RFC 644 · UNKNOWN · 1974
MON · 15 JUN 2026
On the problem of signature authentication for network mail
Overview
RFC 644, “On the problem of signature authentication for network mail”, is an Unknown document published in July 1974 by R. Thomas. The canonical text is published by the RFC Editor.
What “Unknown” means
The standards-track status of this early RFC was never formally classified.
Read this RFC
The canonical text of RFC 644 is hosted at rfc-editor.org. Available in TXT,HTML.
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- RFC 645 Network Standard Data Specification syntax
- RFC 642 Ready line philosophy and implementation
- RFC 647 Proposed protocol for connecting host computers to ARPA-like networks via front end processors
- RFC 640 Revised FTP reply codes
- RFC 638 IMP/TIP preventive maintenance schedule
- RFC 637 Change of network address for SU-DSL
- RFC 651 Revised Telnet status option