To get straight to the point - walkthrough metal detectors are a security technology to attempt to detect and thus remove weapons and dangerous items from individuals to make a safe space. What if they were much more fallible than expected?
I'm not here to fear-monger either - these problems are preventable with proper use and changed in guidelines. Like many security controls, their exploitation is commonly due to those who implement and monitor them. However, in order to create these changes, more proof-of-concepts and solutions need to be tested. We already have a few to start.
The walkthrough metal detector (WTMD) research was not my original idea. It started out of research projects from PHSI and another Garrett 6500i was donated to our lab. This machine was not ours and we did not have permission to modify or conduct digital attacks on the detector. We were supposed to use physical modifications to hide or modify the results of the screening.
One colleague in particular Pat Glass created a wooden rig that would allow student researchers to test passing items through the detector consistently and accurately. PHSI students tested common suggestions and ideas on getting pass the detector. They tried wrapping items in Mylar, changing the item's surface area, and other tricks to get the metal detector to create a false negative. More information about that research can be watched in my GrrCon talk. Thank you to the researcher who named that metal detector Mr. Den City - Katie.
So here's the general plan for evaluating this technology:
- Test materials on person to create false negative ✓
- Change properties on items passing through to create false negative ✓
- Attempt to incorrectly screen resulting in false negatives ✓
- Attempt to incorrect screen resulting in a false positives ?
- Audit common guidelines expected results to tested outcomes ✓
- When venues set their WTMD levels, are the capturing the results they are expecting?
- spoiler: not really.
- Attempt material changes resulting in false positive
- Re-evaluate original threatening materials versus newer threatening materials and access proper WTMD levels
- What levels should they be in order to detect what we originally thought was dangerous, and what we now evaluate to be dangerous in 2020?
I'm obligated in the interest of PHSI to redact a few details.
- Re-test and document the previous work and complete the in-progress work
- Access other avenues of intentional false positives
- Get a second WTMD 6500i
- Install the module typically in use at venues and security checkpoints which utilize multiple WTMDs together.
- Access the vulnerabilities associated with multiple WTMD use.
- This does not refer to the human error associated with Lane Consistency that I wrote about in my thesis. This is a technology centered inquiry.
Someone once told me that your Master's thesis will be your worst work, and goodness is that the case for me. When I get my first prof appointment I'll re-work and update it. Anyway...
- A couple of surprises
- hint: there's a local area network here
I hope this has answered a couple questions or at least has a few people interested in the project! I'll do my best to share updates as they come up there.