Draw an ASCII-Art representing the fingerprint so human brain can
profit from its built-in pattern recognition ability.
This technique is called "random art" and can be found in some
scientific publications like this original paper:
"Hash Visualization: a New Technique to improve Real-World Security",
Perrig A. and Song D., 1999, International Workshop on Cryptographic
Techniques and E-Commerce (CrypTEC '99)
The subject came up in a talk by Dan Kaminsky, too.
If you see the picture is different, the key is different.
If the picture looks the same, you still know nothing.
The algorithm used here is a worm crawling over a discrete plane,
leaving a trace (augmenting the field) everywhere it goes.
Movement is taken from dgst_raw 2bit-wise. Bumping into walls
makes the respective movement vector be ignored for this turn.
Graphs are not unambiguous, because circles in graphs can be
walked in either direction.