CompTIA Security+ All-in-One Exam Guide (Exam SY0-301), 3rd Edition, 3rd Edition

S/MIME

The Secure/Multipurpose Internet Mail Extensions (S/MIME) message specification is an extension to the MIME standard that provides a way to send and receive signed and encrypted MIME data. RSA Security created the first version of the S/MIME standard, using the RSA encryption algorithm and the PKCS series of standards. The second version dates from 1998 but had a number of serious restrictions, including the restriction to 40-bit Data Encryption Standard (DES). The current version of the IETF standard is dated July 2004 and requires the use of Advanced Encryption Standard (AES).

The changes in the S/MIME standard have been so frequent that the standard has become difficult to implement. Far from having a stable standard for several years ...