CryptoDB
Nicolas Resch
Publications
Year
Venue
Title
2022
CRYPTO
Correlated Pseudorandomness from Expand-Accumulate Codes
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Abstract
A pseudorandom correlation generator (PCG) is a recent tool for securely generating useful sources of correlated randomness, such as random oblivious transfers (OT) and vector oblivious linear evaluations (VOLE), with low communication cost.
We introduce a simple new design for PCGs based on so-called expand-accumulate codes, which first apply a sparse random expander graph to replicate each message entry, and then accumulate the entries by computing the sum of each prefix. Our design offers the following advantages compared to state-of-the-art PCG constructions:
- Competitive concrete efficiency backed by provable security against relevant classes of attacks;
- An offline-online mode that combines near-optimal cache-friendliness with simple parallelization;
- Concretely efficient extensions to pseudorandom correlation functions, which enable incremental generation of new correlation instances on demand, and to new kinds of correlated randomness that include circuit-dependent correlations.
To further improve the concrete computational cost, we propose a method for speeding up a full-domain evaluation of a puncturable pseudorandom function (PPRF). This is independently motivated by other cryptographic applications of PPRFs.
Coauthors
- Elette Boyle (1)
- Geoffroy Couteau (1)
- Niv Gilboa (1)
- Yuval Ishai (1)
- Lisa Kohl (1)
- Peter Scholl (1)