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<p>On 10/2/2017 11:05 AM, Phillip Hallam-Baker wrote:<br>
</p>
<blockquote type="cite"
cite="mid:CAMm+Lwg34CURjdwij8NCSRt6mvNw806BbpUDKPJsakq_OGz9xg@mail.gmail.com">
<div class="gmail_default" style="font-size:small">So I was
working on my UDF fingerprint scheme. Using base32 to encode a
fingerprint and adding an 8 byte version prefix means that a
fingerprint with a 117 bit work factor looks like this:</div>
<div class="gmail_default" style="font-size:small"><br>
</div>
<div class="gmail_default" style="font-size:small"><span
style="font-family:"Noto
Sans",Arial,Helvetica,sans-serif;font-size:14px">MDDK7-N6A72-7AJZN-OSTRX-XKS72</span><br>
</div>
<div class="gmail_default" style="font-size:small"><span
style="font-family:"Noto
Sans",Arial,Helvetica,sans-serif;font-size:14px"><br>
</span></div>
<div class="gmail_default" style="font-size:small"><span
style="font-family:"Noto
Sans",Arial,Helvetica,sans-serif;font-size:14px">Its not
bad but how about we ease up on the work factor. The absolute
minimum I would want to have is 92 bits.</span></div>
<div class="gmail_default" style="font-size:small"><span
style="font-family:"Noto
Sans",Arial,Helvetica,sans-serif;font-size:14px"><br>
</span></div>
<div class="gmail_default" style="font-size:small"><span
style="font-family:"Noto
Sans",Arial,Helvetica,sans-serif;font-size:14px">Now
suppose that the first 25 bits of the fingerprint are zeros. </span><span
style="font-family:"Noto
Sans",Arial,Helvetica,sans-serif;font-size:14px">The 92
bit fingerprint that would look like this:</span></div>
<div class="gmail_default" style="font-size:small"><span
style="font-family:"Noto
Sans",Arial,Helvetica,sans-serif;font-size:14px"><br>
</span></div>
<div class="gmail_default" style="font-size:small"><span
style="font-family:"Noto
Sans",Arial,Helvetica,sans-serif;font-size:14px">MAAAA-AB3VV-FOFE2-CLRWJ </span><span
style="font-family:"Noto
Sans",Arial,Helvetica,sans-serif;font-size:14px"><br>
</span></div>
<div class="gmail_default" style="font-size:small"><span
style="font-family:"Noto
Sans",Arial,Helvetica,sans-serif;font-size:14px"><br>
</span></div>
<div class="gmail_default" style="font-size:small"><span
style="font-family:"Noto
Sans",Arial,Helvetica,sans-serif;font-size:14px">Now
looks like this:</span></div>
<div class="gmail_default" style="font-size:small"><span
style="font-family:"Noto
Sans",Arial,Helvetica,sans-serif;font-size:14px"><br>
</span></div>
<div class="gmail_default" style="font-size:small"><span
style="font-family:"Noto
Sans",Arial,Helvetica,sans-serif;font-size:14px">MF3VV-FOFE2-CLRWJ </span><span
style="font-family:"Noto
Sans",Arial,Helvetica,sans-serif;font-size:14px"><br>
</span></div>
</blockquote>
<br>
Both the idea and the implementation are very close to the "call
signs" system that I worked on with Kim Cameron and Josh Benaloh.
Too bad that we failed to publish an academic paper, and that the
best description is in the patent --
<a class="moz-txt-link-freetext" href="https://www.google.com.au/patents/US7929689">https://www.google.com.au/patents/US7929689</a>.<br>
<br>
<pre class="moz-signature" cols="72">--
Christian Huitema</pre>
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