An investigation and design of post quantum privacy preserving signatures

Abstract

Digital signatures play an extremely important role in software updates, online payments, e-banking, e-commerce, etc. It is considered to be the most important tool to provide authentication of a message and achieve information security. In the current era, most of the digital transactions use digital signatures that are publicly verifiable and they bind the signatory to the message. The privacy of signatures is a very sensitive and generic concept due to which different types of signatures have been evolved. Based on various situations and scenarios, many schemes have been proposed in the literature. In general, privacy providing signatures can be classified on the basis that they protect signers identity from being revealed to unauthorized parties which are not associated with it, or they make the signed message to pre-designated parties private. Various types of non-transferable signatures are available and some of them are undeniable signatures, designated verifier signatures, chameleon signatures, nominative signatures, universally designated verifier signatures, etc. The majority non-transferrable signatures are constructed based on the hardness of discrete logarithm problem and integer factorization problem. However, these problems could be solved in polynomial time by quantum computer (Shor 1994). Hence, it is of utmost importance to develop non-transferable signatures which remain secure even when the adversary has access to a quantum computer. In an attempt to address this problem, this research proposes non-transferable signature schemes that are secure and safe to quantum attacks Hash-based signature schemes are considered as an efficient replacement to those schemes that are vulnerable to quantum computer attacks. One of the primary advantages in the construction of this scheme is that it does not require any specific complex algebraic structures and mathematical operations, but has very minimal requirements such as the existence of cryptographic hash functions. These functions ensure the integrity