Tamper-evident labels vs authentication tags

A tamper evident label is a seal, sticker or band on a package that shows, visibly, when the package has been opened. It is good at one question: has anyone been inside? It says nothing about whether the product was genuine in the first place. That second question is the job of an authentication tag, and brands that sell high-value or ingestible products in sealed packs often need an answer to both.

Tamper evident means that interference leaves a mark a person can see. The clearest legal definition is the US Food and Drug Administration's, in its packaging rule for over-the-counter medicines, first issued in 1982. A tamper-evident package, it says, has one or more indicators or barriers to entry which, if breached or missing, can reasonably be expected to give consumers visible evidence that tampering has occurred.^2,1

The rule covers the familiar forms: an immediate container and its closure, a carton, or a combination, all meant to give a visual indication of package integrity. It also requires the feature to stay intact through normal handling in manufacture, distribution and retail display, so that a broken seal means someone opened the pack rather than that the pack was knocked about on the way.¹

The rule goes one step further, and it is a habit any category can borrow: each retail pack must carry a statement that alerts buyers to the specific tamper-evident feature used, so that people know what an intact pack should look like.¹

Tamper seals and tamper evident stickers are the everyday versions: a label across a cap that tears when the cap turns, a band that has to be cut, a sticker over a carton flap. They are cheap, they need no device to check, and anyone can read them at a glance.

A seal proves that a package is as it was when the seal went on. It does not say who put it on. A counterfeit sealed with a convincing copy of the brand's label is, by the seal's own test, untouched. So is a genuine bottle that was emptied, refilled and resealed with a fresh label from the same printer.

The US Food and Drug Administration (FDA) rule anticipates this. It asks that the package be distinctive by design, or use a pattern, name, registered trademark, logo or picture, and it defines distinctive by design as packaging that cannot be duplicated with commonly available materials or through commonly available processes. In other words, a seal is only as good as how hard it is to copy, which is an authentication question.¹

The gap widens after the first sale. A sealed bottle of spirits or a boxed fragrance can change hands several times before anyone opens it. At each sale the seal tells the next buyer only that the pack is still closed. It cannot say where the pack came from, who sealed it, or whether the seal is one of many copies.

European medicines law draws the line explicitly. Commission Delegated Regulation (EU) 2016/161, adopted on 2 October 2015, sets out two separate safety features for the packs of certain medicines for human use. A unique identifier enables the verification of the authenticity and the identification of an individual pack. An anti-tampering device allows the verification of whether the packaging has been tampered with. The regulation has applied since 9 February 2019.³

The two features do different work. In that regulation the unique identifier is encoded in a two-dimensional barcode and checked against a repositories system, while the anti-tampering device is a physical seal. One answers "is this the genuine pack?" and the other answers "has this pack been opened?". Neither answers the other's question.³

A closure tag is an authentication tag placed across the opening, with a way to sense the opening itself. It computes a fresh authentication code each time it is tapped, like any secure tag, and adds a tamper loop: a fine detection wire, connected to the tag, that runs across the seal.

The tag has no battery, so it cannot watch the wire continuously. Instead it checks the loop each time a phone powers it. If the wire is broken, the tag records the opening in its permanent memory, and that record cannot be reset. The status travels inside the same authenticated read as the code that proves the item, so the two cannot be separated.

This changes what the seal is worth to everyone downstream. A paper seal speaks once, to whoever is holding the pack. A recorded opening can be read by every later buyer, and because the code that proves the item changes on every tap, a photo of the label or a copy of its link does not carry a closed status to a fake.

Across the opening, and nowhere else. A tag on the side of a bottle can prove the bottle; only a tag that bridges the cap and the neck can also show that the cap came off. The same rule decides placement in each category.

• Which question matters most for this product: opening, authenticity, or both? A bottle that can be refilled and resealed needs both.
• Could a counterfeiter buy or print a seal that looks like yours? If so, the seal proves little on its own.
• Who checks it? A seal is checked by eye; a tag can be checked by anyone with a phone, at any point after the factory.
• Does the seal survive normal shipping and display intact, so that a broken one means the pack was opened?
• Is the opening recorded somewhere a buyer can see, or only on the pack itself?
• Does the tag sit across the opening, where removing the cap has to break it?

The Vera Closure Tag is a Verify + Tamper tag. It bridges a lid, cap or seam, so opening the product severs the seal, and the break does not close again: a severed seal is permanent evidence the item was opened, recorded by the tag itself. Every tap also computes a fresh encrypted code, so the bottle or the case proves its identity as well as carrying its seal, and a forwarded link or a screenshot opens its certificate without the verified state.

A tap shows whether the closure was opened. The tag carries the item's identity from the factory, so the same certificate follows the bottle from the cellar or the production line through every owner after.