Research On ID-Based Signature

Information technology is changing the world in a revolutionary way, meanwhile the importance of information security is emerging. As one of the core tech of information security, digital signatures play an important part in military affairs, telecommunication and e-commerce. ID-based cryptosystems avoid the complexity and cost of certificates authority in traditional public key cryptosystem. ID-based cryptosystems built on bilinear pairings are on the center of the stage. ID-based signatures boast their short length, however, the computing of pairing is very slow, which hinders the application of ID-based schemes.The work of this dissertation is mainly on ID-based signature, especially ID-based aggregate signature and ID-based blind signature. Given n signatures on n distinct messages from n distinct users, aggregate signature makes it possible to aggregate all these signatures into a single short signature. Aggregate signatures are useful for reducing the size of certificate chains (by aggregating all signatures in the chain), reducing message size in secure routing protocols such as SBGP and compressing signatures. Blind signature is a protocol involving two entities: user and signer. Blind signature allows a user to ask a signer to sign a message for him/her without letting the signer know anything about the message and the signature. This trait makes blind signature widely welcomed in e-cash schemes.The major results of my research are as follow: analyzing ID-Based signatures with a general model, comparing the efficiency and security of these schemes, analyzing and modifying an ID-base aggregate signature, updating the research achievements in ID-based blind signature, explaining the model of ID-based blind signature, analyzing the blinding procedure of ID-based signature with a general model and fixing some mistake in this model, and last but not least, proposing a ID-based blind signature, comparing the efficiency and security of existing ID-based blind signatures.