Moved to



Project Description
Library for calculating context triggered piecewise hashes (CTPH) also called fuzzy hashes.

Fuzzy hashes can be used to match data that have similarities, such as two sets of data with sequences of identical bytes in the same order, although bytes in between these sequences may be different in both content and length.

More information about CTPH: Identifying almost identical files using context triggered piecewise hashes


A pure .NET managed version of the fuzzy hashing algorithm used in the program ssdeep which is based on the spam-email detector SpamSum originally developed by Dr. Andrew Trigdell .

Example of use:

using System;
using Hyldahl.Hashing.SpamSum;

namespace Hyldahl.Hashing.Test
    class SpamSumTest
        public void Test()
            SpamSumSignature signature = FuzzyHashing.Calculate(@"c:\myfile.txt");

            SpamSumSignature signatureToCompare = new SpamSumSignature("768:asdfmAAjaHx/4DpIXYSEAdP0Pn0nxqgeFjviVHeFc:asdftSin0nrelviNeK");

            int result = FuzzyHashing.Compare(signature, signatureToCompare);

            Console.WriteLine("signature:          " + signature);
            Console.WriteLine("signatureToCompare: " + signatureToCompare);
            Console.WriteLine("Similarity:         " + result);


signature:          768:ZoLymAAjaHx/4DpIXYSEAdP0Pn0nxqgeFjviVHeFc:KCHOtSin0nrelviNeK
signatureToCompare: 768:asdfmAAjaHx/4DpIXYSEAdP0Pn0nxqgeFjviVHeFc:asdftSin0nrelviNeK
Similarity:         99



Last edited Apr 2, 2015 at 10:49 AM by Hyldahl, version 7