Secure/Multipurpose Internet Mail Extensions (S/MIME) Version 3.2 Message Specification

This document defines Secure/Multipurpose Internet Mail Extensions(S/MIME) version 3.5. S/MIME provides a consistent way to send andreceive secure MIME data. Digital signatures provide authentication,message integrity, and non-repudiation with proof of origin.Encryption provides data confidentiality. Compression can be used toreduce data size. This document obsoletes RFC 5751.