Tamper-evident tag
Specialty tags
What is it?
A tamper-evident RFID tag is designed to be destroyed if someone tries to remove or transfer it. The antenna is deliberately fragile – printed with thin conductive traces that break when the label is peeled, tearing the antenna circuit and rendering the tag unreadable. Some designs use a "void" pattern that appears when removed, providing visual evidence alongside the electronic evidence.
How it works
The antenna traces are routed across a score line or weak point in the label. Peeling the label breaks the antenna, which changes or kills the RF response. NFC variants (like NXP NTAG 424 DNA TagTamper) have a dedicated tamper detection loop – a separate conductive trace that the chip monitors. When the loop breaks, the chip records the tamper event and changes its cryptographic output on next tap.
Use cases
- Pharmaceutical serialisation and anti-counterfeiting
- Wine and spirits authentication
- Warranty seal verification
- Document and evidence bags
- Luxury goods provenance
- Electronics warranty tags
Pros
- Provides both electronic and visual tamper evidence
- NFC variants allow consumers to verify authenticity with a phone
- Works with standard RFID infrastructure
- Cryptographic variants are extremely difficult to clone
Cons
- Single use – cannot be re-applied
- More expensive than standard labels
- False positives if tag is accidentally damaged
- Requires backend system to track tamper status
Specifications
| Power type | Passive – powered by reader signal |
|---|---|
| Frequency | UHF (860–960 MHz) or HF/NFC (13.56 MHz) |
| Read range | UHF: 2–8 m; NFC: up to 5 cm |
| Lifespan | Single use |
| Price range | $0.15–$1.00 per unit |
| Environmental rating | Indoor; controlled environments |