I created the ultimate Wi-Fi password key with the most unsuspecting gadget - how it works

Source: ZDNet

One of my favorite technologies is NFC. I’m blown away that I can write data to a little chip and then access that using a phone or tablet. I’ve embedded NFC tags into all sorts of things, from documents to business cards to 3D‑printed objects. And it’s easy!

What you’ll need

• NFC tags – available as stickers, keychain disks, or plastic cards. I use NTAG215 compatible tags because they are cheap, have 504 bytes of memory, and a data‑retention lifespan of at least 10 years or 100 000 write cycles. (NTAG213 tags are cheaper but limited to 137 bytes.)
• NFC reader/writer app – I use NFC Tools, which works on both iOS and Android.

How to create an NFC tag

1. Open NFC Tools and tap Write.
2. Tap Add a record, choose URL/URI, and enter the web address you want the tag to open.
3. Tap OK, then bring the tag to the back of your smartphone. The app will detect the tag and write the data.

If you need to produce many tags, consider an industrial writer such as the Sato CT4‑LX.

How to test your NFC tag

1. Exit the NFC Tools app.
2. Bring the tag close to the back of your phone.
3. The phone should read the tag and prompt you to open the associated web page.

Securing the tag

NFC tags are rewritable, so you may want to protect them from tampering:

• Password‑protect the tag (useful for reusable tags and cards).
• Lock the tag (quicker for disposable stickers; no password needed).

Choose the method that fits your use case to prevent unauthorized changes.

Pro tip: Share your Wi‑Fi password with NFC

You can store Wi‑Fi credentials on an NFC tag:

1. In NFC Tools, add a Wi‑Fi Network record.
2. Enter your SSID, password, and security type.
3. Write the tag as described above.

Guests can simply tap their device on the tag to connect to your network—perfect for guest Wi‑Fi.