Consider changing the severity of warnings based on whether a previous key exists.

[danwent]

The idea being that a quorum duration of 0 for a site which notaries do not have any past information on is less suspicious than a quorum duration of 0 when the site has previously used another key.

[ghost]

How can I reproduce such a response? (Btw: Do you have a development server we can instruct to give specific responses?) How likely is it that a notary doesn't have any past information? (I have to admit I don't know how the notaries work right now. Do they just scrap the web on a daily basis or just visit sites on demand, or on a daily basis once they got a demand?)

In notaryAjaxCallback() the variable server_result has type:

{ obs : [ key : "...hex key...", key_type : "ssl", timestamps : [ { start : "1234567890", end : "9876543210" } ]
, server : "notary.example.com:80"
, signature : "... base64 public key ..."
}

thus one can check if such a response is received via:

if(server_result.obs == null || server_result.obs.length === 0) { debugger; alert("empty response"); }