This library implements the base58 encoding algorithm. It's basically base64 but with a smaller alphabet (58, as in the title) that doesn't include similar looking characters, among other things.
The implementation is essentially a carbon copy of Gavin Andresen's Python code.
cl-user> (base58:encode "this is a test") "jo91waLQA1NNeBmZKUF" cl-user> (base58:decode "jo91waLQA1NNeBmZKUF") "this is a test"
The encoded strings in the tests were created with Andresen's unmodified code, so they are correct. Probably.
Copyright (c) 2014 Fernando Borretti (firstname.lastname@example.org)
Licensed under the MIT License.