Identity-based encryption (IBE) is a new technology that allows the identity of users to be used as cryptographic keys instead of the long, random strings of bits that earlier technologies required. This allows for the creation of cryptographic systems that are as secure as traditional systems, but are much simpler and easier to use. Until now, details on IBE have only been found in cumbersome, hard-to-follow journal articles and conference proceedings. This is the first book to offer complete, accessible guidance on the subject. It provides professionals and students with an in-depth understanding of IBE, and offers practitioners a wealth of practical techniques, algorithms and numerous worked examples to help them effectively implement this technology in the field.