Challenge: Questionable Encryption Algorithm

[jonnin]

that is a fat way of doing it (which is fine for encryption). Some home-cooked form of UUEncode would cut the space wasting, but maybe its not important.

[mbozzi]

This is how BIP-39 encodes private key bits into a string easily copied by humans. E.g. "boring wolf accident add select anchor hope gossip correct jacket boring that vote cotton hope" encodes 64 bytes.

Nice. It's certainly better than base64 or something. (If you're a human.)