Proxy blind signature, which combines the properties of both proxy signature and blind signature, is useful in e-cash and e-commerce. In this paper, we present a verifiable self-certified public key scheme and a proxy blind signature scheme using the verifiable self-certified public key. The self-certified public key has an advantage which can withstand public key substitution attacks. As far a...

Proxy signature is an important cryptographic primitive and has been suggested in numerous applications. In this paper, we present an attack on the aggregate-signaturebased proxy signature schemes, then point out there are two flaws in BPW notion of security for proxy signature. Furthermore, we give arguments for partial delegation with warrant proxy signature schemes. We construct a new proxy ...

Abstract. With the help of a blind signature scheme, a requester can obtain a signature on a message from a signer such that the signer knows nothing about the content of the messages and is unable to link the resulting message-signature pair; namely, a blind signature scheme can achieve both blindness and untraceability. Due to the above properties, the blind signature scheme can be used in cr...

Blindness and unforgeability are two essential security requirements of a secure blind signature scheme. Blindness means that after interacting with various users, the signer can never be able to link a valid message pair. Blindness is meaningless if after interacting with various users, the signer is able to link a valid message signature pair. This security vulnerability is known as linkabili...

A proxy signature scheme allows a proxy signer to sign messages on behalf of an original signer. Proxy signature schemes have found numerous practical applications such as grid computing, mobile agent systems and cloud applications. Recently, Jiang et al. proposed the first lattice-based proxy signature scheme and claimed that their scheme provides all the security properties of a secure proxy ...

Proxy signature schemes can be used in many business applications such as when the original signer is not present to sign important documents. Any proxy signature scheme has to meet the identifiability, undeniability, verifiability and unforgeability security requirements. In some conditions, it may be necessary to protect the proxy signer’s privacy from outsiders or third parties. Recently, se...

Restrictive partially blind signature (RPBS) plays an important role in designing secure electronic cash system. Very recently, Wang, Tang and Li proposed a new ID-based restrictive partially blind signature (ID-RPBS) and gave the security proof. In this paper, we present a cryptanalysis of the scheme and show that the signature scheme does not satisfy the property of unforgeability as claimed....

We introduce the notion of automorphic signatures, which satisfy the following properties: the verification keys lie in the message space, messages and signatures consist of elements of a bilinear group, and verification is done by evaluating a set of pairing-product equations. These signatures make a perfect counterpart to the powerful proof system by Groth and Sahai (Eurocrypt 2008). We provi...

Delegation of signing rights is a central problem in security. Whereas delegating by givingpower of attorney is well studied and digitally realized via delegatable anonymous credentials,directly delegating signing possibilities without the need for an external logic, can be done viamalleable signature schemes. However, the existing schemes do not allow for privacy preserving,fin...

We propose a non-divisible electronic cash system that combines the restrictive blind signature technique and a batch signature scheme based upon the binary tree structure. Contemporary electronic cash solutions rely on the divisibility paradigm to achieve significant computational savings, and such techniques are considered to be the most efficient. We demonstrate an alternative approach that ...