MODIFIED ELLIPTIC CURVE SIGNATURE ALGORITHM FOR MESSAGE RECOVERY

摘要

A modified Chinese State Encryption Management Bureau's SM2 Elliptic Curve Signature Algorithm that offers partial message recovery and lowers the signature size for a given cryptographic strength. The modified SM2 Elliptic Curve Signature Algorithm includes a signature and verification algorithm that modifies a signature generation primitive to compute a key derived from the ephemeral signing key, and a multiple of the signer's public key.

主权项

1. A digital signature generation method for a transmitting-entity, comprising:
partitioning a message to be transmitted into a first portion and a second portion; generating an ephemeral key; calculating an encryption key based on the generated ephemeral key and a public key; computing a ciphertext by encrypting the first portion of the message using the calculated encryption key; computing a hash value by applying a first hash function to a concatenation of an identity hash value, the computed ciphertext, and the second portion of the message; calculating a signature key using a private key, the calculated encryption key, and the computed hash value; and outputting an enciphered message that includes the calculated signature key, the computed ciphertext, and the second portion of the message.