A script to present BLAKE2b hashes as small ASCII-art pictures, similarly to OpenSSH's randomart.
This allows easier verification by humans but may not be as secure as a bytewise comparison of the digest!
See the paper Hash Visualization: a New Technique to improve Real-World Security for more information on the concept of random art.
The paper The drunken bishop: An analysis of the OpenSSH fingerprint visualization algorithm analyses the OpenSSH implementation in more detail.
Just to be clear: the input is passed into a hash function and its output is then used to generate the ASCII art. By virtue of BLAKE2b being a cryptographically secure hash function, any change in input will lead to a radically different output.
It should also be explicitly noted that my algorithm is similar but not identical to the "drunken bishop" walk of the OpenSSH implementation. The implementation at hand:
- flips sides at the borders, which turns the field into a torus
- moves in all possible directions with distance 1, not only diagonally
- does not mark start (
S) and end (E) and uses a different character palette
I have not performed any similar analysis[2][^2] but would expect my implementation to perform no worse.
Install the latest version with pip directly from GitHub:
pip install git+https://github.com/ansemjo/randomart
Or from PyPI:
pip install randomart
The script expects a file in the first positional argument or otherwise simply reads from standard input. It is thus best suitable for usage in a pipe:
echo 'Hello, World!' | randomart.py
There are two flags to control the output:
--asciiuse only ASCII characters for the box frame--hash- print the computed digest before the randomart picture
Otherwise use randomart.py --help for usage help.
If you want to use your own hash you can import from random_art.randomart:
from random_art.randomart import draw, drunkenwalk
...
# generate your hash digest
digest = ...
# generate randomart, HASHNAME must be 10 characters
art = draw(drunkenwalk(digest), HASHNAME)
print(art)