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<div class="moz-cite-prefix">On 2/6/23 21:12, Phillip Hallam-Baker
wrote:<br>
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<div class="gmail_default" style="font-size:small">I am trying
to work out what the name of the thing I am writing is.</div>
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<div class="gmail_default" style="font-size:small">OK so we have</div>
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<div class="gmail_default" style="font-size:small">Digital
signature - base class</div>
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<div class="gmail_default" style="font-size:small">Multi-Signature
- A single piece of data signed under multiple private keys,
all of which are required for the signature to be considered
valid.</div>
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<p>I would call this type a 'consensus signature' - the basic unit
of action of of a body which must come to a unanimous agreement to
act, like a jury etc. </p>
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<div class="gmail_default" style="font-size:small">Quorum
signature - A multi-signature where t of n sigs must be
present</div>
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<p>There's a special case, because in committee proceedings a quorum
is some threshold number of votes, and does not usually require
that those votes are unanimously in favor. A quorum that requires
ten votes takes valid action even if six of them voted yes and
four voted no or abstained, out of the 20 or however many could
have voted. A 'quorum' shows that a certain number of people (or
agents) have paid attention to the question, but the emergent
action does not necessarily require all of those people to have
been in agreement. <br>
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<div class="gmail_default" style="font-size:small">Threshold
signature - A digital signature created from a private key
split into t of n shares.</div>
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<p>I think that one's well established.<br>
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<div class="gmail_default" style="font-size:small">Merkle
Signatures, Tree Signatures, Lamport Signatures, all used to
refer to symmetric key based signatures.</div>
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<p>And still do. The adaptation of these to asymmetric keys changes
their properties enough that I think as an author you have to
mention which variety you're talking about on just about every
page you mention them. <br>
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<div class="gmail_default" style="font-size:small">What I have
is a sequence of envelopes and a signature on the apex of a
Merkle tree and I am extracting a specific envelope and the
apex signature and the parts necessary to reconstruct the
digest chain for that envelope. What do we call such a
signature that we haven't already used?</div>
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<div class="gmail_default" style="font-size:small">There are two
cases,</div>
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<div class="gmail_default" style="font-size:small">Signature on
envelope #42, signing envelope #10</div>
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<div class="gmail_default" style="font-size:small">Signature on
envelope #42, signing envelope #10, #32, #40<br>
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<div class="gmail_default" style="font-size:small">The overall
requirement is to provide a proof that document P was signed
After document X but before Document Y. Where X has been
enrolled in a Trusted external notary chain and Y incorporates
an output from that chain.</div>
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<div class="gmail_default" style="font-size:small">So if I am
trying to show that I collected a set of forensics data on a
particular date, documents X and Y probably involve a DoJ or
NIST notary chain, either directly or indirectly. If you run
your own notary log, the trusted party can be yourself (if you
were active at the time with sufficient granularity).</div>
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<div class="gmail_default" style="font-size:small">Interval
Signature???</div>
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<p>I think 'interval signature' is probably a good nomenclature for
that because it corresponds to things that happened within some
interval in a (chronological) Merkle Tree. <br>
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<p>Bear</p>
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