Security protocols usually rely on the cornerstone applications of digital signatures for authentication, integrity, and non-repudiation. For instance, code signing of devices for legitimate software updates, Distributed Ledger Technology to ensure valid cryptocurrency transactions, and Vehicular Ad hoc NETwork to ensure reliable message communication among vehicles or road-side units uses digital signatures.

In these real-world scenarios, the most widely used cryptographic schemes for digital signatures are RSA, DSA, and ECDSA. The security of these classical cryptographic primitives relies on the hardness of factoring integers and computing discrete logarithms. The current algorithms use large-sized cryptographic primitives that make it infeasible (and expensive) to solve discrete logarithm problem. This situation is currently valid for traditional computing systems. However, with the not-so-far arrival of quantum computers, these computational problems will be susceptible to quantum computer cryptanalysis using Shor’s algorithm. Furthermore, Grover’s algorithm can allow brute-force attacks to address quantum computing’s effect on symmetric cryptography. Therefore, the reliance on de-facto cryptographic primitives’ security is at risk of being broken by the impending quantum computers.

With the proliferation of quantum computing technologies, the epoch-making incident of the end of the currently used classical digital signature scheme in the foreseeable future raises the following concerning questions