Authenticated encryption mode for beyond the birthday bound security

In this paper, we propose an authenticated encryption mode for blockciphers. Our authenticated encryption mode, CIP, has provable security bounds which are better than the usual birthday bound security. Besides, the proven security bound for authenticity of CIP is better than any of the previously known schemes. The design is based on the encrypt-then-PRF approach, where the encryption part uses a key stream generation of CENC, and the PRF part combines a hash function based on the inner product and a blockcipher.