Identity-Based Signcryption from Identity-Based Cryptography

摘要

A signcryption scheme encrypts and signs data in a single operation which is more efficient than using an encryption scheme com bined with a signature scheme. Identity-based cryptography (IBC) does not require users to pre-compute key pairs and obtain certificates for their public keys. Identity-based signcryption (IBSC) applies the idea of IBC to signcryption. IBSC involves five security notions: message confidential ity, signature non-repudiation, ciphertext anonymity, ciphertext unlink ability, and ciphertext authentication. Recently, the Pandey scheme has been proposed; the scheme uses an identity-based encryption scheme and an identity-based signature scheme. However, this scheme only achieves message confidentiality and signature non-repudiation. In this work, we improve the scheme to achieve additional security notions, ciphertext anonymity and ciphertext authentication, with no loss in efficiency.