Monthly Archives: November 2017

Proving a negative

I have a dear old friend who is a brilliant photographer and artist. Years ago, when he was teaching at the Art Center College of Design in Pasadena, CA, he would occasionally ask me to substitute for him in class as he travelled the world to take photos. He would introduce me to the class as the person at the LAPD who authenticates digital media – the guy who inspects images for evidence of Photoshopping. Then, he’d say something to the effect that I would be judging their composites, so they’d better be good enough to fool me.

Last year, I wrote a bit about my experiences authenticating files for the City / County of Los Angeles. Today, I want to address a common misconception about authentication – proving a negative.

So many requests for authentication begin with the statement, “tell me if it’s been Photoshopped.” This request for a “blind authentication” asks the analyst to prove a negative. It’s a very tough request to fulfill.

In general, this could be obtained with a certain degree of certainty if the image is verified to be an original from a certain device, with no signs of recapture and, possibly verifying the consistency on the sensor noise pattern (PRNU).

However, it is very common nowadays to work on images that are not originals but have been shared on the web or through social media, usually multiple consecutive times. This implies that metadata and other information about the format are gone, and usually the traces of tampering – if any – have been covered by multiple steps of compression and resizing. So you know easily that the picture is not an original, but it’s very difficult to rely on pixel statistics to evaluate possible tampering at the visual level.

Here’s what the US evidence codes say about authentication (there are variations in other countries, but the basic concept holds):

  • It starts with the person submitting the item. They (attorney, witness, etc.) swear / affirm that the image accurately depicts what it’s supposed to depict – that it’s a contextually accurate representation of what’s at issue.
  • This process of swearing / affirming comes with a bit of jeopardy. One swears “under penalty of perjury.” Thus, the burden is on the person submitting the item to be absolutely sure the item is contextually accurate and not “Photoshopped” to change the context. If they’re proven to have committed perjury, there’s fines / fees and potentially jail time involved.
  • The person submits the file to support a claim. They swear / affirm, under penalty of perjury, that the file is authentic and accurately depicts the context of the claim.

Then, someone else cries foul. Someone else claims that the file has been altered in a specific way – item(s) deleted / added – scene cropped – etc.

It’s this specific allegation of forgery that is needed to test the claims. If there is no specific claim, then one is engaged in a “blind” authentication (attempting to prove a negative). Continue reading

Amped and Griffeye together at Milipol Paris

This year, we will attend Milipol Paris together with our integration partner, Griffeye.

Come visit the Amped and Griffeye team in Hall 6, Aisle A, Booth 148 (it’s a big event!) to see for yourself how the integrated solutions work.

More about the partnership

Griffeye’s Analyze DI and Analyze CS can be used to handle large volumes of images and videos, filter irrelevant digital files, prioritise, correlate and identify the most pertinent material in investigations. Amped FIVE, Amped Authenticate and Amped DVRConv enable in-depth analysis of images and videos, convert unplayable videos to standard formats, detect tampering of material, and enhance quality of video files to provide an overview of any content requiring further analysis. Using an open API, images and videos can now be passed between Griffeye and Amped, removing the labour intensive process of bringing evidence separately into each application.

More about Milipol Paris

Milipol Paris, the leading event for homeland security is organized under the patronage of the French Ministry of Interior. It is an official event carried out in partnership with the French National Police and Gendarmerie, Civil Defence Service, French Customs, City Police, Interpol, etc.

Sectors in Milipol Paris

Data protection – Information and Communication systems / Economic and Industrial Intelligence / Systems integration / Risk analysis and management / CBRN / Civil Defence / Forensic science services / Law enforcement / Anti-terrorism – Special Forces / Protection of industrial and sensitive sites / Fight against organised crime / Security of public places – Urban Security / Transport security / Port and airport security – Border control / Road safety / Security of financial systems / Prison sector / Oil and gas sector

Fore more information: https://en.milipol.com/

The Importance of Using Images as Evidence

How many cases have you worked on lately that involved video footage or a photo as evidence? Are you really sure everything possible has been done regarding the proper use of those images for investigations and if they have been exploited to their full potential? Are you really sure that images and videos have been properly validated and are not the result of some tampering? Was the image of sufficient quality to prove or disprove some testimony? Has the image and video been analyzed by an expert with the proper tools?

These, and many more, are the question we will try to answer in our monthly column in the Lawyer Monthly magazine.

There’s a lot to know and to discuss, and in this brief overview we don’t expect you to become an expert, but at least we hope to point you in the right direction for further study.

Read the first issue:  The Importance of Using Images as Evidence

Come visit us in Abu Dhabi at the GCC Forensic Science Conference

In partnership with the Abu Dhabi police, the GCC Forensic Science Conference and Exhibition, taking place 14-16 November at the Fairmont Bab Al Bahr Abu Dhabi, will showcase the latest equipment and services as well as provide education, best practices, training and networking.

The GCC Forensic Science Conference aims to focus on the entire investigation journey, from the crime scene to the courtroom. The event offers a unique 360 view of the forensics industry, including lab equipment, crime scene, digital investigation, and forensic pathology.

In addition to the conference, a small exhibition will feature suppliers offering market-leading products to the entire forensics industry.

Come visit the Amped Software team at booth #9 for your personal demo of our leading image and video forensic products.

Find out more

Exposing fraudulent digital images

As a predominantly visual species, we tend to believe what we see. Throughout human evolution, our primary sense of sight has allowed us to analyse primeval threats. We are genetically hardwired to process and trust what our eyes tell us.

This innate hardwiring means that the arrival of digital images has posed a problem for the fraud investigation community. There are many different reasons why someone would want to
maliciously alter a photo to ‘tell a different story’. Although photos can be manipulated with ease, many people still harbour a natural tendency to trust photos as a true and accurate representation of the scene in front of us.

The article published in Computer Fraud & Security describes how images may be altered and the techniques and processes we can use to spot photos that have been modified. With the right tools and training, exposing doctored images in fraud investigations is now not only financially and technically viable, but urgently necessary.

Read the full article here