GOST CryptoPro Hash Code Calculator

The GOST hash function refers to a family of cryptographic hash functions defined by the Russian government. The most well-known version is GOST R 34.11-94, which was widely used in Russia and other countries that adopted GOST standards. It was later succeeded by GOST R 34.11-2012, also known as Streebog. This is the original version, modified to use S-boxes from the CryptoPro suite instead of the original "test parameters" S-boxes.

Full disclosure: I did not write the specific implementation of the hash function used on this page. It is a standard function included with the PHP programming language. I only made the web interface to make it publicly available here for convenience.

About the GOST CryptoPro Hash Algorithm

I'm neither a mathematician nor a cryptographer, but I'll try to explain this hash function using an everyday analogy that other non-mathematicians can hopefully understand. If you prefer the scientifically correct, math-heavy version, I'm sure you can find that elsewhere ;-)

Think of GOST like an advanced "data blender" that turns anything you put into it into a unique smoothie. Given the same ingredients, it will always make the same smoothie, but if even a tiny change is made to the ingredients, you will get a completely different smoothie.

This is a three step process:

Step 1: Preparing the Ingredients (Padding)

• You start with your "ingredients" (the message).
• If your message isn't the right size for the blender, GOST adds some "filler" (extra data) to make it fit perfectly. This is like adding water to fill up the blender.

Step 2: Blending with Secret Recipes (Mixing)

• GOST doesn’t just blend once - it mixes the data over and over again using a secret recipe.
• This recipe involves:
  • Chopping (breaking the data into small parts).
  • Swapping (shuffling the parts around).
  • Stirring (mixing them back together in new ways).

Imagine a chef who has a complex way of mixing ingredients to make sure no one can guess how it's done. That’s what GOST does with your data.

Step 3: Serving the Smoothie (Final Hash)

• After all the mixing, you get your smoothie - a fixed-size, scrambled version of your data.
• This smoothie is unique to your original ingredients. Change anything, even a tiny crumb, and you'll get a completely different smoothie.

This version of the GOST function uses the CryptoPro S-boxes, which is recommended. If you for some reason need a version that uses the original "test parameters" S-boxes, you can find it here: GOST Hash Code Calculator