If you're not interested in money, and just want a crypto related project for a Pi maybe check out "Vanity Addresses". The Pi (whatever version) is quite happy crunching those.

Basically they can make you a bitcoin address personalized with your name/company. For example for my PiNode website my Raspberry Pi made me the address and private key for 1PiNodezERskPzM6iWDfepPxdEWhiKvwm1.

More info https://en.bitcoin.it/wiki/Vanitygen

The software also does litecoin/doge/gamecredits addresses.

If you wanted to make money there is also a vanity address pool with bounties for making addresses other perple have demanded https://vanitypool.appspot.com/availableWork




If you're interested I've made full guides with screenshots on how to set it up at https://pinode.weebly.com/bitcoin-vanity-address.html