Abstract: Self-certified cryptosystem realizes the properties of no public key certificate and key-unescrow, proxy signcryption is a scheme that combines the proxy signature and signcryption. By merging the thoughts of self-certified cryptosystem and proxy signcryption, a new self-certified proxy signcryption scheme based on discrete logarithm problem was proposed on the basis of the existing literatures. Under the hardness of discrete logarithm problem in finite field, the new scheme was proved to be correct and secure.

Key words: Discrete logarithms problem in finite field, Proxy signcryption, Pubfic verifiability, Self-certified cryptosystem