expand glossary to explain zombie coins

1 files changed, 41 insertions, 0 deletions

diff --git a/glossary.html.j2 b/glossary.html.j2
index 997f19b6..a90b6c2c 100644
--- a/glossary.html.j2
+++ b/glossary.html.j2
@@ -57,6 +57,20 @@
      Taler's payment service provider.  Issues electronic `coins` during `withdrawal` and redeems them when they are `deposited` by merchants.
     {% endtrans %}
   </dd>
+<dt>{{ _("expired") }}</dt>
+  <dd>
+    {% trans %}
+     Various operations come with time limits. In particular, `denomination keys`
+     come with strict time limits for the various operations involving the
+     `coin` issued under the `denomination`. The most important limit is the
+     `deposit` expiration, which specifies until when wallets are allowed to
+     use the coin in `deposit` or `refreshing` operations. There is also a "legal"
+     expiration, which specifies how long the exchange keeps records beyond the
+     `deposit` expiration time.  This latter expiration matters for legal disputes
+     in courts and also creates an upper limit for `refreshing` operations on
+     special `zombie coin`.
+    {% endtrans %}
+  </dd>
 <dt>{{ _("extension") }}</dt>
   <dd>
     {% trans %}
@@ -98,6 +112,14 @@
      a `coin` is owned by the entity that knows the private key of the coin
     {% endtrans %}
   </dd>
+<dt>{{ _("payback") }}</dt>
+  <dd>
+    {% trans %}
+     operation by which an exchange returns the value of coins affected
+     by a `revocation` to their `owner`, either by allowing the owner to
+     withdraw new coins or wiring funds back to the bank account of the `owner`
+    {% endtrans %}
+  </dd>
 <dt>{{ _("proof") }}</dt>
   <dd>
     {% trans %}
@@ -128,6 +150,12 @@
      operation by which a merchant steps back from the right to funds that he obtained from a `deposit` operation, giving the right to the funds back to the customer
     {% endtrans %}
   </dd>
+<dt>{{ _("revocation") }}</dt>
+  <dd>
+    {% trans %}
+     exceptional operation by which an exchange withdraws a denomination from circulation, either because the signing key was compromised or because the exchange is going out of operation; unspent coins of a revoked denomination are subjected to payback.
+    {% endtrans %}
+  </dd>
 <dt>{{ _("sharing") }}</dt>
   <dd>
     {% trans %}
@@ -188,6 +216,19 @@
      operation by which a `wallet` can convert funds from a reserve to fresh coins
     {% endtrans %}
   </dd>
+<dt>{{ _("zombie coin") }}</dt>
+  <dd>
+    {% trans %}
+     a `coin` is a zombie coin if the coin was (1) used as the `dirty` coin
+     in `refreshing`, (2) the `denomination` of the `fresh` coins created during the
+     `refreshing` was subject to `revocation`, resulting in the `fresh` coin
+     from the refresh operation being subjected to `payback`; as a result,
+     the formerly `dirty` coin is eligible for
+     `refreshing`, even if the dirty coin's denomination is `expired` for
+     deposit operations (but not if it is expired past the legal
+     data retention requirement).
+    {% endtrans %}
+  </dd>
 </dt>
 </div>
 {% endblock body_content %}