Patent ID: 7890763

Claim:
A method of identifying invalid digital signatures involving batch verification, comprising the steps of: a) receiving on an electrical computer a plurality of corresponding digital messages, digital signatures, and signer identifiers; b) computing on the electrical computer a value Z 0 as a function of the digital messages, the digital signatures, and the signer identifiers, where Z 0 is an element of a group, and where the group has an identity element; c) determining on the electrical computer if the digital signatures, as a batch, are valid for their corresponding digital messages and signer identifiers; d) if the digital signatures, as a batch, are valid then stopping, otherwise proceeding to step (e); e) assigning on the electrical computer a user-definable signature identifier to each digital signature; f) setting on the electrical computer w equal to 1; g) computing on the electrical computer Z w as a function of the digital messages, the digital signatures, the signer identifiers, and the signature identifiers; h) searching on the electrical computer for a multiplicative relationship amongst Z 0 , Z 1 , . . . , Z w ; and i) if a multiplicative relationship is found in step (h) then determining on the electrical computer the invalid digital signatures from the multiplicative relationship and stopping, otherwise incrementing w and returning to step (g) for additional processing.