking in a repeatable way. Lastly, the test-suite generator of this document was extensively profiled and optimized, and was designed for test-time agility.
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Summary

In this paper, we describe the SPAR Test Suite Generator (STSG), a new test-suite generator for SQL style database systems. This tool produced an entire test suite (data, queries, and ground-truth answers) as a unit and in response to a user's specification. Thus, database evaluators could use this tool to...

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A test-suite generator for database systems

Systematic analysis of defenses against return-oriented programming

October 23, 2013
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Conference Paper
Author:
Richard W. Skowyra
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Published in:
RAID 2013: 16th Int. Symp. on Research in Attacks, Intrusions, and Defenses, LNCS 8145, 23-25 October 2013.
Topic:
systems analysis
R&D area:
R&D group:

Summary

Since the introduction of return-oriented programming, increasingly compiles defenses and subtle attacks that bypass them have been proposed. Unfortunately the lack of a unifying threat model among code reuse security papers makes it difficult to evaluate the effectiveness of defenses, and answer critical questions about the interoperability, composability, and efficacy of existing defensive techniques. For example, what combination of defenses protect against every known avenue of code reuse? What is the smallest set of such defenses? In this work, we study the space of code reuse attacks by building a formal model of attacks and their requirements, and defenses and their assumptions. We use a SAT solver to perform scenario analysis on our model in two ways. First, we analyze the defense configurations of a real-world system. Second, we reason about hypothetical defense bypasses. We prove by construction that attack extensions implementing the hypothesized functionality are possible even if a 'perfect' version of the defense is implemented. Our approach can be used to formalize the process of threat model definition, analyze defense configurations, reason about composability and efficacy, and hypothesize about new attacks and defenses.
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Summary

Since the introduction of return-oriented programming, increasingly compiles defenses and subtle attacks that bypass them have been proposed. Unfortunately the lack of a unifying threat model among code reuse security papers makes it difficult to evaluate the effectiveness of defenses, and answer critical questions about the interoperability, composability, and efficacy...

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Systematic analysis of defenses against return-oriented programming

Continuous security metrics for prevalent network threats - introduction and first four metrics

May 22, 2012
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Project Report
Author:
Richard P. Lippmann
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Published in:
MIT Lincoln Laboratory Report IA-3
Topic:
systems analysis
R&D area:
R&D group:

Summary

The goal of this work is to introduce meaningful security metrics that motivate effective improvements in network security. We present a methodology for directly deriving security metrics from realistic mathematical models of adversarial behaviors and systems and also a maturity model to guide the adoption and use of these metrics. Four security metrics are described that assess the risk from prevalent network threats. These can be computed automatically and continuously on a network to assess the effectiveness of controls. Each new metric directly assesses the effect of controls that mitigate vulnerabilities, continuously estimates the risk from one adversary, and provides direct insight into what changes must be made to improve security. Details of an explicit maturity model are provided for each metric that guide security practitioners through three stages where they (1) Develop foundational understanding, tools and procedures, (2) Make accurate and timely measurements that cover all relevant network components and specify security conditions to test, and (3) Perform continuous risk assessments and network improvements. Metrics are designed to address specific threats, maintain practicality and simplicity, and motivate risk reduction. These initial four metrics and additional ones we are developing should be added incrementally to a network to gradually improve overall security as scores drop to acceptable levels and the risks from associated cyber threats are mitigated.
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Summary

The goal of this work is to introduce meaningful security metrics that motivate effective improvements in network security. We present a methodology for directly deriving security metrics from realistic mathematical models of adversarial behaviors and systems and also a maturity model to guide the adoption and use of these metrics...

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Continuous security metrics for prevalent network threats - introduction and first four metrics

Dedicated vs. distributed: a study of mission survivability metrics

November 7, 2011
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Conference Paper
Author:
Hamed Okhravi
…
Published in:
MILCOM 2011, IEEE Military Communications Conf., 7-10 November 2011, pp. 1345-1350.
Topic:
systems analysis
R&D area:
R&D group:

Summary

A traditional trade-off when designing a mission critical network is whether to deploy a small, dedicated network of highly reliable links (e.g. dedicated fiber) or a largescale, distributed network of less reliable links (e.g. a leased line over the Internet). In making this decision, metrics are needed that can express the reliability and security of these networks. Previous work on this topic has widely focused on two approaches: probabilistic modeling of network reliabilities and graph theoretic properties (e.g. minimum cutset). Reliability metrics do not quantify the robustness, the ability to tolerate multiple link failures, in a distributed network. For example, a fully redundant network and a single link can have the same overall source-destination reliability (0.9999), but they have very different robustness. Many proposed graph theoretic metrics are also not sufficient to capture network robustness. Two networks with identical metric values (e.g. minimum cutset) can have different resilience to link failures. More importantly, previous efforts have mainly focused on the source-destination connectivity and in many cases it is difficult to extend them to a general set of requirements. In this work, we study network-wide metrics to quantitatively compare the mission survivability of different network architectures when facing malicious cyber attacks. We define a metric called relative importance (RI), a robustness metric for mission critical networks, and show how it can be used to both evaluate mission survivability and make recommendations for its improvement. Additionally, our metric can be evaluated for an arbitrarily general set of mission requirements. Finally, we study the probabilistic and deterministic algorithms to quantify the RI metric and empirically evaluate it for sample networks.
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Summary

A traditional trade-off when designing a mission critical network is whether to deploy a small, dedicated network of highly reliable links (e.g. dedicated fiber) or a largescale, distributed network of less reliable links (e.g. a leased line over the Internet). In making this decision, metrics are needed that can express...

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Dedicated vs. distributed: a study of mission survivability metrics

Virtuoso: narrowing the semantic gap in virtual machine introspection

May 22, 2011
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Conference Paper
Author:
Brendan F. Dolan-Gavitt
…
Published in:
2011 IEEE Symp. on Security and Privacy, 22-25 May 2011, pp. 297-312.
Topic:
cyber security
R&D area:
R&D group:

Summary

Introspection has featured prominently in many recent security solutions, such as virtual machine-based intrusion detection, forensic memory analysis, and low-artifact malware analysis. Widespread adoption of these approaches, however, has been hampered by the semantic gap: in order to extract meaningful information about the current state of a virtual machine, detailed knowledge of the guest operating system's inner workings is required. In this paper, we present a novel approach for automatically creating introspection tools for security applications with minimal human effort. By analyzing dynamic traces of small, in-guest programs that compute the desired introspection information, we can produce new programs that retrieve the same information from outside the guest virtual machine. We demonstrate the efficacy of our techniques by automatically generating 17 programs that retrieve security information across 3 different operating systems, and show that their functionality is unaffected by the compromise of the guest system. Our technique allows introspection tools to be effortlessly generated for multiple platforms, and enables the development of rich introspection-based security applications.
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Summary

Introspection has featured prominently in many recent security solutions, such as virtual machine-based intrusion detection, forensic memory analysis, and low-artifact malware analysis. Widespread adoption of these approaches, however, has been hampered by the semantic gap: in order to extract meaningful information about the current state of a virtual machine, detailed...

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Virtuoso: narrowing the semantic gap in virtual machine introspection
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