Embedding explicit TTL values in mesh-routed messages leaks proximity information — a recipient can infer that a high-TTL message originator was recently nearby. MIRAGE mitigates this with memoryless TTLs: carriers independently discard messages with probability q per epoch, implementing a branching process with replication factor R ≤ nmax·(1−q). Setting q > 1 − 1/nmax ensures sub-critical message extinction with expected lifetime ≈ −ln(nmax)/ln(R) epochs.
From 2026-ratliff-mirage — Mirage: Private, Mobility-based Routing for Censorship Evasion
· §VI-C
· 2026
· Network and Distributed System Security
Implications
Any protocol that embeds hop-count or TTL metadata in forwarded messages allows passive observers to reconstruct proximity graphs and infer originator identity — use memoryless expiry mechanisms (probabilistic drop per epoch) instead of decrementing counters.
Tune (nmax, q) jointly to bound both message lifetime and network load; the analytic relationship E[Xj] ≤ nmax·Rʲ allows operators to derive these parameters directly from target delivery window and bandwidth budget.