Like base64, but without these characters: +/0O1l
This is the definition of base58 as used by bitcoin. (there is apparently a different version of base58 used by Flickr)
The rationale (at least for bitcoin) behind the use of base58 is:
* Don't want 0OIl characters that look the same in some fonts and could be used to create visually identical looking account numbers. * A string with non-alphanumeric characters is not as easily accepted as an account number. * E-mail usually won't line-break if there's no punctuation to break at. * Doubleclicking selects the whole number as one word if it's all alphanumeric.
The alphabet used is: "123456789ABCDEFGHJKLMNPQRSTUVWXYZabcdefghijkmnopqrstuvwxyz"
JMN 2011-06-28 Does anyone know if there are existing Tcl implementations of base58 as used by bitcoin?