Validus: a high-throughput, yet beefy 192-bit OWHF written in (reasonably) portable C11/17.
Intro
I know the world doesn't need another hash function; I began this project 19 years ago. Things were different then: CPUs were not even a hundredth of what they are now; ditto for disk and memory I/O. I had an idea after looking at the source code for Ronald Rivest's MD5 algorithm which is of course world-famous (and no longer used in any serious capacity due to security concerns/collisions/rainbow tables). Between us, I approached him with my idea, and he brushed me aside and said he's already working on something similar for "MD6." I'll let history speak for itself there.
TLDR
After researching and reading through every hash function's source code I could find, I thought that the fundamental way hash functions were structured at the time could be improved upon–specifically by processing larger blocks of input data in one go (192-bit seemed to be the sweet spot–it could be 512 or 1024 by now 🙃), equating to less time spent doing things other than computing the hash–such as, but not limited to: waiting on I/O, copying buffers around, pushing and popping args on and off the stack, etc.
Validus was born from the aforementioned concept, and I believe it to be a success in that regard. I no longer have access to the test and timing rigs that I built to prove it, but it is considerably faster than any other hash producing a 192-bit fingerprint that I am aware of. In fact, it's within ~1% of FNV-1a @ 64-bit the last time I checked, which is essentially a 10 LOC algorithm (Validus is hundreds of LOC).
Disclaimer
I am not making any claims about cryptographic security in Validus (I am not a cryptologist), nor do I guarantee it not vulnurable to collisions, but it does pass the Avalanche Criterion (1 bit of input changes = 50% of output bits change).
Validus is now in the public domain because it's a waste to leave it sitting in a private repository. It's been cleaned up a bit, and there's a CLI interface to hash files and strings and such.
All questions, comments, and criticisms are welcome–especially if you find a bug, typo, or flaw (or you use it in a cool project–I'd love to have a list here of projects utilizing it).
Building from source
CMake: there's a presets file, and Ninja is set as the default build tool. If you have VS Code, you just need the CMake tools extension and you can build and run with a few keystrokes. Without VS Code (or experience with CMake), as long as you have a reasonably recent version of CMake, the following should do the trick: cmake --preset release && cmake --build build.
Build products
Upon a successful build, the following are created[^1]:
build/validus: CLI applicationbuild/libvalidus.a: Static librarybuild/libvalidus.so: Shared library
[^1]: The exact filenames and extensions are platform-dependent. For example, on Windows, you will get validus.exe, validus_static.lib and validus_shared.dll.
CLI interface
Once CMake finishes building, the CLI app will be located at build/validus. The following is a breakdown of its basic usage:
Most of these are self-explanatory. The -t option causes the algorithm to hash a known set of strings, with a predefined known correct output. If the output is green, Validus is working correctly; if it's red, something has gone wrong during compilation and it is probably a bug. Please file an issue if you encounter this situtation!
Full Documentation
Thanks to Doxygen, Validus has a dedicated documentation site.
Releases
Some tweaks to the build configuration need to take place, but sooner rather than later, static/shared libraries and the CLI app will be packaged (at least for macOS, Windows and Linux on x86_64 & aarch64). In the mean time, building with CMake will have to do.
Latin
If you read this far, you might as well know that Validus means "strong, robust, able" in Latin. Hopefully someone doesn't break it the first week it's on GitHub.
