Network Security: Private Communication in a Public World, Second Edition

20. Electronic Mail Security

This chapter gives an overview of the issues involved in making electronic mail secure. First we discuss non-security-related issues such as distribution lists and mail forwarders. Then we list various security features, and in the remainder of the chapter we describe how each of these features might be implemented. A lot of the techniques are equally applicable to encrypting or integrity-protecting any sort of data, such as files kept on a file server or data stored on backup media. In the following chapters we discuss particular secure mail standards—S/MIME, PEM, and PGP. Another standard, X.400, was a collaboration between CCITT and ISO. The security aspects of it were never fully specified and never caught on, ...