Research On Broadcast Encrytion Schemes

With the development of technology and society, modern technology of communication also gained the rapid development. Usual computer communication is based on point to point operate mode, which differs from broadcast encryption that is based on one point to multiple points operate mode. So the efficiency of broadcast encryption, which is an important tools in the filed of information, is more high than usual communication method, which is a main point for the recently research for modern encryption theory on broadcast encryption. In 1993 Fiat firstly advanced the concept of broadcast encryption and showed the theory about it. Afterwards many scholars study on this filed and many good methods for broadcast encryption are proposed. And there are also some special broadcast encryption methods. Broadcast encryption is a new search field in the encryption and decryption field. Broadcast encryption could be used in the application of many fileds such as digital copyright, charged television, CD, DVD, media protection, file protection, secure email, etc.However, many broadcast encryption methods either have potential security hazard or have low efficiency.In this paper the author spend some time on the search of secure, efficient broadcast encryption schemes and gained some useful progress. The following are the main research:1. Research on broadcast encryption schemes based on polynomial interpolation. Through the compare of Shamir's scheme and Huang's HLC scheme, we pointed the difference of them and the advantage and disadvantange.2. Based on the property of polynomial interpolation and Chinese remainder theorem we construct a new broadcast encryption scheme which has small length of ciphertext and small space for users.3. We studied the VJPC scheme and found a big problem. So we proposed a new broadcast encryption scheme and modify this problem. The scheme has small ciphertext length and is secure under the DBDH assumption.