Verifiable Oblivious Storage

Apon, Daniel; Katz, Jonathan; Shi, Elaine; Thiruvengadam, Aishwarya

doi:10.1007/978-3-642-54631-0_8

Cited by 51 publications

(42 citation statements)

References 35 publications

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“…In MVC, the authors prove soundness against untrusted server, and privacy against a malicious client that may collude with the server. Apon et al formalized the notion of verifiable oblivious storage that allows a client to outsource the data to an untrusted server while ensuring privacy, obliviousness and verifiability [89].…”

Section: Problem Definition (Vc)mentioning

confidence: 99%

Primitives towards verifiable computation: a survey

Ahmad

Wang

Hong

et al. 2018

Front. Comput. Sci.

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Verifiable computation (VC) paradigm has got the captivation that in real term is highlighted by the concept of third party computation. In more explicate terms, VC allows resource constrained clients/organizations to securely outsource expensive computations to untrusted service providers, while acquiring the publicly or privately verifiable results. Many mainstream solutions have been proposed to address the diverse problems within the VC domain. Some of them imposed assumptions over performed computations, while the others took advantage of interactivity /non-interactivity, zero knowledge proofs, and arguments. Further proposals utilized the powers of probabilistic checkable or computationally sound proofs. In this survey, we present a chronological study and classify the VC proposals based on their adopted domains. First, we provide a broader overview of the theoretical advancements while critically analyzing them. Subsequently, we present a comprehensive view of their utilization in the state of the art VC approaches. Moreover, a brief overview of recent proof based VC systems is also presented that lifted up the VC domain to the verge of practicality. We use the presented study and reviewed results to identify the similarities and alterations, modifications, and hybridization of different approaches, while comparing their advantages and reporting their overheads. Finally, we discuss implementation of such VC based systems, their applications, and the likely future directions.

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Section: Problem Definition (Vc)mentioning

confidence: 99%

Primitives towards verifiable computation: a survey

Ahmad

Wang

Hong

et al. 2018

Front. Comput. Sci.

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“…However, in a two-party protocol the client can never prove after the fact that the server stopped responding. 1 One obvious solution is to route communication through the verifier, who can confirm that the client's request was sent and that the server did not respond. This, however, requires the verifier to participate in every access.…”

Section: Externally Verifiable Orammentioning

confidence: 99%

“…Previous work has introduced the idea of verifiable oblivious storage [1]. (Here "oblivious storage" is used to mean an ORAM protocol where the server can perform computation, rather than simply storing data.…”

Section: Introductionmentioning

confidence: 99%

Externally Verifiable Oblivious RAM

Gancher

Groce

Ledger

2017

Proceedings on Privacy Enhancing Technologies

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Abstract:We present the idea of externally verifiable oblivious RAM (ORAM). Our goal is to allow a client and server carrying out an ORAM protocol to have disputes adjudicated by a third party, allowing for the enforcement of penalties against an unreliable or malicious server. We give a security definition that guarantees protection not only against a malicious server but also against a client making false accusations. We then give modifications of the Path ORAM [15] and Ring ORAM [9] protocols that meet this security definition. These protocols both have the same asymptotic runtimes as the semi-honest original versions and require the external verifier to be involved only when the client or server deviates from the protocol. Finally, we implement externally verified ORAM, along with an automated cryptocurrency contract to use as the external verifier.

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“…By comparison, the original PosMap representation (up to § 4) only achieves X = 16 for ORAM tree depths of L = 17 to L = 32. 2 We restrict X to be a power of two to simplify the PosMap block address translation from § 3.2.…”

Section: Benefit Of Compressed Format (In Practice)mentioning

confidence: 99%

“…Merkle tree constructions [2,25] need to integrity verify all the blocks on the path to check/update the root hash. Crucially, our PM-MAC construction only needs to integrity verify (check and update) 1 block -namely the block of interest -per access, achieving an asympotic reduction in hash bandwidth.…”

Section: Key Advantage: Hash Bandwidth and Parallelismmentioning

confidence: 99%

Freecursive ORAM

Fletcher

Ren

Kwon

et al. 2015

Proceedings of the Twentieth International Conference on Architectural Support for Programming Languages and Operating Systems

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Oblivious RAM (ORAM) is a cryptographic primitive that hides memory access patterns as seen by untrusted storage. Recently, ORAM has been architected into secure processors. A big challenge for hardware ORAM schemes is how to efficiently manage the Position Map (PosMap), a central component in modern ORAM algorithms. Implemented naïvely, the PosMap causes ORAM to be fundamentally unscalable in terms of on-chip area. On the other hand, a technique called Recursive ORAM fixes the area problem yet significantly increases ORAM's performance overhead.To address this challenge, we propose three new mechanisms. We propose a new ORAM structure called the PosMap Lookaside Buffer (PLB) and PosMap compression techniques to reduce the performance overhead from Recursive ORAM empirically (the latter also improves the construction asymptotically). Through simulation, we show that these techniques reduce the memory bandwidth overhead needed to support recursion by 95%, reduce overall ORAM bandwidth by 37% and improve overall SPEC benchmark performance by 1.27×. We then show how our PosMap compression techniques further facilitate an extremely efficient integrity verification scheme for ORAM which we call PosMap MAC (PMMAC). For a practical parameterization, PMMAC reduces the amount of hashing needed for integrity checking by ≥ 68× relative to prior schemes and introduces only 7% performance overhead.We prototype our mechanisms in hardware and report area and clock frequency for a complete ORAM design postsynthesis and post-layout using an ASIC flow in a 32 nm commercial process. With 2 DRAM channels, the design post-layout runs at 1 GHz and has a total area of .47 mm 2 . Depending on PLB-specific parameters, the PLB accounts for 10% to 26% area. PMMAC costs 12% of total design area. Our work is the first to prototype Recursive ORAM or ORAM with any integrity scheme in hardware.

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Verifiable Oblivious Storage

Cited by 51 publications

References 35 publications

Primitives towards verifiable computation: a survey

Primitives towards verifiable computation: a survey

Externally Verifiable Oblivious RAM

Freecursive ORAM

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