FINDING · DEFENSE
Conjure registration is unidirectional: the client embeds a steganographic ciphertext tag in a complete HTTPS request payload encrypted under a Diffie-Hellman shared secret, and the station passively observes it without sending any reply or spoofing packets. This design makes registration flows indistinguishable from normal HTTPS traffic and enables 25% more viable registration decoys than TapDance by removing the requirement to exclude decoys with short TCP windows or connection timeouts.
From 2019-frolov-conjure — Conjure: Summoning Proxies from Unused Address Space · §4.1 · 2019 · Computer and Communications Security
Implications
- Implement registration as a complete, one-way HTTPS request rather than a half-open or aborted request, so the decoy responds normally and the flow is indistinguishable from routine browsing to any passive observer.
- Avoid station-side responses or TCP spoofing during the registration phase — unidirectional signaling maximizes the usable decoy site pool by eliminating TCP-window and timeout constraints that otherwise shrink it by ~25%.
Tags
Extracted by claude-sonnet-4-6 — review before relying.