Practical implementation of a methodology for digital images authentication using forensics techniques

This work presents a forensics analysis methodology implemented to detect modifications in JPEG digital images by analyzing the image’s metadata, thumbnail, camera traces and compression signatures. Best practices related with digital evidence and forensics analysis are considered to determine if the technical attributes and the qualities of an image are consistent with each other. This methodology is defined according to the recommendations of the Good Practice Guide for Computer-Based Electronic Evidence defined by Association of Chief Police Officers of UK; the methodology certainty level is verified by an efficiency coefficient, calculated by the quotient of the number of correct resolutions and the total number of analyzed images. This methodology can help to determine if a specific digital image can be used as evidence, and thereby, help to clarify events or incidents with legal, civil, administrative or criminal implications. Another advantage of the methodology is that it can be applied with open source software tools.