A security pattern describes a particular recurring security problem that arises in specific contexts and presents a well-proven generic solution for it. This paper describes an Untraceable Secret Handshake, a protocol that allows two users to mutually verify another’s properties without revealing their identity. The complex security solution is split into smaller parts which are described in an abstract way. The identified security problems and their solutions are captured as SERENITY security patterns. The structured description together with motivating scenarios makes the security solution better understandable for non-security experts and helps to disseminate the security knowledge to application developers.