Regulatable and Hardware-Based Proof of Stake to Approach Nothing At Stake and Long Range Attacks

Abstract

Proof of Stake powered blockchains account for general trends in existing consensus mechanisms. However, existing PoS protocols are vulnerable to the nothing at stake and long range attacks, which allow attackers to gain unfair shares based on costless simulations and malicious sale information. In a decentralized setting, these securities are limited as each node is unregulated. To address these problems, we introduce a proof-of-hardware-stake (PohS) consensus mechanism and a regulatory mechanism based on a consortium blockchain. Our approach is implemented in a sharding blockchain to scale the consensus. Since any node on the network cannot fake information, the blockchain trustless won not be decreased by the reliance on a consortium blockchain. Under the competing rule of PohS consensus mechanism, adversaries can issue the long range attack with at most <inline-formula><tex-math notation="LaTeX">$10^{-3}$</tex-math></inline-formula> probability. The regulatory mechanism implements the regulation of costless simulations at the nothing stake attack. We prove that our design is secure (<i>e.g.,</i> 51&#x0025; and selfish mining) against adversarial stakes less than 51&#x0025; by adopting the square root of stakes for competition. Our proof also highlights the security of double-spending and long range attacks. Simulations are conducted to compare the efficiency of our approach with Ethereum and Ouroboros.