Surveying Quantum-Proof Blockchain Security: The Era of Exotic Signatures

Abstract

Blockchain technology has emerged as a cornerstone of se- cure online activities, leveraging an extensive array of cryp- tographic tools. This paper delves into an extensive survey of the current literature on post-quantum secure digital sig- natures, focusing on those with advanced, exotic features that play pivotal roles in the blockchain ecosystem. These signatures serve essential functions, including account man- agement,enhancing consensus efficiency,enabling scriptless blockchains, and fortifying user privacy. The term "exotic" in this context signifies signatures that transcend conven- tional properties such as unforgeability, introducing novel functionalities that redefine the blockchain landscape. Our exploration centers on several such exotic signatures, in- cluding multi-/aggregate, threshold, adaptor, blind, and ring signatures. These cryptographic innovations not only bolster security but also empower blockchain systems in unprece- dented ways.Within this comprehensive treatment of exotic signatures, we engage in discussions surrounding the pre- vailing challenges and chart promising avenues for future research within the post-quantum realm. As quantum threats loom ever closer, our aim is to catalyze further inquiry, facil- itating the broader accessibility of post-quantum cryptogra- phy. This, in turn, will fortify blockchain systems, preparing them to withstand the impending quantum era while fos- tering innovation and excellence in the field of blockchain security.