Differentially Private Condorcet Voting

Designing private voting rules is an important and pressing problem for trustworthy democracy. In this paper, under the framework of differential privacy, we propose a novel famliy randomized based on well-known Condorcet method, focus three classes in family: Laplacian method (CMLAP), exponential (CMEXP), response (CMRR), where λ represents level noise. We prove that all our satisfy absolute monotonicity, lexi-participation, probabilistic Pareto efficiency, approximate criterion, SD-strategyproofness. addition, CMRR satisfies (non-approximate) while CMLAP CMEXP strong lexi-participation. Finally, regard privacy as axiom, discuss its relations to other axioms.