Patent ID: 7917746

Claim:
A method of verifying data protected by a digital certificate and transmitted in a digital transmission system, the method comprising: receiving, using a processor, said data protected by the digital certificate, a first issue date corresponding to a date on which said data was issued, and at least two encrypted values determined for at least one portion of said data, wherein the data is an update of previously transmitted data, and wherein each of the at least two encrypted values is determined using a key corresponding to an encryption algorithm; verifying, using the processor, that the first issue date is later than a second issue date corresponding to a date on which said previously transmitted data was issued; processing, using the processor, each of the at least two encrypted values using a stored public key corresponding to the encryption algorithm to obtain at least two resulting values; comparing, using the processor, each of the at least two resulting values with the at least one portion of said data to verify the at least one portion of said data; and rejecting the data when the at least two resulting values are different, wherein the digital certificate comprises the public key corresponding to the encryption algorithm.