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Don't even ask: database access control through query control

Summary

This paper presents a vision and description for query control, which is a paradigm for database access control. In this model, individual queries are examined before being executed and are either allowed or denied by a pre-defined policy. Traditional view-based database access control requires the enforcer to view the query, the records, or both. That may present difficulty when the enforcer is not allowed to view database contents or the query itself. This discussion of query control arises from our experience with privacy-preserving encrypted databases, in which no single entity learns both the query and the database contents. Query control is also a good fit for enforcing rules and regulations that are not well-addressed by view-based access control. With the rise of federated database management systems, we believe that new approaches to access control will be increasingly important.
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Summary

This paper presents a vision and description for query control, which is a paradigm for database access control. In this model, individual queries are examined before being executed and are either allowed or denied by a pre-defined policy. Traditional view-based database access control requires the enforcer to view the query...

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SoK: cryptographically protected database search

Summary

Protected database search systems cryptographically isolate the roles of reading from, writing to, and administering the database. This separation limits unnecessary administrator access and protects data in the case of system breaches. Since protected search was introduced in 2000, the area has grown rapidly, systems are offered by academia, start-ups, and established companies. However, there is no best protected search system or set of techniques. Design of such systems is a balancing act between security, functionality, performance, and usability. This challenge is made more difficult by ongoing database specialization, as some users will want the functionality of SQL, NoSQL, or NewSQL databases. This database evolution will continue, and the protected search community should be able to quickly provide functionality consistent with newly invented databases. At the same time, the community must accurately and clearly characterize the tradeoffs between different approaches. To address these challenges, we provide the following contributions:(1) An identification of the important primitive operations across database paradigms. We find there are a small number of base operations that can be used and combined to support a large number of database paradigms.(2) An evaluation of the current state of protected search systems in implementing these base operations. This evaluation describes the main approaches and tradeoffs for each base operation. Furthermore, it puts protected search in the context of unprotected search, identifying key gaps in functionality.(3) An analysis of attacks against protected search for different base queries.(4) A roadmap and tools for transforming a protected search system into a protected database, including an open-source performance evaluation platform and initial user opinions of protected search.
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Summary

Protected database search systems cryptographically isolate the roles of reading from, writing to, and administering the database. This separation limits unnecessary administrator access and protects data in the case of system breaches. Since protected search was introduced in 2000, the area has grown rapidly, systems are offered by academia, start-ups...

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Cryptography for Big Data security

Published in:
Chapter 10 in Big Data: Storage, Sharing, and Security, 2016, pp. 214-87.

Summary

This chapter focuses on state-of-the-art provably secure cryptographic techniques for protecting big data applications. We do not focus on more established, and commonly available cryptographic solutions. The goal is to inform practitioners of new techniques to consider as they develop new big data solutions rather than to summarize the current best practice for securing data.
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Summary

This chapter focuses on state-of-the-art provably secure cryptographic techniques for protecting big data applications. We do not focus on more established, and commonly available cryptographic solutions. The goal is to inform practitioners of new techniques to consider as they develop new big data solutions rather than to summarize the current...

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Unifying leakage classes: simulatable leakage and pseudoentropy

Published in:
8th Int. Conf. Information-Theoretic Security (ICITS 2015), 2-5 May 2015 in Lecture Notes in Computer Science (LNCS), Vol. 9063, 2015, pp. 69-86.

Summary

Leakage resilient cryptography designs systems to withstand partial adversary knowledge of secret state. Ideally, leakage-resilient systems withstand current and future attacks; restoring confidence in the security of implemented cryptographic systems. Understanding the relation between classes of leakage functions is an important aspect. In this work, we consider the memory leakage model, where the leakage class contains functions over the system's entire secret state. Standard limitations include functions over the system's entire secret state. Standard limitations include functions with bounded output length, functions that retain (pseudo) entropy in the secret, and functions that leave the secret computationally unpredictable. Standaert, Pereira, and Yu (Crypto, 2013) introduced a new class of leakage functions they call simulatable leakage. A leakage function is simulatable if a simulator can produce indistinguishable leakage without access to the true secret state. We extend their notion to general applications and consider two versions. For weak simulatability: the simulated leakage must be indistinguishable from the true leakage in the presence of public information. For strong simulatability, this requirement must also hold when the distinguisher has access to the true secret state. We show the following: --Weakly simulatable functions retain computational unpredictability. --Strongly simulatability functions retain pseudoentropy. --There are bounded length functions that are not weakly simulatable. --There are weakly simulatable functions that remove pseudoentropy. --There are leakage functions that retain computational unpredictability are not weakly simulatable.
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Summary

Leakage resilient cryptography designs systems to withstand partial adversary knowledge of secret state. Ideally, leakage-resilient systems withstand current and future attacks; restoring confidence in the security of implemented cryptographic systems. Understanding the relation between classes of leakage functions is an important aspect. In this work, we consider the memory leakage...

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Automated assessment of secure search systems

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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A test-suite generator for database systems

Published in:
HPEC 2014: IEEE Conf. on High Performance Extreme Computing, 9-11 September 2014.

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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