Research Of Identity Based Threshold Secret Sharing And Its Applications

Secret sharing is one of the most important research fields of modern cryptography. With the rapid development of distributed system and pervasive computing, secret sharing is playing a more and more significant role in designing security schemes. IBE is a popular public key encryption scheme in information security fields. However, because of the dependence of centralized PKG, IBE algorithm has disadvantages of power centralization and single point of failure (SPoF), which restrict its implementation in distributed networks deeply. Although secret sharing can be considered as solutions for the problems mentioned above, there are challenges of the research field due to the complex of application environments. Reviewed from present literature, the research on ID based secret sharing is not ideal and there exist several open problems, such as verifiable, proactive and so on. In this thesis, we analysis the security requirement of distributed networks, combine the advantages of IBE and threshold secret sharing, design practical ID based secret sharing schemes. The advantage of the proposed schemes is the balance of security and availability. In the last, two schemes in particular environments are proposed. The contributions are summarized as follows:(1) Focus on the shares cheating attack during the secret sharing schemes, an ID based verifiable secret sharing scheme is proposed. The scheme based on a non-interactive zero knowledge proof protocol named B-DLEQ, the public proof of shares are generated based on the features of bilinear maps. The verify algorithm are deeply integrated with secret distribute algorithm, so that the verify information and the secret shares can be carried out simultaneously in order to save computation costs. Finally, the performance of the scheme is analyzed in detail.(2) The issues of rekeying in ID based secret sharing scheme are discussed. In order to protect long-lived and sensitive secrets, an ID based proactive secret sharing scheme is proposed. The scheme employed the one-way hash chain to renew secret shares, which saves the computation costs of generating random polynomial in traditional PSS. In addition, the security of secret distribution, shares transmission and renewing are analyzed as well as the performance of computation, storage costs and communication costs. At last, comparison analysis and simulation results demonstrate the improvement of the performance.(3) Consider the rational behaviors of participants in ID based secret sharing scheme and study the ID based rational secret sharing scheme with random rounds interactive. Since rational individuals prefer to get the secret than not to get it and prefer that as few of the other players get the secret, the traditional scheme doesn't work well. We address an ID based rational secret sharing scheme based on repeated game theory. In the scheme, shares are distributed by dealer encoded by a bilinear pairing in finite field. In reconstruction process, players exchange their shares in a finite repeated game. The mechanism of the scheme makes all players have incentive to cooperation. Finally, the security analysis and complexity analysis are addressed.(4) Study the application of ID based secret sharing in privacy protection of ubiquitous communication and broadcast encryption of hierarchical networks. Firstly, the traditional applications of secret sharing such as data signature and digital auction are discussed. Secondly, focuses on the secure challenges of the ubiquitous communication and hierarchical networks, proposes ID based secret sharing solutions respect. In ubiquitous communication environment, we apply different private policy according to different trust domains. In hierarchical networks'broadcast encryption, we employ ID based secret sharing to distribute symmetric session keys, so that both the security and availability can be achieved. In the end, the performance analyses of the proposed schemes are addressed.