A publicly verifiable quantum blind signature scheme without entanglement based on asymmetric cryptography

In recent years, several cryptographic scholars have proposed quantum blind signature schemes. However, their methods require the signatories and the inspectors to share common keys in advance, which makes them not only complicated in concept, but also suffering deniable problem. Moreover, due to the fact that not everyone can verify the blind signature, it needs to have a designated verifier. In view of Laurent, et al.’s argument that other than the assumption of the pre-image being collision-free, the one-way hash function is an attractive cryptographic component in the post-quantum era when designing a cryptosystem. Inspired by this, we propose a publicly verifiable quantum blind signature scheme based on the hash function. After security analyses, we confirm that our quantum blind signature not only is secure, but also have the needed properties. It includes anonymity, unforgeability, non-repudiation, blindness, public verifiability, and traceability. Hence, we conclude that this approach is better than the state-of-the-art, and is therefore more suitable for applications in real life, such as, mobile payments, quantum voting, or quantum government

An Efficient Secure Anonymous Proxy Signature Scheme

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, several studies about proxy signature schemes have been conducted but only Yu et al.’ anonymous proxy signature scheme proposed in 2009 attempting to protect the proxy signer’s privacy from outsiders. They claimed their scheme can make the proxy signer anonymous. However, based on our research, we determined that this was not the case and the proxy signer’s privacy was not anonymous. Hence, in this paper, we propose a new anonymous proxy signature scheme that truly makes the proxy signer anonymous while making it more secure and efficient when compared with Yu et al.’s scheme in 2009. Our proxy signature scheme consists of two constructions. First, we mainly use random numbers and bilinear pairings to attain the anonymous property in our proxy. Secondly, we increase the security, integrity, and efficiency of our proxy through modifications

A publicly verifiable quantum signature scheme based on asymmetric quantum cryptography

In 2018, Shi et al. \u27s showed that Kaushik et al.\u27s quantum signature scheme is defective. It suffers from the forgery attack. They further proposed an improvement, trying to avoid the attack. However, after examining we found their improved quantum signature is deniable, because the verifier can impersonate the signer to sign a message. After that, when a dispute occurs, he can argue that the signature was not signed by him. It was from the signer. To overcome the drawback, in this paper, we raise an improvement to make it publicly verifiable and hence more suitable to be applied in real life. After cryptanalysis, we confirm that our improvement not only resist the forgery attack but also is undeniable