NTAG X DNA vs NTAG 424 DNA: What NXP's Newer Chip Adds

NTAG X DNA vs NTAG 424 DNA in short

The NTAG X DNA is the bigger, more secure chip: NXP lists it as Common Criteria EAL 6+, with up to 16 kB of memory, PKI and AES-256, plus an I2C side. The NTAG 424 DNA is the smaller, tag-only chip that most tap-to-verify labels use today. If all you need is a tap that proves a label is real, the older chip is often enough. If a device has to prove itself to a cloud or a microcontroller, the newer one is built for that.

What the NTAG 424 DNA already does

According to NXP's NTAG 424 DNA page, the chip holds 416 bytes in an ISO/IEC 7816-4 file system: a 32-byte capability container, a 256-byte NDEF file and a 128-byte protected data file. It authenticates with AES-128, or with LRP-wrapped AES for stronger attack resistance, and it is certified to Common Criteria EAL4.

Its headline feature is SUN (Secure Unique NFC). The tag builds a signed, changing URL inside an ordinary NDEF read, so your phone needs no special app to fetch it. We cover that flow in how SUN and SDM work on the NTAG 424 DNA. NXP also lists a TagTamper variant with a tamper loop.

What is new in the NTAG X DNA

NXP's NTAG X DNA page describes a Type 4 connected tag that is also a secure companion chip to a standard MCU or MPU.

Security

NXP lists Common Criteria EAL 6+, AES-128 and AES-256 in several modes (ECB, CBC, CMAC, CCM and GCM), SHA-256 and SHA-384, HMAC and HKDF. The big shift is asymmetric crypto: ECDSA and ECDH on NIST P-256 and Brainpool P256r1, with key management and provisioning through PKI. NXP's EdgeLock 2GO service handles secure UID and certificate delivery. A vendor comparison on RFIDCard also notes on-chip ECC key generation. The 424 DNA, by contrast, relies on AES-128 plus an ECC-based originality signature.

Memory

Where the 424 DNA has 416 bytes, the X DNA offers up to 16 kB of memory with an ISO 7816 file system and a nonreversible monotonic counter.

Two interfaces instead of one

The 424 DNA only talks over the contactless interface. The X DNA does that too (ISO/IEC 14443-4, NFC Forum Type 4, up to 848 kbit/s, 7-byte or 10-byte UID, silent mode) and adds an I2C target running up to 1 MHz, with two GPIOs and downstream power of up to 20 mW. So a phone and the product's own microcontroller can both reach the same chip. If that idea is new, see NFC tags that talk to a microcontroller over I2C.

Which chip fits which job

NXP points the 424 DNA at anti-counterfeiting, personalized content and supply-chain traceability. For the X DNA, it names consumer items such as chargers and appliances, plus industrial uses such as batteries, EV charging equipment and healthcare, and says it supports Digital Product Passport requirements. For background, read the EU Digital Product Passport and why NFC is on the table.

One caution. The X DNA is a newer product, and vendor pages differ on small figures. Check the current NXP data sheet before you design around a number.

The bottom line

The NTAG X DNA is a step up in security, memory and connectivity, and it aims at devices rather than labels. The NTAG 424 DNA stays the simpler fit for a sticker that proves a product is real. Either way, you can try a tap on your own tags with NFCore on the App Store or Google Play.

Frequently Asked Questions

Is the NTAG X DNA a drop-in replacement for the NTAG 424 DNA?

Not on NXP's own pages. Both are NFC Forum Type 4 tags with SUN authentication, but the X DNA adds PKI, more memory and an I2C side, so check a system built around one before swapping in the other.

Does the NTAG X DNA work with any phone?

NXP says it works with any NFC-enabled phone, and it is a Type 4 tag on ISO/IEC 14443-4.

Does the NTAG X DNA have a tamper-loop version?

NXP's X DNA page does not mention one. The TagTamper variant is listed for the NTAG 424 DNA.