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<div>> I think the purpose is to allow both ends to uniquely identify the key. Is there any particular reason of using the first 4 bytes of the digest?</div>
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<div>Using a short identifier (4 bytes) is to keep the packet short for low-power devices. Making a short identifier from the digest is an easy way to get a unique identifier instead of maintaining a separate list of sequential ID numbers. Does that answer
your question?</div>
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<div>- Jeff T</div>
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<span style="font-weight:bold">From: </span>Yingdi Yu <<a href="mailto:yingdi@cs.ucla.edu">yingdi@cs.ucla.edu</a>><br>
<span style="font-weight:bold">Date: </span>Monday, June 8, 2015 at 16:44<br>
<span style="font-weight:bold">To: </span>Jeff Thompson <<a href="mailto:jefft0@remap.ucla.edu">jefft0@remap.ucla.edu</a>><br>
<span style="font-weight:bold">Cc: </span>Marc Mosko <<a href="mailto:Marc.Mosko@parc.com">Marc.Mosko@parc.com</a>>, "<a href="mailto:Ndn-interest@lists.cs.ucla.edu">Ndn-interest@lists.cs.ucla.edu</a>" <<a href="mailto:Ndn-interest@lists.cs.ucla.edu">Ndn-interest@lists.cs.ucla.edu</a>><br>
<span style="font-weight:bold">Subject: </span>Re: [Ndn-interest] Describe the HMAC algorithm in SignatureHmacWithSha256?<br>
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<div class="">Hi Jeff,</div>
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<div class="">On Jun 8, 2015, at 2:57 PM, Thompson, Jeff <<a href="mailto:jefft0@remap.ucla.edu" class="">jefft0@remap.ucla.edu</a>> wrote:</div>
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<div class="">If the application uses a truncated key digest (e.g. the first 4 bytes of the digest), do you think we can still use the KeyDigest field? Or, if we treat the truncated key digest as a KeyId and put it in a Name, should the spec suggest a format
for the Name? </div>
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<div class="">I would prefer to keep KeyDigest literally (i.e., the real sha256 digest of a key), so that it is consistent with other scenarios (e.g., KeyDigest of public key).</div>
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<div class="">For the key name, I think the purpose is to allow both ends to uniquely identify the key. Is there any particular reason of using the first 4 bytes of the digest?</div>
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<div class="">Yingdi</div>
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