Subject: [Tsvwg] I-D Action:draft-ietf-tsvwg-port-randomization-01.txt

From: [email-masked]
Date: Mon, 25 Feb 2008 14:00:01 -0800 (PST)

A New Internet-Draft is available from the on-line Internet-Drafts directories.
This draft is a work item of the Transport Area Working Group Working Group of the IETF.

	Title           : Port Randomization
	Author(s)       : M. Larsen, F. Gont
	Filename        : draft-ietf-tsvwg-port-randomization-01.txt
	Pages           : 25
	Date            : 2008-02-25

Recently, awareness has been raised about a number of "blind" attacks
that can be performed against the Transmission Control Protocol (TCP)
and similar protocols.  The consequences of these attacks range from
throughput-reduction to broken connections or data corruption.  These
attacks rely on the attacker's ability to guess or know the five-
tuple (Protocol, Source Address, Destination Address, Source Port,
Destination Port) that identifies the transport protocol instance to
be attacked.  This document describes a simple and efficient method
for random selection of the client port number, such that the
possibility of an attacker guessing the exact value is reduced.
While this is not a replacement for cryptographic methods, the
described port number randomization algorithms provide improved
security/obfuscation with very little effort and without any key
management overhead.  The mechanisms described in this document are a
local modification that may be incrementally deployed, and that does
not violate the specifications of any of the transport protocols that
may benefit from it, such as TCP, UDP, SCTP, DCCP, and RTP.

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