The patent badge is an abbreviated version of the USPTO patent document. The patent badge does contain a link to the full patent document.
The patent badge is an abbreviated version of the USPTO patent document. The patent badge covers the following: Patent number, Date patent was issued, Date patent was filed, Title of the patent, Applicant, Inventor, Assignee, Attorney firm, Primary examiner, Assistant examiner, CPCs, and Abstract. The patent badge does contain a link to the full patent document (in Adobe Acrobat format, aka pdf). To download or print any patent click here.
Patent No.:
Date of Patent:
Sep. 30, 1997
Filed:
Feb. 06, 1995
Mihir Bellare, New York, NY (US);
Phillip W Rogaway, Davis, CA (US);
International Business Machines Corporation, Austin, TX (US);
Abstract
A method for encrypting a plaintext string into ciphertext begins by cipher block chaining (CBC) 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 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 to create the ciphertext. The described mode of operation is length-preserving, yet has the property that related plaintexts give rise to unrelated ciphertexts.