Blind signature (BS) plays one of key ingredients in electronic cash or electronic voting system. However, the key exposures bring out very serious problems in insecure mobile devices. Forward-secure blind signatures preserve the validity of past signatures and prevent a forger from forging past signatures even if current secret key has been compromised. In this paper, we propose the first forw...

Restrictive partially blind signatures incorporate the advantages of restrictive blind signatures and partially blind signatures, which play an important role in electronic commerce. Recently, Chen-Zhang-Liu first proposed an ID-based restrictive partially blind (IRPB) signature from bilinear pairings. Later, Hu-Huang showed that the Chen-Zhang-Liu’s scheme has a security weakness, and pointed ...

Delegation of rights is a common practice in the real world. We present two identitybased threshold proxy signature schemes, which allow an original signer to delegate her signing capability to a group of n proxy signers, and it requires a consensus of t or more proxy signers in order to generate a valid signature. In addition to identity-based scheme, privacy protection for proxy singers and s...

Blind signatures are well-studied building blocks of cryptography, originally designed to enable anonymity in electronic voting and digital banking. Identity-based signature were introduced by Shamir 1984 gave an alternative prominent Public Key Infrastructure. An identity-based blind ( $$\textsf{IDBS}$$ ) allows any user interact directly with the signer without prior interaction a trusted aut...

signature s hemes based on the Gap-DiÆe-Hellman-group signature s heme Alexandra Boldyreva August 12, 2002 Abstra t We propose a robust proa tive threshold signature s heme, a multisignature s heme and a blind signature s heme whi h work in any Gap DiÆe-Hellman (GDH) group (where the Computational DiÆe-Hellman problem is hard but the De isional DiÆe-Hellman problem is easy). Our onstru tions ar...

In a nominative proxy signature scheme, an original singer delegates his signing power to a proxy signer, who generates a nominative signature on behalf of the original signer. In a nominative proxy signature scheme, only the nominee can verify the signature and if necessary, only the nominee can prove its validity to the third party. In this paper, we first classify the nominative proxy signat...

In the past few years, many excellent studies on proxy signature schemes have been published. Yet, traditional proxy signature schemes are mainly aimed at dealing with one or two separate proxy conditions each. In this article, the authors shall present a generalized version of the (t1/n1 – t2/n2) proxy signature scheme based on the discrete logarithms that can be applied to every proxy situati...

In a nominative proxy signature scheme, an original singer delegates his signing power to a proxy, who generates a nominative signature on behalf of the original signer. In a nominative proxy signature scheme, only the nominee can verify the signature and if necessary, only the nominee can prove its validity to the third party. In this paper, we first classify the nominative proxy signature int...