http://www.rfc-editor.org/rfc/rfc1115.txt
RFC 1115: Privacy enhancement for Internet electronic mail: Part III - algorithms, modes, and identifiers, J. Linn1989-08-01T23:00:00-00:00This RFC provides definitions, references, and citations for algorithms, usage modes, and associated identifiers used in RFC-1113 and RFC-1114 in support of privacy-enhanced electronic mail. [STANDARDS-TRACK]