Use this button for decoding the
headers of PGP sigs and keys:
The way it works is that every three 8-bit bytes are stored in
four 6-bit characters, where the characters are in the range
[A-Z][a-z][0-9][+/]. (Count 'em up; that's 64 total characters). Since this
doesn't exactly line up, pad characters of [=] are used at the very end.