Ollam, a security auditor and lock-penetration specialist who is also on the board of The Open Organization Of Lockpickers, presents a more advanced text on lock-picking that follows his Practical Lock Picking 2nd Edition. Here he focuses on impressioning, which is the art cum science of transforming blank keys into functional ones by assessing the structure and operation of a given lock. As with his previous book, Ollam stresses that one should not manipulate locks that are not their own or that they rely upon. Written for rigorous self-study or use in a class, each chapter is highly structured, including diagrams and figures, tips and tricks, introductions and summaries. He explains the rationale for and basic premises of impressioning; how to utilize different medium for making impressions; how to decode keys; how master-keyed systems work; how overlifting pins works; and how to make skeleton keys, bump keys, and smartkeys. Syngress Media is an imprint of Elsevier. Annotation ©2013 Book News, Inc., Portland, OR (booknews.com)