3800284 is referenced by 35 patents and cites 3 patents.

An electronic lock system utilizes a function generator at each access point to generate a pair of digitally encoded lock combinations, which, when matched by a digitally encoded lock combination borne by a key, permits access. One of the combinations, when matched, additionally controls the function generator to change the other combination to a next combination based on a pseudo-random number sequence. A central station utilizes a corresponding function generator to appropriately encode the various keys which constitute the sole communication link between the central station and plural access points.

Title
Electronic combination lock and lock system
Application Number
05/323,098
Publication Number
3800284
Application Date
January 12, 1973
Publication Date
March 26, 1974
Inventor
Feinland Seymour
Hinman Bruce E
Eckert Alton B
Zucker Fredric E
Agent
Wittstein Martin D
Scribner Albert W
Soltow Jr William D
Assignee
Pitney Bowes
IPC
G06k 07/06
H04q 03/00
G07C 09/00
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