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NFC hardware

The hardware layer is the physical anchor of the ORACULS stack (Oracle-Augmented Chain for Universal Logistics Security): secure NFC chips that cryptographically bind a physical item to its on-chain digital twin. Every chip in the portfolio produces an unclonable, authenticated tap — SUN (Secure Unique NFC) is the floor across every tier, and there is no no-crypto tier.

Legacy, not supported: NTAG 213 / 215 / 216 have no on-chip cryptography, cannot produce a SUN tap, and are never recommended for new work.

NTAG 424 DNA — the workhorse

SUN authentication

SUN provides cryptographic proof that a specific physical chip was present at the moment of scanning — a plain URL or QR code can be copied; a SUN tap cannot. On every read, the chip's Secure Dynamic Messaging engine rewrites two mirrors inside the stored NDEF URL: an AES-128-encrypted PICC block carrying the chip's UID and its rolling read counter, and an AES-CMAC over that block. Both keys never leave the chip's secure memory.

https://verify.tagit.network/sun?picc=EF963FF7828658A599F3041510671E88&cmac=94EED9EE65337086

The UID and counter are not in the clear — that is the point of the encrypted PICC mirror, and it is why a reader cannot correlate taps across deployments without the key. Anything documenting this URL as ?uid=…&ctr=…&mac=… is describing a plaintext layout this chip does not emit; that form appeared in earlier revisions of this page and the path it used does not exist.

The verifier decrypts picc and checks the CMAC server-side, which yields:

• Anti-cloning — the CMAC can only be produced by the chip holding the secret key; copying the URL yields a stale counter/CMAC pair that fails validation.
• Anti-replay — the server tracks the last-seen counter per UID. A tap with a counter at or below the last-seen value is rejected as a replay, and abnormal counter jumps raise a fraud alert.
• Tamper evidence — TagTamper variants permanently record loop status in the SUN message (see modifiers below).

A valid SUN tap resolves to the tag's on-chain digital twin on Base Sepolia. The envelope is uniform across chip tiers — every TAG IT chip exposes a verify URL that resolves to the correct twin — but how each tier proves the pointer differs, and that variation is handled server-side by the verifier. It is not abstracted in the TypeScript SDK: that package covers the ERC-8004 agent layer only and has no NFC, SUN or chip surface of any kind.

Chip tiers — item level

The tier menu trades cost against memory, certification level, and key architecture. The crypto floor never drops below AES-128 + SUN.

Tamper is a modifier, not a tier

A tamper loop can be layered on top of any chip in the table:

• Tamper-evident — NTAG 22x DNA StatusDetect / NTAG 424 DNA TagTamper: the chip keeps working after removal but permanently flags the broken loop in the SUN message on every subsequent tap.
• Tamper-killing — a frangible, destructible substrate (converter specification): the antenna physically destroys itself on peel, leaving a dead tag.

Package & pallet layer

Item-level DNA chips pair with a longer-range RFID layer for case-, pallet-, and logistics-level identification. One deployment spans item → package → pallet, and both layers carry the same resolvable GS1 Digital Link URL — which also makes the package layer EU Digital Product Passport (DPP) compatible.

Why two layers: HF/NFC (ICODE plus the DNA tags) is tap-range and phone-readable — right for consumers and item authentication. UHF RAIN (UCODE) reads at distance and in bulk — right for dock doors, conveyors, and warehouse portals.

Provisioning a tag

Provisioning turns a blank chip into a bound, verifiable tag. Keys are injected in a controlled environment and never transmitted or stored on chain — the contracts hold only a Keccak-256 commitment to the tag.

1. Read the UID from the blank chip (7 bytes, factory-programmed).
2. Inject keys — authenticate with the factory default key, then rotate per-tag AES-128 keys into the chip's key slots. Keys are generated in an HSM and registered against the UID in the key-management service.
3. Write the NDEF template — the SUN URL with mirror placeholders for uid, ctr, and mac, and enable Secure Dynamic Messaging so the chip fills them in live on every tap.
4. Lock the configuration — set NDEF read-only, enable counter-on-read, and permanently lock security settings so they cannot be altered after issuance.
5. Bind on chain — compute the tag commitment and call bindTag() on the minted twin, moving it MINTED → BOUND in the asset lifecycle.
6. Verify with a test scan — confirm the CMAC validates, the counter increments, and the URL resolves to the correct on-chain twin.

Readers

Consumers need no hardware at all — any NFC-capable smartphone performs a full SUN verification tap. For desk-side enrollment and provisioning, the TAG IT admin console uses the ACR1252U USB reader (PC/SC compliant, ~$80–100).

Next steps

• Asset Lifecycle — what bindTag() and the 7-state machine do on chain
• Security Model — where chip cryptography sits in the 5-layer architecture
• TypeScript SDK — the verification envelope abstraction in @tagit/sdk