Computer key and computer lock system
Random number generator using sampled output of variable frequency oscillator
Integrated circuit random number generator using sampled output of variable frequency oscillator
Communications network using IC cards
Electronic key locking circuitry
Time-key integrated circuit Patent #: 5010331
ApplicationNo. 615606 filed on 11/19/1990
US Classes:705/55, Requiring a supplemental attachment or input (e.g., dongle) to open340/5.26, Code rotating or scrambling340/5.54, Password340/5.65, Electronic coded record380/46Nonlinear (e.g., pseudorandom)
ExaminersPrimary: Anderson, Lawrence E.
Assistant: Ellis, Richard L.
Attorney, Agent or Firm
International ClassG06F 012/14
AbstractAn electronic key which includes a pseudo-random number generator. If the correct password is received, the contents of a secure memory will be outputted by the electronic key. However, if an incorrect password is received, that password will be used as a seed value for the pseudo-random number generator, and the resulting value will be outputted.Thus, if a copier exercises the key through all possible passwords, the incorrect passwords, as well as the correct password, will result in the same output data every time it is tried.