Exact Jensen–Shannon Asymptotics for Shuffle Privacy Under Partial Linkability

Exact information-theoretic framework for shuffle model privacy under partial linkability — when some messages can be linked via side-channels or timing attacks. Key result: The Anonymity Renewal Theorem shows that without per-round identifier renewal, privacy degrades catastrophically — over a billion-fold in 5 rounds. Includes exact JSD asymptotics, finite-n bounds, Gaussian extension, and design guidelines.