Censorship Resistance: Let a Thousand Flowers Bloom?

TL;DR

This paper models the decision-making process in censorship resistance systems as a game, showing that the optimal strategy depends on the censor's tolerance for false positives and negatives, and emphasizing the importance of understanding the censor's utility.

Contribution

It introduces a game-theoretic model for selecting censorship resistance strategies based on the censor's utility and tolerance levels, highlighting the need to understand the censor's preferences.

Findings

Choosing a single system is optimal if false positive tolerance is low.

Multiple systems are preferable if false positive tolerance is high.

Traffic distribution depends on the censor's false negative tolerance.

Abstract

This paper argues that one of the most important decisions in designing and deploying censorship resistance systems is whether one set of system options should be selected (the best), or whether there should be several sets of good ones. We model the problem of choosing these options as a cat-and-mouse game and show that the best strategy depends on the value the censor associates with total system censorship versus partial, and the tolerance of false positives. If the censor has a low tolerance to false positives then choosing one censorship resistance system is best. Otherwise choosing several systems is the better choice, but the way traffic should be distributed over the systems depends on the tolerance of the censor to false negatives. We demonstrate that establishing the censor's utility function is critical to discovering the best strategy for censorship resistance.