  This paper describes a new protocol for authentication in ad-hoc networks.
The protocol has been designed to meet specialized requirements of ad-hoc
networks, such as lack of direct communication between nodes or requirements
for revocable anonymity. At the same time, a ad-hoc authentication protocol
must be resistant to spoofing, eavesdropping and playback, and
man-in-the-middle attacks. The article analyzes existing authentication methods
based on the Public Key Infrastructure, and finds that they have several
drawbacks in ad-hoc networks. Therefore, a new authentication protocol, basing
on established cryptographic primitives (Merkle's puzzles and zero-knowledge
proofs) is proposed. The protocol is studied for a model ad-hoc chat
application that provides private conversations.
