This page is obsolete and should be updated

S/MIME (Secure / Multipurpose Internet Mail Extensions) is a standard for public key encryption and signing of e-mail encapsulated in MIME. S/MIME was originally developed by RSA Data Security Inc. The original specification used the recently developed IETF MIME specification with the de facto industry standard PKCS #7 secure message format.

Change control to S/MIME has since been vested in the IETF and the specification is now layered on Cryptographic Message Syntax, an IETF specification that is identical in most respects with PKCS #7. Now, S/MIME is a RFC standard:

  • RFC 2630- Cryptographic Message Syntax
  • RFC 2631- Diffie-Hellman Key Agreement Method
  • RFC 2632- S/MIME Version 3 Certificate Handling
  • RFC 2633- S/MIME Version 3 Message Specification

Further reading