A specialist in Internet security, Rescorla explains secure sockets layer and its IETF successor, transport layer security, which are leading Internet security protocols. He discusses their role in network communications, their security properties, and their performance characteristics. He warns that they cannot be treated as a black box to plug systems into, but must be understood quite thoroughly to be used effectively. The bibliography is lightly annotated. Annotation c. Book News, Inc., Portland, OR (booknews.com)