Secure/ Multipurpose Internet Mail Extensions (s/mime)

Primary definition

A set of specifications for securing electronic mail. 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). Source: NIST SP 800-49

Also known asSecure MIME · S-MIME
2 sources cited4 related termsReviewed Aug 10, 2026
Committee on National Security Systems Glossary CNSSI 4009-2015View source

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CNSSGC

A set of specifications for securing electronic mail. 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). Source: NIST SP 800-49

Committee on National Security Systems Glossary CNSSI 4009-2015 · 2024

Cite this term

Permanent URL · stable across revisions
Election Security Glossary. (2026). Secure/ Multipurpose Internet Mail Extensions (s/mime). In Election Security Glossary. Retrieved August 21, 2026, from https://electionsecurityglossary.com/glossary/secure-multipurpose-internet-mail-extensions-s-mime

Sources

2 cited · last checked Aug 10, 2026

01

Committee on National Security Systems Glossary CNSSI 4009-2015
Committee on National Security Systems Glossary CNSSI 4009-2015

High consensus

View source

02

The Cyber Glossary
The Cyber Glossary

Multi-source

View source

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