Patents Examined by Pincuus M. Laufer
  • Patent number: 5870475
    Abstract: In a hybrid fiber-coax distribution network, communications between a central station and particular end stations are encrypted using a working key (WK) of a symmetric encryption scheme. The central station has a public and private key (PPK) of a PPK encryption scheme, and some of the end stations can also each have a respective PPK. To provide secure communications for each end station, if the end station has a PPK, then the respective WK is generated in the central station and communicated, encrypted using the end station's public key (PK), to the end station. Otherwise, the WK is generated in the end station and communicated, encrypted using the central station's PK, to the central station. An individual identifier for each end station, and a cryptographic signature at least for end stations not having a PPK, can be communicated to the central station for authentication of the end stations.
    Type: Grant
    Filed: January 19, 1996
    Date of Patent: February 9, 1999
    Assignee: Northern Telecom Limited
    Inventors: David I. Allan, Liam M. Casey, Adrian D. Jones