Aggregating subjective preferences in social choice traditionally assumes a trusted central authority. In contrast, this paper formalises Decentralised Preference Discovery (DPD): the reliable identification of a social choice parameter (e.g. the canonical outcome of an aggregation rule applied to the global preference profile) under conditions of partial information, asynchronous interaction, censorship resistance, and no central coordinator. To address DPD, we propose Snowveil, a gossip-based framework where agents repeatedly sample random peer rankings and update local beliefs to converge on the canonical outcome. Using a potential function, submartingale theory, and concentration bounds, we prove the system reaches this stable state with tunable high probability, in finite expected time. This single-winner process can then be iterated to construct a set of winning candidates for multi-winner scenarios. Snowveil is agnostic to specific aggregation rules, requiring only that the rule satisfies axioms such as Positive Responsiveness, thus offering a formal basis for a wider class of DPD protocols. Demonstrating Snowveil's modularity, we introduce the Constrained Hybrid Borda (CHB), an aggregation rule designed to balance broad consensus with plurality support. We provide an axiomatic analysis of CHB and present empirical results via extensive simulation, validating Snowveil's O(n) scalability. Overall, this work provides a foundation for how a stable consensus emerges from subjective, expressive, and diverse preference profiles in large-scale decentralised systems.

翻译：社会选择中聚合主观偏好传统上假设存在可信任的中央权威。相比之下，本文形式化了去中心化偏好发现（DPD）：在部分信息、异步交互、抗审查且无中央协调者的条件下，可靠地识别社会选择参数（例如，应用于全局偏好配置文件的聚合规则的规范结果）。为解决DPD问题，我们提出基于八卦传播的框架Snowveil，其中主体反复采样随机对等节点的排名并更新局部信念，以收敛到规范结果。利用势函数、亚鞅理论和集中界，我们证明系统以可调的高概率在有限期望时间内达到该稳定状态。该单一胜者过程可进一步迭代，以构建多胜者场景下的胜选集。Snowveil对特定聚合规则保持无关性，仅要求规则满足正响应性等公理，从而为更广泛的DPD协议提供形式基础。为展示Snowveil的模块化特性，我们引入约束混合波达计数法（CHB）——一种旨在平衡广泛共识与多数支持的聚合规则。我们提供CHB的公理分析，并通过广泛仿真呈现实证结果，验证Snowveil的O(n)可扩展性。总体而言，本工作为大规模去中心化系统中如何从主观、富于表达且多样化的偏好配置文件中涌现稳定共识奠定了基础。