Banksy uses a similar system to authenticate his work:<p><a href="https://boingboing.net/2019/03/31/di-faced-note.html" rel="nofollow">https://boingboing.net/2019/03/31/di-faced-note.html</a>
The key part here seems to be protection against all kinds of message interception attacks - if I listen in on the conversation and hear that the code is 12345678, then I can't easily create a dollar bill with that code on it, and probably even the FBI can't do it quickly enough for it to be useful.
How many drops tried to claim they didn't get any money or that the courier forged a receipt before they invented physical nonrepudiation?<p>And it's nonrepudiation without identity, the identifying info is destroyed in the transaction.<p>The courier could just take a cell phone photo of the drop, but no one wants that evidence trail. One time use serials are perfect.<p>And despite some characterizations, seems to me like uniqueness is more important than randomness here, which is good, because serial numbers are better at that.
So a dollar bill is an inexpensive (on the scale of crime) sheet of paper pre-printed with a unique number that's somewhat difficult to forge. If you rip it up, that number won't be used again.<p>How are they making use of this feature set? I'd like to see a diagram with arrows and stuff.
I can’t find any direct evidence now, but I remember hearing (probably in the 80’s) that one of the ideas suggested for assigning Ethernet MAC addresses was to use dollar bill serial numbers, to avoid having to set up and run a central registry forever. However, it’s technically illegal to destroy currency and the cost of $1 per address would eventually become uneconomic.
I'd love to see a detailed list of the features of this dollar exchange system that make it preferable to any of the relevant software systems currently in existence.<p>My guess is that such a list can generalize to HCI and help reveal some of the garbage assumptions behind a lot of common software (esp. cryptography-related software).
Back un college se used as fandom seeds the first word and page number of a dictionary someone left behind long ago....<p>SSL certificate passwords were easy to remember as long as nobody removed the bookmark no that useless dictionary.
In other words, the best delivery receipt is still a bounty on your head--and entire family line--if you try to get cute. But this serves to identify the "cowboys"