MIME Object Security Service (MOSS) is an IP protocol for end-to-end encryption and digital signature for Multipurpose Internet Mail Extensions (MIME) message content. MOSS is more of a framework than a standard for formatting a MIME message.
MOSS uses symmetric encryption for content and asymmetric encryption for key transmissionand signature. For the digital signature, MOSS uses the multipart signing and multipart encryption framework of the MIME protocol. The services reside at the application layer and support end-to-end encryption( E2EE) between communication partners.