Towards Quantum-Secured Permissioned Blockchain: Signature, Consensus, and Logic

• Main Authors: Xin Sun, Mirek Sopek, Quanlong Wang, Piotr Kulicki
• Format: Article
• Language: English
• Published: MDPI AG 2019-09-01
• Series: Entropy
• Subjects: blockchain; quantum computing; consensus; digital signature; lottery
• Online Access: https://www.mdpi.com/1099-4300/21/9/887

While Blockchain technology is universally considered as a significant technology for the near future, some of its pillars are under a threat of another thriving technology, Quantum Computing. In this paper, we propose important safeguard measures against this threat by developing a framework of a quantum-secured, permissioned blockchain called Logicontract (LC). LC adopts a digital signature scheme based on Quantum Key Distribution (QKD) mechanisms and a vote-based consensus algorithm to achieve consensus on the blockchain. The main contribution of this paper is in the development of: (1) unconditionally secure signature scheme for LC which makes it immune to the attack of quantum computers; (2) scalable consensus protocol used by LC; (3) logic-based scripting language for the creation of smart contracts on LC; (4) quantum-resistant lottery protocol which illustrates the power and usage of LC.