Correlated Pseudorandomness from Expand-Accumulate Codes

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 linear evaluations (VOLE), with low communication cost. We introduce simple new design PCGs based on so-called expand-accumulate codes, which first apply sparse expander graph to replicate each message entry, then accumulate the entries by computing sum prefix. Our offers following advantages compared state-of-the-art PCG constructions: To further improve concrete computational cost, we propose method speeding up full-domain evaluation puncturable function (PPRF). This independently motivated other cryptographic applications PPRFs.