The invention discloses a Hash calculation method and a
signcryption method based on a homomorphic chameleon
Hash function. According to the provided homomorphic chameleon
hash function, a chameleon hash value result adopts a logarithm form, a
signcryption result based on the hash in the
signcryption method is also a logarithm form, so that the homomorphic property is achieved, the homomorphic aggregation can be conducted in hash calculation, hash is more efficiently calculated, and the homomorphic chameleon
hash function has both the homomorphic state and the
key leakage prevention characteristics. The signcryption method is realized on the basis of the homomorphic chameleon
hash function, the homomorphic aggregation signcryption ensures the homomorphism, the
system public parameters generated by the
system initialization are used together by the chameleon hash function and the signcryption, and two
password schemes share one set of
system parameters, so that
multiple function effectscan be realized under one set of shared
system parameters, and multiple functions are supported under the same framework. Secondly, the proxy
key generation and proxy re-signature steps realize the proxy re-signature, and the non-repudiation is realized through a repudiation step.