S/MIME & PGP: Security through Message-Oriented Encryption

• Guide to Using S/MIME (mozilla.org)
• Using S/MIME E-mail (Dartmouth Computing)
• How I Sign and Encrypt E-mail with Pretty Good Privacy (PGP) (Weldon Whipple)

RFCs

Pretty Good Privacy

• RFC 1991 (PGP)
• RFC 2015 (MIME Security with Pretty Good Privacy (PGP))
• RFC 2440 (OpenPGP)

Secure MIME

• RFC 2633 (S/MIME Version 3)
• RFC 2634 (Enhanced S/MIME)

Privacy Enhanced Mail

• RFC 1421 (PEM I: Message Encryption and Authentication)
• RFC 1422 (PEM II: Certificate-Based Key Management)
• RFC 1423 (PEM III: Algorithms, Modes, and Identifiers)

MIME Object Security Services

• RFC 1848 (MOSS)