b45 0.2.3

Base45 (rfc9285) encoding and decoding for more efficient data transfer via QR codes

This repository contains b45 - a Python package and CLI for encoding/decoding data from/into Base45.

Base45 is specified in rfc9285 and it's main use case is storing arbitrary data more space-efficiently in QR codes.

So this helps when transferring snippets from/to an air-gapped computer via QR codes.

Invocation

You can directly invoke b45 from the cloned repository working directory like this:

python -m b45  -h

Alternatively, you can install the package with pip and then the b45 command line front end is installed as well.

Example:

zstd -c /bin/zstdgrep  | b45  | qrencode -t utf8

How much does it really save

In comparison to Base64 over QR code it saves up to 25 % or so.

Quick test:

{ echo '5 k'; for i in b45 base64 ; do head -c 1536 /dev/urandom | $i | qrencode -t utf8 | wc -c ; done ; echo '/ 100 * p'; } | dc

Yields for example:

75.55200

(per cent of final QR code size)

Related Work

There is also the base45 python package. Main differences:

• b45 implements encoding and decoding using Numpy vector operations and thus runs faster
• b45 supports non-standard little-endian Base45 variant
• the b45 command line front-end also supports directly reading and writing from/to files, whereas python-base45 only supports stdin and stdout

The Python bases package implements various binary-to-text encodings in a generic way, including Base45, but it doesn't come with a command line frontend.

License

This packaged is licensed under the Boost Software License Version 1 (BSL-1.0).