The present e-payment schemes permit anonymity property to protect customer privacy. However, the majority of these schemes have not offered a non-denial property. For example, several difficulties subsist in the schemes such as repudiation, loss, abuse, theft, and overspend-tracing. This article suggests an e-payment scheme wherein a temporary anonymous public key is embedded in a partial blin...

Reducing the risk of information leaks is one of the most important functions of identity management systems. To achieve this purpose, Dey et al. have already proposed an account management method for a federated login system using a blind signature scheme. In order to ensure account anonymity for the authentication provider, referred to as an IDP (identity provider), a blind signature scheme i...

Received Dec 10, 2016 Revised Apr 25, 2017 Accepted Jun 11, 2017 Blind signature allows a user to obtain a signature on a message without revealing anything about the message to the signer. Blind signatures play an important role in many real world applications such as e-voting, e-cash system where anonymity is of great concern. Due to the rapid growth in popularity of both wireless communicati...

In the universal composability framework, we define an ideal functionality for blind signatures, as an alternative to a functionality recently proposed by Fischlin. Fischlin proves that his functionality cannot be realized in the plain model, but this result does not apply to our functionality. We show that our functionality is realized in the plain model by a blind signature protocol if and on...

Key exposure problem turns out to be very serious in security services. For example, in electronic cash, the problem is very severe since money is directly involved. In other applications of cryptography, it is also a devastating attack. Forward security is the first security notion addressing the this issue. Roughly speaking, forward secrecy is aimed to protect validity of the all usage before...

Key exposures bring out very serious problems in security services. Especially, it is more severe in the applications such as electronic cash or electronic payment where money is directly involved. Forward secrecy is one of the security notions addressing the key exposure issues. Roughly speaking, forward secrecy is aimed to protect the validity of all actions using the secret key before the ke...

A new blind signature protocol based on Schnorr signatures is presented that can be used in payment systems. Apart from its simplicity and efficiency, an important feature of the protocol is that it can be argued to imply a withdrawal protocol that is resistant to parallel attacks by a collusion of users. An essential property of the blind signature protocol is that the signer has complete know...

A low-computation partially blind signature scheme was proposed in 1998. Compared to the existing blind signature protocols, the scheme largely reduces the computation costs for each user by about 99%. However, a weakness on partial blindness is found in the scheme. This paper presents a new partially blind signature protocol with extremely low computation for each user. Not only is the propose...

Chen, Qiu, and Zheng proposed a Rabin-like blind signature scheme, which is based on the square-root problem. Although their scheme is simple and efficient, it can be compromised when choosing some particular blinding factors. In this manuscript, the scheme is demonstrated as not being secure.

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