Draft ISO verification strategies

wiki/src/blueprint/bootstrapping/browser_extension.mdwn

@@ -70,6 +70,17 @@ ISO verification
     - Otherwise it shows the result in a popup message and points to the
       appropriate page.
 
+ISO verification mechanisms
+===========================
+
+We're considering three possible verification mechanisms, each of those
+have to be checked against feasibility. By order of preference:
+
+  A. OpenPGP signature verification, against our signing key included in
+     the extension.
+  B. Checksum correlation against boum.org and an other site.
+  C. Checksum against boum.org
+
 Other desirable features
 ========================