Cryptography for Parallel RAM from Indistinguishability Obfuscation

Abstract

Since many cryptographic schemes are about performing computation on data, it is important to consider a computation model which captures the prominent features of modern system architecture. Parallel random access machine (PRAM) is such an abstraction which not only models multiprocessor platforms, but also new frameworks supporting massive parallel computation such as MapReduce.In this work, we explore the feasibility of designing cryptographic solutions for the PRAM model of computation to achieve security while leveraging the power of parallelism and random data access. We demonstrate asymptotically optimal solutions for a wide-range of cryptographic tasks based on indistinguishability obfuscation. In particular, we construct the first publicly verifiable delegation scheme with privacy in the persistent database setting, which allows a client to privately delegate both computation and data to a server with optimal efficiency. Specifically, the server can perform PRAM computation on private data with parallel efficiency preserved (up to poly-logarithmic overhead). Our results also cover succinct randomized encoding, searchable * A full version is available at encryption, functional encryption, secure multiparty computation, and indistinguishability obfuscation for PRAM.We obtain our results in a modular way through a notion of computational-trace indistinguishability obfuscation (CiO), which may be of independent interests.

Efficient Authenticated Multi-Pattern Matching

“…General-purpose techniques for verifiable computation [19,9,10,20,11,15] and their implementations [30,29] are potential solutions to the problem. To use these systems, the computation of the multi-pattern matching is either modeled as a circuit [28,16] or as a RAM program [14,31,6,7,15]. In circuit-based VC, the whole pattern set must be hardcoded into the circuit, which makes the computation on the server side inefficient (quasi-linear in the circuit size).…”