Proxy signcryption scheme with public verifiability and controllable authority

Abstract

The Shin's signcryption scheme with public verifiability of Shin et al. and the proxy signcryption scheme of Jung et al. were cryptoanalyzed and improved. By studying the confidentiality of Shin's scheme and Jung's scheme, and the proxy authority of Jung's scheme, the fact is that the confidentiality of Shin's scheme and Jung's scheme was lost, and the proxy authority of Jung's scheme was not controlled. Then a modification based on Shin's scheme was presented. The modification was a security proxy signcryption scheme with public verifiability and controllable authority. Based on some cryptographic assumptions, the security of the scheme was also proved.