Subject: I-D ACTION:draft-matsuura-sign-mode-01.txt

From: [email-masked]
Date: Tue, 14 Sep 1999 06:55:42 -0400

A New Internet-Draft is available from the on-line Internet-Drafts directories.

	Title		: A revised signature mode for the Internet Key Exchange
	Author(s)	: K. Matsuura, H. Imai
	Filename	: draft-matsuura-sign-mode-01.txt
	Pages		: 9
	Date		: 13-Sep-99
	
Phase 1 of the Internet Key Exchange (IKE) [HC98] has several modes
with different number of message passes. For those who want to save
their bandwidth, three-pass Aggressive Mode is a good choice since
it has minimal number of message passes in Phase 1.
The public-key primitive method in Aggressive Mode provides
significant security advantages over the other alternatives and
should be the method of choice in many implementations. In this
method, however, the responder must pay computational cost as
expensive as modular exponentiation BEFORE identifying the
initiator. This feature can be abused by malicious initiators for a
Denial-of-Service (DoS) attack. The purpose of this document is to
solve this problem in digital-signature method by using falling-
together (FT) mechanism [MI98], [MI99] in conjunction with
stateless-connection technique [AN97] and an appropriate use of
Cookies [KS99].
Remark: This document is NOT self-contained, it is intended as an
addendum to the authentication methods defined in [HC98]. In
particular, it uses notation and definitions of [HC98]. Thus, it is
best read in conjunction with [HC98].

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