US 5428686
SECURE COMMUNICATION SYSTEM HAVING LONG-TERM KEYING VARIABLE
Assignee
UNITED STATES OF AMERICA, AS REPRESENTED BY THE DIRECTOR, NATIONAL SECURITY AGENCY
Filed
Sep 28, 1981
Granted
Jun 27, 1995
Location
LAUREL MD US
Abstract
A secure communication apparatus incorporates a longterm, non-extractable master key variable which is held in common by all terminals. A pseudorandom bit sequence generator within the transmitter provides a binary bit stream which is transmitted unencrypted to the intended receiver. Both terminals simultaneously mix the master variable with the transmitted pseudorandom bit stream in an identical manner to create a common separate working variable which is subsequently used for data encryption and decryption.
Source: Google Patents
35 USC §181 Secrecy Order
Imposed
Nov 28, 1983
Rescinded
Feb 8, 1995
Duration
11 years, 2 months
Inventor
- 1CARL D. BROWN
Record Details
- Patent number
- US 5428686
- Application
- 06306062
- Aerospace match
- No
- Dataset source
- 35 USC §181 SO records
Back to patent indexSource: USPTO 35 USC §181 secrecy order records