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 Untraceable Secret Handshakes, cryptographic protocols that allow two users to mutually verify another's properties without revealing their identity or other sensitive information. 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 from three different domains makes the security solution better understandable for non-security experts and helps to disseminate the security knowledge to application developers.