Low-Complexity PIR Using Subfield Subcodes

Abstract

A major drawback of many PIR schemes is the highcomputational cost at the servers. We present a scheme that usesonly operations in the prime field during response generation.For binary extension fields this leads to schemes that only needXOR operations at the servers to calculate the responses. This isachieved by restricting the queries to a subfield subcode or tracecode. We investigate possible parameter ranges and focus on theexample of GRS codes and subfield subcodes of these.