The Relevant Research On Signcryption

Now, the humanity enters the information society, the status and role of information in society is becoming increasingly important. Specially along with Internet rapid development, More and more people use the Internet to transmit information .the electronic commerce, the electronic government affairs are to flourish, and ensure the authenticity and integrity of information disseminated on the Internet, Realized the safe correspondence already urgent. Cryptography technology is the most important means of communication to achieve security, which is the most commonly used are encryption technology and digital signatures. Encryption technology can guarantee the confidentiality of information, makes any non-authorized persons can not know the contents of the news. Digital signatures can achieve and be able to identify the source, the receiver can determine who is the sender information.1997 Zheng proposed a novel cryptographic primitive which called signcryption. The main idea of signcryption is to encrypt and sign data in a single step. The new method is more efficient and has low computational cost and communication overhead compared with traditional signature-then-encryption way. Therefore, it is the more economical method for secure and authenticated transactions/message delivery. Signcryption schemes are compact and particularly suited for efficiency-critical applications such as secure ATM networks, secure and authenticated key establishment, secure multi-casting over the Internet, authenticated key recovery.The main research results in this paper includes:1. The scheme proposed by Zheng can provide both encryption and signature characteristics in a economical way. The original scheme may satisfy confidentiality, verifiability, but can not provide non-repudiation, forward security and public verifiability. Then we propose a new modified scheme on the basis of Zheng's original scheme, which can offer the public verifiability.2. Since 1997, many different signcryption schemes are proposed, such as blind signcryption, group signcryption, proxy signcryption and so on. In many cases, we need to prohibit a single recipient from recovering a signcrypted message. In this paper, an ID-based signcryption scheme with (t, n) shared unsigncryption is proposed, which is the integration of the KCDSA signcryption scheme and the Shamir's (t, n) threshold scheme. The new scheme provides public verifiability.3. Forward secrecy, it means that an attacker cannot read signcrypted messages, even with access to the sender's private key. That is, the confidentiality of signcrypted messages is protected, even if the sender's private key is compromised. In this paper, we proposed a new threshold unsigncryption scheme that can satisfy forward security.