Classification Digital signature schemes with appendix require the original message as input to the verification algorithm Digital signature schemes with message recovery do not require the original message as input to the verification algorithm. In this case, the original message is recovered fro om the signature itself.4 Classification • Digital signature schemes with appendix require the original message as input to the verification algorithm. • Digital signature schemes with message recovery do not require the original message as input to the verification algorithm. In this case, the original message is recovered from the signature itself