摘要:
A document is digitally signed with a digital signature that is unique to the signer/document pair. A document digest is generated by applying a predefined one-way hash function to the document. A pseudo-random key is generated by combining the document digest with at least one other value in accordance with a predefined computational procedure. The digital signature is then generated as a predefined function of the private key, the document digest, and the pseudo-random key k. A distinct pseudo-random key is generated for each distinct specified document, and for a given value of the private key, a distinct digital signature is generated for each distinct specified document. In a preferred embodiment the pseudo-random key generating step includes combining the document digest with a value corresponding to the private key to generate an intermediate value, and hashing the intermediate value with the predefined one-way hash function to generate the pseudo-random key k. In another preferred embodiment the pseudo-random key generating step includes hashing the private key with the predefined one-way hash function to generate a first intermediate value, combining the document digest with a value corresponding to the first intermediate value and an ancillary secret value to generate a second intermediate value, and hashing the second intermediate value with the predefined one-way hash function to generate the pseudo-random key k.