visprint

fractal fingerprint generator.

News

[7-2-2007]
Visprint release 2.1 is now available for download with several enhancements.

This version features several bugfixes, a new color pattern and the option of using different hash functions as input (the checksum length is no longer limited to 32 characters).

Special thanks to Jan Merka for all the feedback that led to this version.

[11-12-2006]
Visprint is being used in NASA's Virtual Magnetospheric Observatory website!!

Jan Merka, a researcher at VMO, has included visprint as eye-candy for the data query interface in NASA's VMO website.

Overview

Visprint makes cool fractal fingerprint png images based on the contents of any file. The image will be different for almost every file with even slightly different contents. Visprint uses the IFS fractal generation process, pioneered by Michael Barnsley. It is a way to create images which are self-similar to infinite depths. In other words, the picture is made up of smaller versions of itself.

So... What about security?

Visprint is just a "toy" program that generates cool graphics. The purpose is to serve as a fun graphic complement to checksums. In no way whatsoever should it be used as a stand-alone security tool. It's not intended to be a substitute for any file checker. Even though it can be used to check differences in files and it uses cryptographic hash functions (md5, sha1, sha256...) as it's input, it has not been designed nor tested with heavy security use in mind.

License

visprint is "free" software released under the GNU General Public License (GPL).

Developer

Goiz "Samhain" Ruiz de Gopegui
GPG Public Key: samhain.asc

A note on the history of visprint code

The original visprint code was written by Ian Goldberg, based on an idea by Hal Finney, in a post to the coderpunks mailing list. The most excellent color enhancements were added by Raph Levien. David Johnston made a port for Win95 console mode and added a bunch of nice features. Soren Andersen developed the png and transparency code.

I decided to rescue the orphaned code from oblivion, clean it up, document it and maintain it. As far as I know, there is no copyright infringement. The code has always been freely available in the net and the previous authors are properly acknowledged. (Please, don't sue me ;)

Download

The current version of visprint is 2.1

Source Code: visprint-2.1.tar.gz
gpg signature: visprint-2.1.asc
md5 checksum: visprint-2.1.md5
visprint sha1 image: visprint21sha1.png

Slackware 11.0 binary package: visprint-2.1-i686-smhn.tgz
gpg signature: visprint-2.1slack.asc
md5 checksum: visprint-2.1slack.md5
visprint sha1 image: visprint21slacksha1.png

Old versions can be reached here.

Changelog


v2.1 (28 november 2006):
~~~~~~~~~~~~~~~~~~~~~~~~~
 	- Added the option of using different hash functions as input (-l switch)
	- Added the option of using an alternate color scheme by flipping RGB to BGR (-c switch)
	- Polished and fixed the grayscale color scheme.
	- Renamed the previous -c switch to -a (Area coloring scheme).
	- Fixed a bug in the transparency code.
	- Updated the man page and the help screen.
	- Some minor bugfixes and code cleanups.

Thanks to Jan Merka for the feedback on this version.

More information in the full changelog

Screenshots


md5, no options	md5, white background

md5, transparent on black bg	md5, 4 area coloring

sha1, semi-grayscale with -b70 background value	sha1, alternate coloring