Base64 - text format of binary data
is an encoding system that converts binary data to a text string, which contains only the basic ASCII
It is used, for example, in the MIME
extension for transmission e-mails in the original 7-bit mail system on the Internet.
It is defined in RFC 4648
always encodes three octets of binary data using four ASCII
The encoding uses a 64-element character set consisting of upper and lower case letters of the English alphabet, digits and plus ('+') and slash ('/') characters.
If the number of octets of the original data is not divisible by three, then adds one or two equals signs ('=') to the end of the encoded text.
- The length of the resulting string is usually increased by 33%.
The usage in the PROMOTIC system:
- The Base64
encoding is shorter than the HexaString
encoding, which uses only 0-9, A-F
characters for encoding and which increases the length by 50%.