A novel lottery protocol based on quantum blockchain

Abstract

The lottery business is a form of gambling activity operated by authority agencies. Due to the substantial economic interests, its security and fairness become the core elements of industry development. To maintain the trust of participants and ensure fair competition, blockchain technology has been widely applied in the lottery field due to the characteristics of decentralization, transparency, and immutability. However, with the rapid advancement of quantum computing, the security of traditional blockchain technology is challenged largely. To tackle this issue, a novel consensus mechanism which can resist quantum attacks is first proposed, based on a self-tallying quantum voting protocol. Then, a quantum circuit is designed, which can encode n-bit binary information into the relative phase of a quantum state and entangle the blocks by means of controlled-Z (CZ) gate, forming a quantum blockchain structure with timestamps. Finally, utilizing the designed quantum blockchain, a new type of lottery protocol is constructed. The proposed protocol meets the requirements of decentralization, unforgeability, verifiability, and quantum attack resistance. Compared to existing lottery protocols, it can support an arbitrary number of players, and only one communication is required for the ticket purchase process of each player, making it suitable for most of lottery game scenarios.