OCB: A block-cipher mode of operation for efficient authenticated encryption

摘要: We describe a parallelizable block-cipher mode of operation that simultaneously provides privacy and authenticity. OCB encrypts-and-authenticates nonempty string M ∈ {0, 1}* using ⌈|M|/n⌉ + 2 invocations, where n is the block length underlying cipher. Additional overhead small. refines scheme, IAPM, suggested by Charanjit Jutla. Desirable properties include ability to encrypt bit arbitrary into ciphertext minimal length, cheap offset calculations, key setup, single cryptographic key, no extended-precision addition, nearly optimal number calls, requirement for random IV. prove secure, quantifying adversary's violate mode's or authenticity in terms quality its cipher as pseudorandom permutation (PRP) strong PRP, respectively.