Base256 Encoding in Unicode (base256U)

This repository contains a C++ sample implementation to represent binary data in base256 encoding by using Unicode characters. Typical use cases are representation of safe passwords, digital keys, checksums, identifiers, hashes, extremely big numbers, or data in character-limited messengers.

What is base256U?

Each byte is represented by exactly one Unicode character (and vice versa). The mapping of byte to Unicode is dead simple:

Byte	Unicode Character	Comment
0-9	'0'-'9'	the 10 digits
10-35	'A'-'Z'	the 26 uppercase letters
36-61	'a'-'z'	the 26 lowercase letters
62-255	'À', 'Á', 'Â', 'Ã', 'Ä', ...	the 194 accent letters

✔️ Features

• Ultra compact, e.g. just 16 characters can encode 128-bit of data!
• Easy to recognize due to the accent letters.
• Safe to use: can't be remembered, so people are forced to copy & paste it (no need to hide it).
• Supports double-clicking for comfortable copy & paste (all Unicode characters are non-terminal ones).
• Supports all Unicode versions: highest code point is 387 which requires Unicode 1.0 only.
• Easy to implement: see base256U.cpp.

🎉 Examples

• 64-bit encoding: ŖÔńĪ07ėñ, or RŧáÃĆĶ2Õ
• 128-bit encoding: ĺËĀ8Ę3ĩŔá0VzœĹŀî, ŽTĭŊõł3ÐÑęGųĢÛąĶ, 5iŗ3īÛźUKĺŰÑÞbŒŜ, or ņĨqvLŀŠsůØŸÙGCŰƀ
• 256-bit encoding: ħŅŹĬšÝŋţĀĸĻňőċqâĮŹúŪßWPŞÓā8æťÁüċ, or Ě2ħŤRŧáÃĆĶ2ÕŀSŜöĄPŞÜbŰ06lŔùö9ĬŒģ

⚖️ Comparison of Encoding Standards

Base	Name	Alphabet	Example	Byte Overhead
2	Binary	0 or 1	0101101	800%
8	Octal	0-7	7734124
10	Decimal	0-9	3849834
16	Hexadecimal	0-9,a-f (case insensitive)	7a9ff34	100%
32	Base32	A-Z,2-7	S7FFQZB	60%
36	Base36	0-9,A-Z	7RT99XQ
45	Base45	0-9,A-Z,space,$,%,*,+,-,.,/,:	8X%/9:A
64	Base64	A-Z,a-z,0-9,+,-	zA8r+8q	33%/37%
85	Base85	!,",#,...,z	9jqo	25%
256	Base256U	0-9,A-Z,a-z,accent letters	ĘśŃäŞŰÀ	~75%

🔧 Installation

Execute in a terminal window: (C++ compiler and cmake required)

> git clone https://github.com/fleschutz/base256U  # or download & unzip the ZIP file (click the green button)
> cd base256U/src
> cmake .
> make
> ./base256U

The program writes a list of safe passwords (random 128 bits) in base256U encoding. Please use double-clicking and copy & paste.

🎉 Other Use-Cases

• zeichensalat: a tool to make compressed executables for copy & paste using less than 500 unicode characters. It is intended to be used on the fediverse (or in chats).

Safe Password/Key Sizes

Required is a really random password or key to rule out dictionary attacks. Attackers which try every possible key or password (called a 'brute force attack') at one billion attempts per second have to wait:

Key Size	Key Example	Max Wait Time @ 1B attempts/sec
40-bit	ŞŰÀ8Œ	about 9 minutes
56-bit	ŖÔńĪ7ėñ	about a year
128-bit	ĤŗwĹĦñŧīijēaqöĜĖŅ	about 5,783,128,169,837,158,197,871 years
256-bit	ÿőMêŽĖiĘśŃäŞŰÀ8ŒŽĎäPfSŖÔńiĪ7ėëŷò	forever

🤝 Contributing

• Contributions, suggestions, and improvements are always welcome!
• Open an Issue if you encounter bugs or have feature ideas.
• Create a Pull Request if you'd like to improve something.

📜 License & Copyright

This open source project is licensed under the CC0 license. All trademarks are the property of their respective owners.