C04-CJ: Yes
Rationale
The listener invokes tryHandshake with require_auth=true; ordinary CryptoAuth and Noise admission reject missing or unknown credentials. This supplies a secret-gated response defense under normal admission. The Noise load-defense path can return a cookie before user authorization, so the credit does not imply silence for every unauthenticated probe or complete protocol indistinguishability.
Assessment method
Documentary analysis
Source context
Primary specification / explicit profile inference
Outstanding qualification
Capture invalid, valid-public-key/no-password, guessed-credential and replayed probes in idle and overloaded states. Inspect pre-authorization cookies, known-peer handling and driver replies. Selected UDP peering uses private credentials without public beacon advertisement; no probe experiment performed.