<?xml version="1.0" encoding="UTF-8"?>
<reference anchor="I-D.chuang-replay-resistant-arc" target="https://datatracker.ietf.org/doc/html/draft-chuang-replay-resistant-arc-11">
   <front>
      <title>Replay Resistant Authenticated Receiver Chain</title>
      <author initials="W." surname="Chuang" fullname="Wei Chuang">
         <organization>Google, Inc.</organization>
      </author>
      <author initials="B." surname="Gondwana" fullname="Bron Gondwana">
         <organization>Fastmail Pty Ltd</organization>
      </author>
      <date month="February" day="20" year="2024" />
      <abstract>
	 <t>   DKIM (RFC6376) is an IETF standard for the cryptographic protocol to
   authenticate email at the domain level and protect the integrity of
   messages during transit.  Section 8.6 defines a vulnerability called
   DKIM Replay as a spam message sent through a SMTP MTA DKIM signer,
   that then is sent to many more recipients, leveraging the reputation
   of the signer.  We propose a replay resistant cryptographic based
   protocol that discloses all SMTP recipients and signs them, allowing
   a receiver or any third party to verify that the message went to the
   intended recipient.  If not then then potentially the message is
   replayed.  Moreover it leverages ARC (RFC8617) and sender defined
   forwarding path to build a &quot;chain of custody&quot; that accurately defines
   the SMTP forwarding path of the message.  This also allows the
   protocol to detect DKIM and ARC replay attacks and other attacks.

	 </t>
      </abstract>
   </front>
   <seriesInfo name="Internet-Draft" value="draft-chuang-replay-resistant-arc-11" />
   
</reference>
