An adversary who wishes to expose storers by having forwarders log storer identities must compromise all n−k+1 chosen forwarders before or during the publication event; forwarders that legitimately delete the storer mapping immediately after acknowledging publication render this attack ineffective unless the adversary pre-positions malicious nodes at sufficient density. The paper notes that with a reasonably large forwarder population the probability of the required simultaneous compromise is small.
From 2002-serjantov-anonymizing — Anonymizing Censorship Resistant Systems
· §3
· 2002
· International Workshop on Peer-To-Peer Systems
Implications
Enforce immediate, irreversible state deletion at forwarders the moment publication acknowledgment is sent — the forget step is a load-bearing security invariant, not an optimization.
Increase forwarder count n to reduce the per-publication probability that all n−k+1 selected forwarders are simultaneously adversarial; this is an adjustable security parameter independent of the secret-sharing threshold k.