Valuable Puzzles for Proofs-of-Work

Abstract

Proof-of-work (PoW) is used as the consensus mechanism in most cryptocurrencies. PoW-based puzzles play an important part in the operation and security of a cryptocurrency, but come at a considerable energy cost. One approach to the problem of energy wastage is to find ways to build PoW schemes from valuable computational problems. This work proposes calibration of public key cryptographic systems as a suitable source of PoW puzzles. We describe the properties needed to adapt public key cryptosystems as PoW functions suitable for decentralised cryptocurrencies and provide a candidate example.