xNT NFC Chip

Passive RFID and NFC chips are batteryless, magnetically coupled devices that power themselves and communicate data over a shared magnetic field that the reader generates. This means their effective read range and performance depends entirely on how well the antenna coils of both the chip and reader couple with each other. This typically means the shape, size, and orientation of both antennas must be complimentary.

Unfortunately, most reader devices, including NFC enabled smartphones, typically have antennas designed with thin PCB traces made into blocky rectangular shapes that lay along a flat plane. These antenna designs are great for coupling with and reading large flat labels and access cards which also share this antenna shape, but they have a hard time coupling to the very small cylindrical antenna coil inside our x-series chip implants. Most mobile phones and reader devices do have “sweet spots” that must be located and used each time to get consistent results. You should not expect your USB reader or NFC enabled mobile device to achieve the same read range with our x-series chips that you normally get with an NFC label, sticker, or card.

Locating the “sweet spot”
Not only is the correct location of a sweet spot necessary to find, but also the correct orientation. The best performance is achieved when the x-series lays across the antenna pathway of the reader antenna coil so the length of the x-series chip implant is perpendicular to the reader antenna coil. To help find an effective location and orienation to get the best read performance for your x-series chip implant, we created the X Field Detector. This diagnostic device mimics the cylidrical x-series antenna coil winding and shows you the best possible location and rotation/orientation for holding your x-series transponder up to any reader by lighting up when the field coupling is strong enough to power the LED inside. Watch this video to understand how to use it.

Our x-series transponders are typically installed into the webbing between the metacarpal bones of the index finger and thumb, resting parallel to the index metacarpal. They should be at least 5mm away from any bone or other implants to avoid possible impacts. The reason chip implants are usually installed in the hand has to do with the extremely short read range of most small chip implants. In the case of access control where the chip must be presented dirctly to a fixed reader of some kind, the hand is easily able to be properly positoned in front of the reader. To find out more about common installation locations of the hand, visit https://dngr.us/locations

Achieving a safe installation definitely requires skill and experience performing aseptic procedures. Dangerous Things prefers our customers locate one of our professional body piercing or body modification partners to complete the installation of our products. If no partners are available in your area, you should be able to follow this guide to finding a professional in your area. For aftercare information and what to expect, please read our X-Series FAQ page.

Testing Process
Our x-series chip implants come pre-loaded inside injector systems with steel needles, and because of this they cannot typically be read while packed inside the needle. This is why we perform a full test on every x-series tag before it is loaded into the injector assembly and sterilized. We have also conducted several tests on our x-series chips and cataloged those tests here.

Return Policy
We offer a 30-day money back guarantee! Read all about it on our return policy page.

Lifetime Warranty
If you do purchase one of our products and experience a failure, we offer a full lifetime warranty on all of our implant products. You will need to return the product for testing and analysis, and if it is determined to be malfunctioning, we will ship you a replacement free of charge. Read all about it on our warranty policy page.

Why is this important?
The NFC chip inside this product is an NTAG family chip from NXP. This chip type was designed for use in more typical NFC applications such as smart posters, labels, and other disposable use cases where the memory contents would typically be written and then locked so it could not be changed. This is done using built-in “lock bytes” which are OTP (one time programmable). That means that once the lock bytes are turned on to protect memory blocks, they can never be unlocked. Once any memory block is locked, it will forever be read-only, which is not ideal for a chip implant. Also, many common NFC smartphone apps and software applications offer ways to “lock” or “protect” your tag, making it very easy to accidentally lock your xNT as read-only.

In addition to lock bytes, the NTAG offers a 32bit password protection function. It can be used to password-protect just writing to or both reading from and writing to the user memory space of the NTAG chip. Regardless of what some NFC smartphone apps indicate, it is not possible to remove or disable the password, it is only possible to set the password to the factory default hexadecimal value of 0xFF 0xFF 0xFF 0xFF. If the password is not changed from the factory default then anyone could easily authenticate, change your password, then write data or change protection options for your chip implant to lock you out of your own chip.

Finally, many of the critical configuration bytes used by NTAG chips are stored in the last few pages of the chip’s memory. This means that it may be possible for an NFC application that does not properly detect or honor the memory schema of the chip to accidentally attempt to write NDEF record data (the data you’re trying to store on the chip) overtop of the configuration bytes. For example, if the data you are attempting to write is longer than the memory pages available, the remainder of the data might be written overtop of configuration bytes, which contain settings that are potentially dangerous to modify. Accidentally writing to those memory pages could result in your chip’s configuration being irreversibly locked.

How do we solve these problems?
To help our customers protect their tag from accidental modification or malicious attack, we have developed Dangerous NFC for Android. Our DNFC app allows customers to secure their tag by doing the following things;

• Disable lock bytes so they cannot be used to lock any memory blocks as read-only
• Update the password block with a custom, non-default password value
• Update the memory protection option to write-only protection
• Update the memory protection range to protect the configuration bytes

This approach allows the entire user memory space to be written to/updated, while at the same time protecting the configuration bytes and password values at the bottom end of the xNT memory space. This means an application cannot accidentally write data unintentionally to any configuration bytes. It also means the password of the xNT cannot be updated without first authenticating. This means you will need the current password in order to update or change the password. Without updating the dynamic memory protection range, it would technically be possible to just write a new password without first knowing the old password.

Ultimately, once secured by Dangerous NFC, you are free to use any other NFC app to write data to the tag and not need to be afraid of accidentally locking the tag, or changing the configuration bytes, or someone maliciously locking your tag or changing your password. We suggest using NXP’s TagWriter app.

You have questions! That’s understandable. The short answer is; it’s all good. If you’re looking for more specific answers, we have an extensive FAQ page that deals with many of the most commonly asked questions regarding installation of our x-series transponders.

• 13.56MHz NXP NTAG216 ISO14443A & NFC Type 2 chip
• Full datasheet for the NXP NTAG216 RFID/NFC chip
• 7 byte UID and 886 bytes of user read/write memory
• 10 year data retention. Rated for 100k writes per memory block.
• Encased in 2.1mm by 12mm bioglass with non-toxic epoxy
• Pre-tested and pre-loaded into sterile injection assembly
• No “anti-migration” coating means easy removal/replacement