On Fri, Oct 31, 2014 at 2:57 PM, Dave Horsfall <dave@horsfall.org> wrote:

On Fri, 31 Oct 2014, Harald Hanche-Olsen wrote:

...

Are you perhaps thinking of the so-called EURion constellation?

https://en.wikipedia.org/wiki/EURion_constellation

That *could* be it; I'd heard a few different versions of the story that some copiers would not do currency, and naturally the banks themselves are going to be less than forthcoming about their techniques (just like in the crypto world).

http://www.secretservice.gov/know_your_money.shtml Quality counterfeiters of US notes don't care what BEP/FED/TREAS discloses, they just reverse engineer the bills. Also note that bills before 1990 have nearly trivial security and are still legal tender. There is a model year vs. timespan "ain't seen one of those lately" acceptance risk with older bills but that's about it. Either way, don't worry, your average gov't deflates bill value by printing, more than any counterfeit factory ever would want to. Note that paper money can be cloned with far less cost than any known attack on say Bitcoin, and with more profit since you still have the bills, but unless you can steal a tiny percent of the coins quietly all you'd do is bring the network trust to zero.