Study On Security Of NTRU Public Key Cryptosystem And Its Application

As a newly fast public key cryptosystem, much attention has been paid to this cryptosystem. NTRU is one of the fastest public key cryptosystem at present. Because of its good characteristic, it has been considered by the Consortium for Efficient Embedded Security and IEEE P1363 Working Group for Standards In Public Key Cryptography. This paper focus on the NTRU public key cryptosystem including its implement performance, security analysis and its application. The main contributions of this paper are: 1. present a decipherable ciphertext attack on the optimized NTRU public key cryptosystem, and conclude that there is possibility that partial information leakage of the secret key will happen when we choose N=503 in the parameter advised in optimized NTRU version. 2. propose the secret sharing NTRU public-key cryptosystem based on Brickell's secret sharing scheme, and our scheme is proven to achieve IND-CCA in the random oracle model after introducing the concept of twin-encryption.