Detection of suspect software objects and signatures after failed authentication

摘要

In a system for authenticating a downloaded software object, a technique is provided to determine whether a failed authentication resulted from a suspect downloaded object or a suspect signature for the downloaded object which was communicated separately. A secret compact transformation function that operates on the signature is used to generate a value indicative of the signature at the software object transmission facility. The inverse function is used at the user terminal, such as a television set-top box, which receives the downloaded software object. Multiple transmission of the value can be provided for redundancy. The system is particularly useful in analyzing actual or attempted attacks on the security of the software object download scheme.