Researching Of Key-insulated Signature Cryptosystem And Application

Nowadays,many people graft their business into the intelligent terminal, and along with more and more business grafted on, more and more sensitive data are recorded in the intelligent terminal. Data leakage becomes a part of economic loss which cannot be ignored. Among all the issues in data leakage, key leakage is the most serious threat. Current cryptosystems are all based on the key confidentiality, so if the key was leaked, the cryptosystems and users will be threatened. In order to reduce the loss of key leakage, many scholars have provided a lot of ideas or schemes. Key-insulated is one of those researches. Because of the importance of key insulated schemes against key compromise, in this thesis, the key-insulated signature scheme and its applications were studied. The main contributions of this thesis are:1. This thesis reviews those researches of key-insulated signature schemes. It describes the basic concepts of key-insulated signature scheme, the formal definition, security model, security characteristic, and commonly mathematic tools. The classical key-insulated signature scheme and the design principles of the key-insulated scheme were analyzed in-depth.2. After studying the key-insulated signature, this thesis proposes an identity-based parallel key-insulated signature scheme based on an efficient signature scheme. This scheme not only has the ability of the key insulated but also has secure key updates, unlimited time etc. This scheme is more efficient than other similar scheme, and it reflected to the simulation test which is based on JPBC.3. The current existing key-insulated ring signature scheme has a huge of computing consumption. This thesis presents an efficient identity-based key-insulated ring signature scheme. This scheme is more efficient than other schemes in verification process, and there is no security cut back.4. Based on a proxy signature scheme with authorization, this thesis proposed a proxy identity-based key-insulated signature scheme. In addition to the setup process of this scheme, other processes, such as consultation proxy signature key, don’t need to communicate with PKG. The design of this scheme also took the circumstances of those keys of original signer, proxy signer and proxy signature were leaked into account, so this scheme made the corresponding safeguard. This scheme is safe and efficiency.5. There doesn’t have a key-insulated proxy blind signature scheme until now. This thesis proposes the first key-insulated proxy blind signature scheme. This scheme has features of blind signature and proxy signature: proxy signer can sign a message without knowing the message, and even this signature was published, the proxy signer also don’t know the sign time.