Sahadeo Padhye

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Due to avoiding the key escrow problem in the identity-based cryptosystem, certificateless public key cryptosystem (CLPKC) has received a significant attention. As an important part of the CLPKC, the certificateless authenticated key agreement (CLAKA) protocol also received considerable attention. Most CLAKA protocols are built from bilinear mappings on(More)
Multi-proxy signature is one of the useful primitives of the proxy signature. Till now, only a few schemes of identity-based multi-proxy signature (IBMPS) have been proposed using bilinear pairings, but most of the schemes are insecure or lack a formal security proof. Because of the important application of IBMPS scheme in distributed systems, grid(More)
In this paper we analyze the security of Koyama scheme based on the singular cubic curve for some well known attacks. We provide an efficient algorithm for linearly related plaintext attack and identify isomorphic attack on Koyama scheme. Some other attacks are also discussed in this paper.
Proxy signature is a specific digital signature, which allows an original signer to delegate her signing capability to proxy signer and then, the later can perform message signing on behalf of the former. Authentication is a desired property in cryptographic protocols. The proxy signature provides this property. In this article, we cover the research(More)