Base64

base64 is a data encoding scheme whereby binary-encoded data is converted to printable ASCII characters. The only characters used are the upper- and lower-case Roman alphabet characters (A-Z, a-z), the numerals (0-9), and the "+" and "/" symbols, with the "=" symbol as a special suffix code. Full specifications for base64 are contained in RFC 1421 and RFC 2440. The scheme is defined only for data whose original length is a multiple of 8 bits, a requirement met by most computer file formats. The resultant base64-encoded data has a length that is approximately 33% greater than the original data, and typically appears as seemingly random characters.

For example, the Wikipedia slogan,

"Man is distinguished, not only by his reason, but by this singular passion from other animals, which is a lust of the mind, that by a perseverance of delight in the continued and indefatigable generation of knowledge, exceeds the short vehemence of any carnal pleasure."

encoded in base64 is as follows:

TWFuIGlzIGRpc3Rpbmd1aXNoZWQsIG5vdCBvbmx5IGJ5IGhpcyByZWFzb24sIGJ1dCBieSB0
aGlzIHNpbmd1bGFyIHBhc3Npb24gZnJvbSBvdGhlciBhbmltYWxzLCB3aGljaCBpcyBhIGx1
c3Qgb2YgdGhlIG1pbmQsIHRoYXQgYnkgYSBwZXJzZXZlcmFuY2Ugb2YgZGVsaWdodCBpbiB0
aGUgY29udGludWVkIGFuZCBpbmRlZmF0aWdhYmxlIGdlbmVyYXRpb24gb2Yga25vd2xlZGdl
LCBleGNlZWRzIHRoZSBzaG9ydCB2ZWhlbWVuY2Ugb2YgYW55IGNhcm5hbCBwbGVhc3VyZS4=

See also: Radix-64, ASCII Armor

External Links

• ''OpenPGP Message Format"", RFC 2440, http://www.faqs.org/rfcs/rfc2440.html
• Source code for the base64 algorithm, for use in translating files to and from base64 encoding is located at http://base64.sourceforge.net