A Secure Variant of the SRP Encryption Scheme with Shorter Private Key

Abstract

The study of multivariate encryption algorithm is an important topic of multivariate public key cryptography research. However, quite few secure and practical multivariate encryption algorithms have been found up to now. The SRP encryption scheme is a multivariate encryption scheme that combines Square, Rainbow and the Plus method technique, which is of high efficiency and resistant to existing known attacks against multivariate schemes. In this paper, an improved SRP scheme with shorter private key and higher decryption efficiency is proposed. We introduce rotation relations into parts of the private key, which enables us to reduce the private key size by about 61%. And the decryption speed is 2.1 times faster than that of the original SRP. In terms of theory and experiment, we analyze the security of the improved SRP for several attacks against SRP. The results show that our modifications do not weaken the security of the original schemes.