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UpdatedPROPOSED STANDARDIETF stream

RFC 4251: The Secure Shell (SSH) Protocol Architecture

Still current, but amended. Parts of this document are changed or extended by RFC 8308, RFC 9141. Read both.

In plain English — editorial summary, not part of the RFC

The Secure Shell (SSH) Protocol is a protocol for secure remote login and other secure network services over an insecure network. This document describes the architecture of the SSH protocol, as well as the notation and terminology used in SSH protocol documents. It also discusses the SSH algorithm naming system that allows local extensions. The SSH protocol consists of three major components: The Transport Layer Protocol provides server authentication, confidentiality, and integrity with perfect forward secrecy. The User Authentication Protocol authenticates the client to the server. The Connection Protocol multiplexes the encrypted tunnel into several logical channels. Details of these protocols are described in separate documents. [STANDARDS-TRACK]

Document record

Document ID
RFC4251
Published
January 2006
Authors
T. Ylonen; C. Lonvick
Status
PROPOSED STANDARD
Stream
IETF
Area
sec
Pages
30
Also known as
—
Updated by:
RFC 8308, RFC 9141

Topics

Referenced by

2 later RFCs formally update or obsolete part of this document.

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About this page

The document record above — title, authors, date, status, stream, area, relationships, DOI and errata — is imported verbatim from the public RFC Editor index. The “in plain English” section is editorial: written by The metasystema editorial team, not part of the RFC. Where the two differ, the RFC text governs.

Last checked against the RFC Editor index on . RFCs are never revised after publication; changes are issued as new documents.

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canonical URL: /rfc/4251-the-secure-shell-ssh-protocol-architecture