A method and apparatus for verifying revocation status of a digital certificate is provided. The invention operates in part by a receiver verifying a security certificate for a sender. In various embodiments the steps to accomplish this include receiving a first security certificate associated with the...http://www.google.co.uk/patents/US7500100?utm_source=gb-gplus-sharePatent US7500100 - Method and apparatus for verifying revocation status of a digital certificate
