Cryptanalysis of the Authenticated Encryption Algorithm COFFE

COFFE is a hash-based authenticated encryption scheme. In the original paper, it was claimed to have IND-CPA security and also ciphertext integrity even in nonce-misuse scenario. In this paper, we analyse the security of COFFE. Our attack shows that even under the assumption that the primitive hash function is ideal, a valid ciphertext can be forged

• Type: Journal
• Year: 2015
• Where: SACRYPT
• Authors: Ivan Tjuawinata, Tao Huang, Hongjun Wu
• Keywords: Cryptology, SACRYPT 2015