Private Key Distribution Scheme Of IBE System

With the development of electronic business and electronic government, people must confront the risk of information security when they are enjoying the advantage brought with information industry. Cryptography is the basis technology which can protect information security. If you want to achieve information protection or user's status authentication, PKI (Public Key Infrastructure) is popular. Because PKI may make people believe in each other, provide the following four security requirements of confidentiality, authenticity, integrality and non-repudiation for information transmitted in the network, so PKI is using in more and more different fields. Of course, PKI is not perfect , it also has many limitations, for example, a PKI system will cost too much, its using is complicated , problems are still exist in the process of Certificate management and Certificate Revocation, if a user doesn't have his certificate ,he can't be communicated securely ,and so on. We need a new scheme to solve above problems. The identity-based system was proposed in such demand. Because it doesn't need certificates, identity could use as his public key directly ,it is think as the best way to predigest public key cryptography.Identity-based cryptograph has two different directions, one is on the basis of linear mapping, it is also to say by the weil pairing , the other depends on the intractability of the discrete logarithm and the large integer factoring problem . For the moment, most research focus on the linear mapping. After Boneh D and Franklin M proposed a perfect and practical identity-based encryption system, identity-based system based on linear mapping is becaming more and more perfect ,many correlative schemes were put forward , such as the signature algorithm in Identity-based Cryptography, Hierarchical ID-based Cryptography, Tripartite Authenticated Key Agreement Protocols, ID-based (t, n )threshold cryptographic key distribution scheme.The Identity-based encryption depends on linear mapping goes through two stages: in the first stage, the Private Key Generator transmits user's private key to him directly, the user uses the key as his communication private key. In the second stage, the idea of Diffie-Helllman was introduced to the primary system, which can make user's status authentication come true. But, both these two stages couldn't solve the nature of key escrow problem in the identity–based encryption system.In this paper, we present the existing Identity-base encryption, on the basis of this ,we also combine the development of Identity-based encryption depend on weil pairing , then introduce (t , n ) threshold scheme and improved RSA algorithm, in the end , we propose a new key distribution scheme in the Identity-based cryptosystem. The advantage of our new scheme is that it can solve the problem of key escrow.