Inner-Product Functional Encryption from Random Linear Codes: Trial and Challenges

Inner-product encryption scheme is an important branch of functional encryption schemes, which has wide applications in modern society. There have existed many inner-product encryption schemes, but as far as we know, no code-based inner-product functional encryption scheme has been proposed. As one of the most popular post-quantum cryptographic techniques, why code-based cryptosystems are seldom applied in these areas raises our concern. In this paper, we build an inner product encryption scheme from random linear codes and prove its security. Unfortunately, our scheme still suffers from the so large parameter size, which indicates that how to build a practical code-based functional encryption scheme remains a challenging problem.