Using OSForensics with PhotoDNA

What is PhotoNDA?

PhotoDNA is a proprietary image hashing and identification technology developed by Microsoft. It is intended to provide a unique identifier for individual images for use in automatic detection of illicit material.

PhotoDNA differs from traditional hash based solutions and was developed specifically for the identification of images. Traditional file hashing identification relies on the underlying binary data of the file remaining perfectly consistent in order to reproduce the original hash value. Image files however are often subject to variations of their underlying binary data, this can be caused by file format changes, modifications to meta-data or deliberate alterations to the image.

To combat this, PhotoDNA utilizes image recognition technology in order to generate unique hashes separate from the underlying file data. This technique ensures that the same hash can be calculated even if the image has been re-sized, compressed, re-exported, deliberately altered or had meta data changed or removed or modified.

Who can use PhotoDNA?

Use of the PhotoDNA API for the generation of image hashes is currently limited to qualified organizations and is subject to licensing on an organization by organization basis. For this reason, PhotoDNA functionality is not included in the base install of OSForensics and access to the functionality must be requested in order to use. More information about PhotoDNA and becoming a qualified organization can be found on the Microsoft Website.

How do I install PhotoDNA for use with OSForensics?

Once granted access to PhotoDNA, the relevant files needed to enable its functionality can be downloaded from the Passmark software management page. Official copies of PhotoDNA not provided by Passmark can also be used if the minimum version requirements are met. The contents of the folder should be unzipped and placed in a folder titled "PhotoDNA" in the root install directory of the OSForensics application. The functionality should now be enabled for all modules throughout OSForensics.

Supported Versions

PhotoDNA is available only in OSForensics V11.0.1000 and up and currently supports the following PhotoDNA versions:

• PhotoDNA Version 1.05.20160330
• PhotoDNA Version 1.72.20170329

How do I get qualify for access?

To gain access, please email support@passmark.com with the following details:

• Name
• Organization