Improved Convertible Signcryption Schemes
可转换签密的几种改进方案

Several convertible signcryption schemes with semantic security based on elliptic curve cryptosystem were proposed. In these schemes, if the signer denies her signcryption, the receiver could prove the dishonesty of the sender to any third party by converting the signcryption into an ordinary signature. These schemes have improved the weaknesses that the semantic security of the message couldn't be provided in H-C scheme (Huang WTBX]et al.WTBZ]'s scheme) and W-B scheme (Wang WTBX]et al.WTBZ]'s scheme) and the session key was easily divulged in H-C scheme. Compared with current schemes, our schemes have lower communication cost and computational cost.