RFC 2949 · PROPOSED STANDARD · 2000
SUN · 14 JUN 2026
Telnet Encryption: CAST-128 64 bit Output Feedback
Overview
RFC 2949, “Telnet Encryption: CAST-128 64 bit Output Feedback”, is a Proposed Standard document published in September 2000 by J. Altman. The canonical text is published by the RFC Editor.
Abstract
This document specifies how to use the CAST-128 encryption algorithm in output feedback mode with the telnet encryption option. Two key sizes are defined: 40 bit and 128 bit. [STANDARDS-TRACK]
What “Proposed Standard” means
An entry-level standards-track specification: stable, peer-reviewed and a solid basis for implementation, though it may still evolve before becoming an Internet Standard.
Read this RFC
The canonical text of RFC 2949 is hosted at rfc-editor.org. Available in TXT,HTML.
Other RFCs from 2000
- RFC 2948 Telnet Encryption: DES3 64 bit Output Feedback
- RFC 2950 Telnet Encryption: CAST-128 64 bit Cipher Feedback
- RFC 2947 Telnet Encryption: DES3 64 bit Cipher Feedback
- RFC 2951 TELNET Authentication Using KEA and SKIPJACK
- RFC 2946 Telnet Data Encryption Option
- RFC 2952 Telnet Encryption: DES 64 bit Cipher Feedback
- RFC 2945 The SRP Authentication and Key Exchange System
- RFC 2953 Telnet Encryption: DES 64 bit Output Feedback