Skip to main content

A Pre-Authentication Mechanism for SSH

Document Type Expired Internet-Draft (individual)
Expired & archived
Author Peter Gutmann
Last updated 2023-06-16 (Latest revision 2022-12-12)
RFC stream (None)
Intended RFC status (None)
Stream Stream state (No stream defined)
Consensus boilerplate Unknown
RFC Editor Note (None)
IESG IESG state Expired
Telechat date (None)
Responsible AD (None)
Send notices to (None)

This Internet-Draft is no longer active. A copy of the expired Internet-Draft is available in these formats:


Devices running SSH are frequently exposed on the Internet, either because of operational considerations or through misconfiguration, making them vulnerable to the constant 3-degree background radiation of scanning and probing attacks that pervade the Internet. This document describes a simple pre-authentication mechanism that limits these attacks with minimal changes to SSH implementations and no changes to the SSH protocol itself.


Peter Gutmann

(Note: The e-mail addresses provided for the authors of this Internet-Draft may no longer be valid.)