S/mime

Primary definition

A set of specifications for securing electronic mail. Secure/ Multipurpose Internet Mail Extensions (S/MIME) is based upon the widely used MIME standard and describes a protocol for adding cryptographic security services through MIME encapsulation of digitally signed and encrypted objects. The basic security services offered by S/MIME are authentication, non-repudiation of origin, message integrity, and message privacy. Optional security services include signed receipts, security labels, secure mailing lists, and an extended method of identifying the signer's certificate(s). (SP 800-49) (NISTIR)

Also known asSecure/Multipurpose Internet Mail Extensions
1 sources cited4 related termsReviewed Aug 10, 2026
The Cyber GlossaryView source

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TCG

A set of specifications for securing electronic mail. Secure/ Multipurpose Internet Mail Extensions (S/MIME) is based upon the widely used MIME standard and describes a protocol for adding cryptographic security services through MIME encapsulation of digitally signed and encrypted objects. The basic security services offered by S/MIME are authentication, non-repudiation of origin, message integrity, and message privacy. Optional security services include signed receipts, security labels, secure mailing lists, and an extended method of identifying the signer's certificate(s). (SP 800-49) (NISTIR)

The Cyber Glossary · 2024

Cite this term

Permanent URL · stable across revisions
Election Security Glossary. (2026). S/mime. In Election Security Glossary. Retrieved August 13, 2026, from https://electionsecurityglossary.com/glossary/s-mime

Sources

1 cited · last checked Aug 10, 2026

01

The Cyber Glossary
The Cyber Glossary

Single-source

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