Analysis And Design Of Digital Signatures Based On Elliptic Curve Cryptography

With popularization and application of computer network, people more focus on information security. The goal of Information security is to provide information security, assured data integrity, realizes identity authentication and data availability.Data encryption and signature are the important techniques in information security. Elliptic Curve Cryptography (ECC) has shorter key size than other public-key cryptographies have in the same security level, which has a bright application prospect. This paper mainly analyses and designs the digital signatures based on ECC.According to factors considered in designing signature, this paper summarizes some designing rules, which provide some help to judge schemes rationality and security.Batch signature scheme has high efficiency in signature procedure. But signature and plain text must send to verifier at the same time when use hash functions, which make the messages not have confidentiality. Authenticated encryption scheme provide confidentiality when sign a message, but sign a single message in one time. We proposed a batch authenticated encryption scheme. This scheme provide confidential when batch sign messages, and realize public verifiability.Forward-secure digital signature is the scheme means when the secret key of current time period is compromised, it is not possible to forge the signatures relating to the past .This paper analyze the security of two forward-secure signatures, points out that the two schemes are not secure, both have the universal forgery. We design a forward-secure signature based on ECC. In scheme ,the signer private-key is hiding using multiplication by variable.It can avoided getting the const factor, and meet the forward-secure signature demand. In the research on threshold signature, this paper analyze the security of two threshold signatures, point out that two schemes suffer from conspiracy attack and are insecure. Adversary can forge a valid threshold signature by conspiracy. We Proposed a improvement scheme, which can withstand conspiracy attacks. Adversary can not forge a valid signature.