In this paper, we survey all related threshold signature schemes and classify them with different properties. In order to compare them with different properties, we image there is an ideal threshold signature scheme which satisfies all requirements of threshold signature schemes. Based on this ideal threshold signature, readers can easily to understand what the next generation of threshold sign...

This article presents an efficient divisible blind signature scheme that makes it possible to divide a blind signature with a specified value into a sequence of subsignatures with smaller values for a sequence of different designated verifications. In the proposed scheme every signature can be divided into subsignatures with arbitrary positive values as long as the total value of them is equal ...

We present a method for blind certifying end-users' public keys and its application in offline electronic cash. A blind certificate of a public key is similar to an ordinary public-key certificate, however the identity of the certificate holder is concealed under the key certified. A digital signature supported by a blind certificate can be verified without identifying the signer. The technique...

A proxy blind signature scheme is combination of two signature schemes particularly proxy signature and blind signature. In this signature scheme the original signer delegate his/her signing authority to some other entity named proxy signer. The proxy signer signs the documents or messages, but he cannot be able to find any link between the blind signature and the identity of the signature requ...

Here we present a stamped blind digital signature scheme which is based on elliptic curve discrete logarithm problem and collision-resistant cryptographic hash functions.

We introduce a new concept called convertible undeniable signature schemes. In these schemes, release of a single bit string by the signer turns all of his signatures, which were originally undeniable signatures, into ordinary digital signatures. We prove that the existence of such schemes is implied by the existence of digital signature schemes. Then, looking at the problem more practically, w...

In this study, the security of Novel Enhanced Quantum Representation (NEQR) of quantum images are suggested by using the Quantum Fourier Transform (QFT ) with blind trent. In the protocol, QFT and keys are used to share signature with recipients. So all members know only their signature information which are encrypted output of the QFT . This improves the security of the protocol. In addition, ...

The paper proposes a general method for construction cryp-toschemes based on difficulty of simultaneous solving factoring (FP) and discrete logarithm modulo prime problem (DLpP). The proposed approach is applicable for construction digital signatures (usual, blind, collective), public key encryption algorithms, public key distribution protocols, and cryptoschemes of other types. Moreover, the p...

To enhance the efficiency of threshold group signature schemes, Yu and Chen, recently, proposed an efficient threshold group signature scheme. By using elliptic curves, the proposed scheme can use short secret key and reduces the load of signature verification. However, in this paper we find that there are many ambiguities in the proposed scheme. The verifiers cannot verify valid signatures, wh...

Based on the anonymity that digital signatures provide to users and messages, digital signatures can be classified as hidden, weak, interactive, or strong blind signatures. The hidden blind signature hides the signed message from the signer’s vision during his interaction with an honest requester. Later on, after revealing the message the signer can easily link the message-signature pair. The h...