Tamper-evident technology

Tamper-evident describes a device or process that makes unauthorized access to the protected object easily detected.

Technicians at the National Security Agency developed anti-tamper holograph and prism labels that are difficult to duplicate.

The amount of stock which needed to be destroyed (because it was impossible to tell if a given item had been tampered with), and the threat of public fear, meant that tamper-evident design principles had the potential to save a lot of money in the future.

Newer jars of food tend to come with a plastic wrap around the edge of the lid, which is removed when opening, although the springy-cap designs are still in common use.

Tamper-evident packaging also extends to protect stores; there are some scale labels for meats and deli products that will tear if removed.

Due to FDA regulations, many manufacturers of food and medicine (as well as other products) now use induction sealing and other special means to help provide evidence of tampering.

The still ongoing (as of 2025[update]) opioid abuse epidemic has led to a search for tamper-evident strategies to protect central vascular lines.

Intravenous drug users often acquire infections of the heart valves (endocarditis), liver, bones, lungs, and other organs.

In financial terms, tamper-evident design overlaps a lot with anti-forgery techniques, as ways to detect monetary tokens which are not what they seem.

However, this can easily be defeated by warming up the label using a blow dryer or heat gun, so it will be more flexible and forgiving to removal (and reapplication).

This makes it difficult to move a vignette from one car to another, or to peel off a price tag from a cheaper article and reapply it to a more expensive one.

In police work, tamper-evident techniques must often be used to guard access to evidence, providing means of storing items and samples in a way which can be used to prove that they were not altered after their collection.

Security seals are commonly employed on devices such as electronic voting machines in an attempt to detect tampering.

However, testing by Argonne National Laboratory and others demonstrates that some existing seals can be quickly defeated by a trained person using low-tech methods.