Generalized ID-based elgamal signatures and extensions
Author(s)
Advisor
Selçuk, Ali AydınDate
2008Publisher
Bilkent University
Language
English
Type
ThesisItem Usage Stats
170
views
views
57
downloads
downloads
Abstract
ID-based cryptography helps us to simplify key management process in traditional
public key infrastructures. Any public information such as the e-mail
address, name, etc., can be used as a public key and this solves the problem
of obtaining the public key of a party and checking that its certificate is valid.
ID-based cryptography has been a very active area of research in cryptography
since bilinear pairings were introduced as a cryptographic tool. There have been
many proposals for ID-based signatures recently. In this thesis, we introduce the
concept of generalized ID-based ElGamal signatures and show that most of the
proposed ID-based signature schemes in the literature are special instances of this
generalized scheme. We also investigate ID-based signatures providing additional
properties. Signature schemes with message recovery provide the feature that the
message is recoverable from the signature and hence does not need to be transmitted
separately. Blind signatures provide the feature that a user is able to get
a signature without giving the actual message to the signer. Finally, signcryption
schemes fulfill the job of a digital signature and encryption in a single step with
a lower computational cost.
We generalize the ID-based signatures providing these properties and obtain
numerous new signatures which have not been explored before. The generalized
ID-based signatures we described provide a unified framework for ID-based ElGamal
signatures and extensions. Additionally, some of our blind signatures turn
out to be more efficient than the previously proposed schemes.