Menetelmä ja laite salauksen suorittamiseksi käyttäen takaisinkytkettyä rekisteriä, jossa on valittavissa olevat väliotot

• Main Authors: FINKELSTEIN, LOUIS D, PUHL, LARRY C
• Format: Patent
• Language: Finnish; Swedish
• Published: 25.04.1995
• Edition: 6
• Subjects: ADVERTISING; BASIC ELECTRONIC CIRCUITRY; CALCULATING; CODING OR CIPHERING APPARATUS FOR CRYPTOGRAPHIC OR OTHERPURPOSES INVOLVING THE NEED FOR SECRECY; COMPUTING; COUNTING; CRYPTOGRAPHY; DISPLAY; EDUCATION; ELECTRIC COMMUNICATION TECHNIQUE; ELECTRIC DIGITAL DATA PROCESSING; ELECTRICITY; JAMMING OF COMMUNICATION; MULTIPLEX COMMUNICATION; PHYSICS; PULSE TECHNIQUE; SEALS; SECRET COMMUNICATION; TRANSMISSION OF DIGITAL INFORMATION, e.g. TELEGRAPHICCOMMUNICATION; WIRELESS COMMUNICATIONS NETWORKS

A method and apparatus for generating a pseudo-random bit sequence is provided. A first input bit is determined as a function of bits stored in a shift register in accordance with a first feedback algorithm. In addition, a second input bit is determined as a function of bits stored in the shift register in accordance with a second feedback algorithm. Subsequently, a particular input bit to be provided to the shift register is deterministically selected from the group consisting of the first input bit and the second input bit such that a non-linear pseudo random sequence may be produced by the shift register. In addition, a communication unit which utilizes the pseudo-random bit sequence in encrypting a signal to be transmitted and decrypting a received signal is described.