Patents by Inventor Michael A. Bobbitt

Michael A. Bobbitt has filed for patents to protect the following inventions. This listing includes patent applications that are pending as well as patents that have already been granted by the United States Patent and Trademark Office (USPTO).

  • Patent number: 6940979
    Abstract: Management of ciphertext devaluation in public key infrastructure is addressed by providing system and method using a certificate having a validity dependent on the amount of ciphertext associated with the certificate, i.e. a ciphertext limited certificate (CLC). Thus when the amount of ciphertext reaches or exceeds a predetermined value, the certificate is invalid. The CCE may be expressed as a non critical extension to a X.509 certificate to allow for interoperability with conventional validity conditions based on validity period or revocation. Ciphertext limited certificates may be implemented in an X.509 standard environment based on a method of assigning and determining a certificate ciphertext entitlement (CCE), calculating a generated Ciphertext index (CGI) and performing a CCE threshold detection, and when the GCI reaches or exceeds the CCE, causing a key update, e.g. a rollover of the certificate. Assurance levels may be set based on assigning different CCE default values.
    Type: Grant
    Filed: November 9, 2000
    Date of Patent: September 6, 2005
    Assignee: Nortel Networks Limited
    Inventor: Michael A. Bobbitt