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This patent was reissued on Apr. 6 , 1999 as patent
USRE36181
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 Title: |
US5363448:
Pseudorandom number generation and cryptographic authentication
[ Derwent Title ]
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| Country: |
US United States of America
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| Inventor: |
Koopman, Jr., Philip J.; Hebron, CT
Finn, Alan M.; Amston, CT
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| Assignee: |
United Technologies Automotive, Inc., Dearborn, MI
other patents from UNITED TECHNOLOGIES AUTOMOTIVE, INC. (597540) (approx. 411)
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| Published / Filed: |
1994-11-08
/ 1993-06-30
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| Application Number: |
US1993000086080
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| IPC Code: |
Advanced:
E05B 49/00;
E05B 65/20;
G06F 7/58;
G07C 9/00;
G09C 1/00;
H04L 9/20;
H04L 9/32;
Core:
H04L 9/18;
more...
IPC-7:
H04L 9/32;
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| ECLA Code: |
G06F7/58P1; G07C9/00E2; H04L9/32B;
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| U.S. Class: |
Current:
713/170;
340/005.26;
340/005.8;
380/043;
380/262;
380/274;
713/169;
Original:
380/023;
380/021;
380/025;
380/043;
380/049;
340/825.31;
340/825.34;
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| Field of Search: |
380/004,9,23,24,25,46,49,50,21,43
331/078
364/717
340/825.31,825.34
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| Priority Number: |
| 1993-06-30 |
US1993000086080 |
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| Abstract: |
An automobile door lock receiver module (30) and a plurality of keychain fob transmitter units (16) contain identification numbers, secret initial values, and secret feedback masks so as to authenticate encrypted messages from any of the assigned fobs, indicative of commands registered by closing switches on the fob. Each fob is synchronized with the receiving module by means of a truly random number concatenated with a secret initial value and encrypted, through a linear feedback shift register or other operations. A second secret initial value is encrypted and command bits are exclusive ORed into the low order bit positions; the two encrypted numbers are concatenated and encrypted to form a key word which is transmitted with the fob ID. Synchronization includes decrypting to recover the truly random number and the secret initial value concatenated therewith; the truly random number is compared with previously received random numbers in order to avoid copying of recently transmitted synchronization commands. Successive lock-related commands utilize the number encrypted from the truly random number and the second secret initial value as starting values, employing a pseudorandom number of encryption iterations. A half-second delay between responses mitigates gaining access through numerical trials. An authenticated panic alarm command operates the headlights and horn of the vehicle but does not alter the synchronization.
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| Attorney, Agent or Firm: |
Williams, M. P. ;
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| Primary / Asst. Examiners: |
Gregory, Bernarr E.;
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| INPADOC Legal Status: |
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| Designated Country: |
CA EP JP DE ES FR GB IT SE
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| Family: |
Show 15 known family members
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First Claim:
Show all 46 claims |
We claim:
1. A method of cryptographic authentication of transmissions from a transmitting unit to a receiving module,
- comprising, in said transmitting unit:
- separately generating a plurality of pseudorandom numbers;
- concatenating said numbers to form a combined word;
- performing an encryption operation on said combined word; and
- transmitting a command word including a key portion derived from the result of said encryption operation; and
- comprising, in said receiving module:
- receiving said command word;
- performing a decryption operation on the key portion of said command word to recover said combined word;
- providing at least one number; and
- providing an authentication signal only if at least a portion of said at least one number is identical to a corresponding portion of said recovered combined word.
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| Background / Summary: |
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| Drawing Descriptions: |
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| Description: |
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| Forward References: |
Show 81 U.S. patent(s) that reference this one
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