Two nights ago I couldn’t sleep and ran across Doug Crockford’s Human Error Resistant Base32 encoding. This kind of twiddling is fun so I wrote an implementation in Common Lisp. However, there only seem to be a few implementations out there (one I found in Perl gives identical results, one in Python pads to an even-length with leading zeros) so it’s mostly tested against itself and some scribbling on paper. Developed on SBCL, lightly tested on CCL and ECL so should work on others (ignoring my attempts at optimization).
Download here base32-crockford.lisp