2025-sharma-cenpush
CenPush: Blocking-Resistant Control Channel Using Push Notifications
Abstract
Maintainers of circumvention tools must continuously push fresh
client configuration and proxy IPs to users in censored regions, but
existing update channels rely on clients explicitly polling
out-of-band endpoints — channels that are themselves easy to block.
CenPush flips this around by using mobile platform push-notification
services (already widely deployed and difficult to block without
large collateral damage) as a one-way control channel from tool
maintainer to client. The authors present a general design for
integrating push notifications into circumvention tools as a
blocking-resistant control plane, then implement and evaluate it
for Tor — pushing fresh bridge lines to clients without any
client-initiated query.
Team notes
The push-notification control-channel design is directly relevant to
Lantern's bridge / outbound rotation: a similar mechanism could push
fresh proxy configs to clients without relying on a polled config
endpoint that censors can block.