公开(公告)号：DE69618040D1

公开(公告)日：2002-01-31

申请号：DE69618040

申请日：1996-01-25

Applicant: IBM

Inventor： BELLARE MIHIR ,  ROGAWAY PHILLIP W

IPC: G09C1/00 ,  H04L9/06 ,  H04L9/32

Abstract: A method for encrypting a plaintext string into ciphertext begins by cipher block chaining (CBC) (70) the plaintext using a first key and a null initialization vector to generate a CBC message authentication code (MAC) whose length is equal to the block length. The plaintext string is then cipher block chained (72) again, now using a second key and the CBC-MAC as the initialization vector, to generate an enciphered string. The CBC-MAC and a prefix of the enciphered string comprising all of the enciphered string except the last block are then combined (74) to create the ciphertext. The described mode of operation is length-preserving, yet has the property that related plaintexts give rise to unrelated ciphertexts.

公开(公告)号：DE69618040T2

公开(公告)日：2002-08-29

申请号：DE69618040

申请日：1996-01-25

Applicant: IBM

Inventor： BELLARE MIHIR ,  ROGAWAY PHILLIP W

IPC: G09C1/00 ,  H04L9/06 ,  H04L9/32

Abstract: A method for encrypting a plaintext string into ciphertext begins by cipher block chaining (CBC) (70) the plaintext using a first key and a null initialization vector to generate a CBC message authentication code (MAC) whose length is equal to the block length. The plaintext string is then cipher block chained (72) again, now using a second key and the CBC-MAC as the initialization vector, to generate an enciphered string. The CBC-MAC and a prefix of the enciphered string comprising all of the enciphered string except the last block are then combined (74) to create the ciphertext. The described mode of operation is length-preserving, yet has the property that related plaintexts give rise to unrelated ciphertexts.