In storage and/or transport of certain items, the ability to detect tampering with a container or compartment for such items can be necessary and valuable. In the transport of hazardous substances or nuclear materials (including fuels and/or radioactive waste), there are particularly stringent requirements to ensure integrity as well as safe transport and storage of materials. A retailer shipping inventory may need to know whether tampering with the container has occurred during transport to determine if shipment is original and complete.

Original bolt (left), and the bolt after tampering.

Typically, a container is closed with bolts and then sealed. The seal is a separate item that must be removed to allow the container to be opened. The process of removing the seal causes an irreversible change. If someone tries to secretly gain access to the contents, even if they reclose the container, the seal would indicate that it was tampered with. Seals have a unique serial number on them so they cannot easily be replaced to hide access. This invention eliminates the separate seal by using a unique microstructure of one or more closure bolts. A bolt is already used to close the container.

All metal items are unique at the microscopic level. They are made up of individual grains arranged in a unique pattern, much like a snowball is made up of individual snowflakes. Thanks to modern megapixel cameras, this unique grain structure can be photographed. When the container is being inspected for tampering, another photograph is taken. These are compared, and any changes in the grain structure indicate tampering. Even if the bolt is removed and reinstalled, the deformation of the grain structure will be unique.

Applications for this technology are as diverse as securing nuclear materials for non-proliferation, and securing of cargo being shipped cross-country or overseas. To secure cargo, the bolt could be inserted into the hasp on the container doors. When the recipient receives their cargo, they can photograph the bolt and compare it to an image taken at the point of origin. If the bolt shows signs of tampering, the cargo could be rejected or subject to closer inspection.

For more information, contact Dale Haas at This email address is being protected from spambots. You need JavaScript enabled to view it.; 803-725-4185.

Tech Briefs Magazine

This article first appeared in the September, 2017 issue of Tech Briefs Magazine.

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