# Multi-Party Semi-Quantum Simultaneous Ascending Auction Protocol Based on Single-Particle States

## TL;DR

This paper introduces a semi-quantum auction protocol that allows multiple parties to bid on items simultaneously using simple quantum resources.

## Contribution

The protocol enables multi-item simultaneous ascending auctions with minimal quantum capabilities and ensures security through a trusted third party.

## Key findings

- The protocol supports multi-item simultaneous ascending auctions using single-particle quantum states.
- Quantum circuit simulations confirm the protocol's feasibility and security with current technology.
- The solution satisfies anonymity, verifiability, non-repudiation, and privacy preservation.

## Abstract

Simultaneous ascending auctions find extensive applications in spectrum licensing and advertising space allocation. However, existing quantum sealed-bid auction protocols suffer from dual limitations: they cannot support multi-item simultaneous bidding scenarios, and their reliance on complex quantum resources along with requiring full quantum operational capabilities from bidders fails to accommodate practical constraints of quantum resource-limited users. To address these challenges, this paper proposes a multi-party semi-quantum simultaneous ascending auction protocol based on single-particle states. The protocol employs a trusted honest third party (HTP) responsible for quantum state generation, distribution, and security verification. Bidders determine their groups through quantum measurements and privately encode their bid vectors. Upon successful HTP authentication, each bidder obtains a unique identity code. During the bidding phase, HTP dynamically updates quantum sequences, allowing bidders to submit bids for multiple items by performing only simple unitary operations. HTP announces the highest bid for each item in real time and iteratively generates auction sequences until no new highest bid emerges, thereby achieving simultaneous ascending auctions for multiple items. It acts as a quantum-secured signaling layer, ensuring unconditional security for bid transmission and identity verification while maintaining classical auction logic. Quantum circuit simulations validate the protocol’s feasibility with current technology while satisfying critical security requirements, including anonymity, verifiability, non-repudiation, and privacy preservation. It provides a scalable semi-quantum auction solution for resource-constrained scenarios.