netMIH 0.5.0

.NET Core 2.2 This package targets .NET Core 2.2. The package is compatible with this framework or higher.
There is a newer prerelease version of this package available.
See the version list below for details. 
dotnet add package netMIH --version 0.5.0
                    


                    

                
NuGet\Install-Package netMIH -Version 0.5.0
This command is intended to be used within the Package Manager Console in Visual Studio, as it uses the NuGet module's version of Install-Package. 
<PackageReference Include="netMIH" Version="0.5.0" />
For projects that support PackageReference, copy this XML node into the project file to reference the package. 
<PackageVersion Include="netMIH" Version="0.5.0" />
                    


                            Directory.Packages.props
                        

                    

                
<PackageReference Include="netMIH" />
                    


                            Project file
For projects that support Central Package Management (CPM), copy this XML node into the solution Directory.Packages.props file to version the package. 
paket add netMIH --version 0.5.0
                    


                    

                
#r "nuget: netMIH, 0.5.0"
#r directive can be used in F# Interactive and Polyglot Notebooks. Copy this into the interactive tool or source code of the script to reference the package. 
#:package netMIH@0.5.0
#:package directive can be used in C# file-based apps starting in .NET 10 preview 4. Copy this into a .cs file before any lines of code to reference the package. 
#addin nuget:?package=netMIH&version=0.5.0
                    


                            Install as a Cake Addin
                        

                    

                
#tool nuget:?package=netMIH&version=0.5.0
                    


                            Install as a Cake Tool

netMIH

A .NET implementation of multiple index hashing by Norouzi et al, based on a description in the threatexchange repository

Description

Multiple Index Hashing (MIH) is a relatively lightweight means for accelerating lookups for fuzzy hashes (e.g. PhotoDNA and PDQ) within a pre-defined hamming distance. Instead of a linear search through every record, multiple indices are made for separate windows/slots within each hash. The threatexchange document (linked above) provides a good, 'plain English' description for those who (like me) struggle with mathematical terminology and notation.

Installation

Available on NuGet

Install-Package netMIH

Usage

The constructor can be used for custom implementations of match thresholds, window sizes etc, but otherwise, for PDQ, Default values for MIHIndex constructor and train() method are set for PDQ hash, using 32 bit match threshold (30 being non divisible by 8).

using netMIH

// Uses pre-configured values for PDQ hash
var index = new Index(Index.Configuration.PDQ);
var hashes = new string[] {"358c86641a5269ab5b0db5f1b2315c1642cef9652c39b6ced9f646d91f071927"};

//add entries to the index
index.Update(hashes, "ignorable");

// TRAIN the index - YOU NEED TO DO THIS BEFORE QUERYING!
index.train()

//query index for identical hashes
var results = index.Query("fc4d8e2130177f8f6ce2a03bd27fa8e6b1067a1ac8f0068037215df6491eee1f", 0);

//query index for entries with hamming distance of 1 or less
var results = index.Query("fc4d8e2130177f8f6ce2a03bd27fa8e6b1067a1ac8f0068037215df6491eee1f", 1);

// query index for entries with hamming distance of 34
// this is bigger than default match threshold of 32 for PDQ, so will utilise linear lookup. 
// This will be slower than MIH and performance will get worse the bigger the dataset gets 
var results = index.Query("fc4d8e2130177f8f6ce2a03bd27fa8e6b1067a1ac8f0068037215df6491eee1f", 34);

Licensing

This is released under an MIT licence.

Product Compatible and additional computed target framework versions.
.NET net5.0 was computed.  net5.0-windows was computed.  net6.0 was computed.  net6.0-android was computed.  net6.0-ios was computed.  net6.0-maccatalyst was computed.  net6.0-macos was computed.  net6.0-tvos was computed.  net6.0-windows was computed.  net7.0 was computed.  net7.0-android was computed.  net7.0-ios was computed.  net7.0-maccatalyst was computed.  net7.0-macos was computed.  net7.0-tvos was computed.  net7.0-windows was computed.  net8.0 was computed.  net8.0-android was computed.  net8.0-browser was computed.  net8.0-ios was computed.  net8.0-maccatalyst was computed.  net8.0-macos was computed.  net8.0-tvos was computed.  net8.0-windows was computed.  net9.0 was computed.  net9.0-android was computed.  net9.0-browser was computed.  net9.0-ios was computed.  net9.0-maccatalyst was computed.  net9.0-macos was computed.  net9.0-tvos was computed.  net9.0-windows was computed.  net10.0 was computed.  net10.0-android was computed.  net10.0-browser was computed.  net10.0-ios was computed.  net10.0-maccatalyst was computed.  net10.0-macos was computed.  net10.0-tvos was computed.  net10.0-windows was computed. 
.NET Core netcoreapp2.2 is compatible.  netcoreapp3.0 was computed.  netcoreapp3.1 was computed. 
Compatible target framework(s)
Included target framework(s) (in package)
Learn more about Target Frameworks and .NET Standard.

  • .NETCoreApp 2.2

    • No dependencies.

NuGet packages

This package is not used by any NuGet packages.

GitHub repositories

This package is not used by any popular GitHub repositories.

Version Downloads Last Updated
1.0.0-beta 493 9/26/2019
0.5.0 679 9/26/2019
0.4.0 574 9/26/2019
0.3.0 612 9/14/2019
0.2.0 612 9/12/2019
0.1.0 588 9/10/2019