05310999 is referenced by 163 patents and cites 22 patents.

A secure toll payment system is realized by transmitting a changeable encryption code from roadside equipment at a toll plaza to a moving vehicle. Thereafter, the moving vehicle uses it to encrypt payment information according to the Data Encryption Standard algorithm. The moving vehicle transmits the encrypted payment information to the roadside equipment which performs a credit or debit transaction. Because the encryption code changes from time to time, so too does the nature of the signal which is transmitted by the vehicle; and fraud, based on electronic eavesdropping, is substantially eliminated. The encryption code comprises an 8-bit random number and a time/date number. Vehicle-mounted apparatus includes a transponder unit and a portable smart card which inserts therein. The roadside equipment includes a pair of spaced-apart antennas that are sequentially located along an express payment lane at a toll plaza and a computer (Plaza Server) which controls them.

Title
Secure toll collection system for moving vehicles
Application Number
7/908195
Publication Number
5310999
Application Date
July 2, 1992
Publication Date
May 10, 1994
Inventor
Marjorie E Taylor
Carmel
IN, US
Kevin D Murphy
Indianapolis
IN, US
David M Claus
Indianapolis
IN, US
Agent
Michael A Morra
Assignee
AT&T Bell Laboratories
NJ, US
IPC
G07B 15/02
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