In this modern age of electronic era, digital signature scheme is a latest and burning platform for researcher. A variety of digital signature schemes are available in the literature of cryptography. Different signature schemes are used according to the peculiar requirement/situations. A plenty of digital signature schemes have been proposed and discussed. This paper presents a directed signatu...

In a proxy signature scheme, a potential signer delegates his signing power to a proxy, who signs a message on behalf of the original signer. In a blind signature scheme, the signee cannot link the relationship between the blind message and the signature of the chosen message. That is, the signee cannot make a linkage between the blind signature and the identity of the requester. Therefore, it ...

At the fourth ACM conference on electronic commerce (EC’03), S. Han, K.Y. Yeung and J. Wang proposed an ID-based confirmer signature scheme using pairings (actually, this is an ID-based undeniable signature scheme). However, in this paper, we will show that this signature scheme is not secure. The signer can deny any signature, even this signature is his valid signature and any one can forge a ...

This paper introduces the important concept of signature revocation. An important property of digital signature is nonrepudiatability that a signer can’t deny his legal signature. However, in some occasion a signer wants to take back his previously singed signature in a proper legal way, so that after certain interaction a signature can be regarded as invalidate. We originate a new study of ins...

This paper introduces a new concept called controllable ring signature which is ring signature with additional properties as follow. (1) Anonymous identification: by an anonymous identification protocol, the real signer can anonymously prove his authorship of the ring signature to the verifier. And this proof is non-transferable. (2) Linkable signature: the real signer can generate an anonymous...

Signature authentication is the most widely used method of verifying a person’s identity. The texture and topological features are the static features of a signature image. Baseline slant angle, aspect ratio, normalized area, center of gravity of the whole signature image and the slope of the line joining the center of gravities of two halves of a signature image are used as the texture and top...

Signature is mostly used as a means of personal verification focused the need for an automatic verification system. Verification can be categorized either Offline or Online it depends on the application which is used. Online systems uses information which are dynamic in nature information are captured at the time the signature is performed. Offline systems work on the scanned image of a signatu...