  This document describes a best-effort delay-tolerant communication system
that protects the privacy of users in wireless ad-hoc networks by making their
communication undetectable. The proposed system is a wireless broadcast-based
adaptation of mix networks where each user belongs to at least one group it
trusts, and each group acts as a mix node. Assuming encryption is not broken,
it provides undetectability of all users and messages against external
adversaries, as well as undetectability of users and messages in
non-compromised groups against internal adversaries.
