Method and apparatus for preparing and assessing payment documents
On-line verification system for identification card or the like
Location dependence for assuring the security of system-control operations Patent #: 4087856
ApplicationNo. 05/857546 filed on 12/05/1977
US Classes:380/281, Using master key (e.g., key-encrypting-key)340/5.8, Authentication (e.g., identity)380/284, Using master key (e.g., key-encrypting-key)380/45, Multiple key level705/71, Including key management713/155Central trusted authority provides computer authentication
ExaminersPrimary: Birmiel, Howard A.
Attorney, Agent or Firm
International ClassesH04L 9/18 (20060101)
G07F 7/10 (20060101)
AbstractIn a data communication network providing communication security for communication sessions between a first station and a second station where each station has cryptographic apparatus provided with an operational key which should be common to both stations for cryptographic operations, an operational key verification arrangement is provided in which a first number provided at the first station is operated upon in accordance with the first station operational key to obtain cryptographic data for transmission to the second station, requiring the second station to perform an operation on the first station cryptographic data in accordance with the second station operational key to obtain cryptographic data for transmission back to the first station and performing an operation at the first station in accordance with the first number and the second station cryptographic data to verify that the second station is the source of second station cryptographic data only if the operational keys are identical.