Cash: paper lasts a few years at best, coins are worth less than the metal they're minted from, armored vans for transport and entire law enforcement departments dedicated to counterfeiting
I've handled plenty of bills that are as old, or older, than I am. Paper currency gets a little more than a 'few years'. You don't see a big recovery effort until the denomination gets redesigned to be harder to forge (making the older bills less desirable, though equal in value in commerce), so many of the older bills remain in circulation. Not everyone beats up their money in the literal sense.
I'd rather have a phone that has a software-swappable identifier that handshakes with the tower, but I suppose that is just dreaming.
Similar to the good old days of the ESN (think Analog, TDMA, CDMA)? Granted, the ESN was printed right in the back of the thing, and all someone needed was a few minutes to get that (at most) and cloning isn't far behind--not that the GSM method is unclonable, but really, it's more often going to be easier to just yoink someone's SIM and use it while you can.
You also lose the benefit of being able to just switch to a different phone on your own if the identifier is a value stored in the phone--every phone would have to have it's own identifier on the network (letting multiple phones share the same would make it hard to claim cloning with your provider, should it happen--it's built in for multiple phones to say they're the same person at that point), so if you wanted or needed to change handsets, it's another call to your provider.
BECAUSE BILLY "FFUCKING" MAYSSS sayd it works!
He's dead, Jim!
Now, just get Michael on the plane and he can be done with Purgatory.
less to do with each other than an Orthodox rabbi and a porkchop.
This will now replace 'What does X have to do with the price of tea in China' in my daily conversation. You almost got a beverage spray from me because this bit of wit.
I've noticed several design suggestions in your code.