Originality Signature

What Is an Originality Signature?

An originality signatureoriginality signatureECC digital signature proving chip authenticity (NXP)View full → is a factory-programmed Elliptic Curve Cryptography (ECC) digital signature embedded in NFC chips by the manufacturer — most commonly NXP Semiconductors. The signature mathematically proves that a specific chip was produced on a genuine NXP production line. Because the private signing key never leaves NXP's secure manufacturing facility, the signature cannot be forged even by an attacker with full physical access to the chip.

How It Works

During manufacturing, NXP computes an ECDSA signature over the chip's UID using a private key held within their Hardware Security Module (HSM) infrastructure. The resulting signature (typically 32 or 64 bytes) is stored in a read-only area of the chip's memory.

To verify authenticity:

1. Read the chip's UID and originality signature via a standard NFC command.
2. Retrieve NXP's corresponding public key (published in documentation).
3. Perform ECDSA verification using the public key, UID, and signature.

If verification succeeds, the chip is confirmed genuine. If it fails, the chip is counterfeit or tampered.

Supported Chips

Originality signatures are available on most modern NXP chip families: NTAG 21x (213, 215, 216), NTAG 424 DNA / DNA TagTamper, NTAG I2C Plus, MIFARE Ultralight EV1, and ICODE SLIX2 / DNA.

Limitations

While originality signatures confirm the chip is genuine, they do not prevent all attack vectors:

• Data cloning to a genuine chip: An attacker could buy genuine NXP chips and copy NDEF data from a legitimate tag. The clone passes the originality check because the chip itself is genuine. Mitigation requires combining originality with SUN/SDM dynamic authenticationauthenticationIdentity verification of NFC tags/readers via passwords or cryptographyView full →.
• No data protection: Originality signatures do not encrypt or restrict access to the tag's user memory. Use password protection or AES encryption for data confidentiality.

Best Practice

For robust anti-cloning in brand protection and product authentication, combine the originality signature with SDM. The originality signature confirms the hardware is genuine NXP silicon, while SDM ensures the specific tag instance has not been duplicated or replayed. This layered approach provides the strongest commercially available defense against NFC counterfeiting.