Research of Several Problems of Digital Signature and Authenticated Encryption
|School||Xi'an University of Electronic Science and Technology|
|Keywords||Digital Signature Authenticated encryption Secret Sharing Digital signcryption Discrete logarithm|
This dissertation mainly discusses the technique of digital signature and authenticated encryption (digital signcryption). The main results obtained are as follows: (1)A new multisignature scheme for specified group of verifiers is proposed; (2) A new signature scheme with threshold shred verification is proposed. Based on the proposed scheme, a new password shared authentication scheme is presented to repair the security flaw in Qi et al’s scheme;(3) We point out some weaknesses of two directed signature scheme proposed by Lim et al. and Qi et al. we proposed a directed signature scheme and a message recovery directed signature scheme based on discrete logarithm;(4) We point out that Shao’s signature scheme using self-certified public key is not efficient and the security proof of Shao’s scheme is not correct. We present a new signature scheme using self-certified public key;(5) We point out that Tseng et al.’s authenticated encryption scheme with message linkage does not satisfy non-repudiation and forward secrecy. We present a new authenticated encryption scheme with message linkage to overcome the weakness of Tseng et al.’s scheme;(6) We point out some weaknesses of the previously proposed proxy signcryption scheme. We present a public verifiable proxy signcryption scheme.