05917913 is referenced by 334 patents and cites 8 patents.

A portable electronic authorization device for approving a transaction request originated from an electronic transaction system. The portable electronic authorization device includes first logic circuit configured to receive first digital data representative of the transaction request. There is further included second logic circuit configured to form second digital data responsive to the transaction request received by the first logic circuit if the transaction request is approved by a user of the portable electronic transaction device. The second digital data represents encrypted data signifying an approval by the user of the transaction request. Additionally, the portable electronic authorization device includes transmission circuitry coupled to the second logic circuit. The transmission circuitry is configured to transmit the second digital data from the portable electronic authorization apparatus to the electronic transaction system if the user approves the transaction request.

Title
Portable electronic authorization devices and methods therefor
Application Number
8/759555
Publication Number
5917913
Application Date
December 4, 1996
Publication Date
June 29, 1999
Inventor
Ynjiun Paul Wang
20350 Stevens Creek Blvd., Apt 510, Cupertino, 95014
CA, US
Agent
Beyer & Weaver
IPC
H04K 1/00
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