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.

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