Small private keys for systems of multivariate quadratic equations using symmetric cryptography

Systems of Multivariate Quadratic Equations (M Q ) are important in cryptography due to the resistance against attacks that will arise with the advent of quantum computing. Resistant algorithms against attacks based on quantum computing are called post-quantum cryptography. Unbalanced OilVinegar (UOV) is a well known post-quantum signature scheme based on M Q . This paper presents a variation of the implementation of UOV. The proposed and default schemes were implemented in Java using FlexiProvider library, and they were compared with each other. The results present a faster processing time and a reduction in private key size. The proposed implementation was inspired by cryptographic symmetric algorithm RC4 to generate the private key. The size of the private key is independent of the parameters chosen to UOV. Key-words: Multivariate Quadratic Equation, Post-Quantum Cryptography, Unbalanced Oil and Vinegar (UOV), Signature Scheme.