FINDING · DETECTION
If an adversary replays captured client handshake traffic to a decoy host under adversary control, and the decoy router attempts to resume the client's session on that host, the adversary can infer that a decoy router is present on the path to the original decoy host. The paper identifies this as a residual probing vulnerability when the client does not encrypt the destination server to which resumption should be directed.
From 2018-manfredi-multiflow — MultiFlow: Cross-Connection Decoy Routing using TLS 1.3 Session Resumption · §3.1 · 2018 · Free and Open Communications on the Internet
Implications
- Encrypt the target resumption server identity within the covert channel before the decoy router attempts resumption, preventing an adversary-controlled decoy host from inferring decoy router presence.
- Rate-limit or restrict resumption attempts to known-safe destination servers to reduce exposure from adversary-replay probes.
Tags
Extracted by claude-sonnet-4-6 — review before relying.