The S/MIME Working Group has completed a series of Proposed Standards that comprise the S/MIME version 3.1 specification. As part of the specification update, a new suite of "mandatory to implement" algorithms was be selected. Current efforts update and build upon these base specifications. The Cryptographic Message Syntax (CMS) (RFC 3852) is cryptographic algorithm independent, yet there is always more than one way to use any algorithm. To ensure interoperability, each algorithm should have a specification that describes its use with CMS. Specifications for the use of additional cryptographic algorithms will be developed. CMS, as well as S/MIME version 3 and later, permit the use of previously distributed symmetric key-encryption keys. Specifications for the distribution of symmetric key-encryption keys to multiple message recipients will be developed. Mail List Agents (MLAs) are one use of symmetric key-encryption keys. The specification will be algorithm independent. To aid initial determination of recipient's cryptographic capabilities a specification will be developed allowing S/MIME capabilities to be stored and asserted in X.509 certificates based on the X.509 certificate and CRL profile developed by the PKIX Working Group. The working group will perform necessary interoperability testing to progress the CMS and S/MIME specifications to Draft Standard. The CMS specification depends on the RFC 3280, which was developed by the PKIX working group. This profile must progress to Draft Standard before CMS and the other S/MIME specifications can progress to Draft Standard. Assuming timely progress by the PKIX Working Group, the S/MIME specification can start progressing to Draft Standard in 2005.