Abstract:

A novel scheme based on traditional electronic codebook (ECB) mode was proposed to improve the capability of block cipher mode of operation. Message blocks were masked with the Gray code so that the data mode was hidden efficiently. The security of the scheme was analyzed in the sense of reduction based cryptography. Investigation shows that the scheme is left or right indistinguishable against chosen plaintext attack (LOR CPA) secure if the underlying block cipher is a pseudorandom permutation.

Key words: block cipher, mode of operation, provable security, advantage function