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Challenge / Response Interworking (CRI) Framework for Challenge / Response Email Systems

Document Type Expired Internet-Draft (asrg RG)
Authors Eric Dean , Yakov Shafranovich
Last updated 2003-09-23
Stream Internet Research Task Force (IRTF)
Intended RFC status (None)
Expired & archived
Stream IRTF state (None)
Consensus boilerplate Unknown
Document shepherd (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This Internet-Draft is no longer active.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:


SMTP was designed simply to deliver email messages without authenticating sources or senders of email messages. In an affort to reduce spam on the Internet, Challenge/Response ('C/R') email systems were developed to provide a method for validating message origination for an intended recipient. This document defines a Challenge / Response Interworking ('CRI') protocol by proposing the use of SMTP extensions and MIME headers for interoperability of C/R systems. This document also defines a set of guidelines for continued use with existing non-CRI mail systems and clients.


Eric Dean
Yakov Shafranovich

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