Find a chip that will support contactless NFC or BLE

[conorpp]

No description provided.

[mkroman]

I was looking at the infamous PN532, but the added footprint on the PCB would maybe pose a problem.

I also looked at the PN746X/736X series (Digikey), which seems like a possible option - it could replace the microcontroller - assuming 20 MHz is fast enough, and with the added feature of additional RAM and FLASH.

Thoughts?

[conorpp]

Hey thanks for looking into this! Finding something that would solve both NFC and USB would be ideal. Alternatively, slapping on another chip that only does NFC can also work. The problem with a lot of NFC chips is that they won't support the security and performance requirements.

1. Needs to have good entropy for key generation (TRNG). The most important.
2. Needs to be tamper resistant such that no one would be able to dump sensitive information with quick physical access.
3. Needs to compute ECC operations in under ~0.5s. A chip that just uses a 8051 or similar 8 bit architecture would probably take 5-10s to compute a signature. So hardware acceleration or a pipe lined 32 bit architecture should be considered.

The best NFC chips I've found is by NXP in their authentication category. However I don't think they use regular distributors for them and I haven't been able to contact NXP to learn more about sampling or developing. The chips could be viable for an open source project but probably not for a DIY project.

[scott-42]

You should be able to get NXP's A7005 line and the other NFC auth line at Mouser for quantity and direct from NXP for samples. Mouser NXP A7005CGHN1

[doanerock]

This would be a big plus if it worked with NFC.

[adricasti]

Since FIDO has provisions for Bluetooth, USB and NFC (bun 🍔), maybe you could try Nordic nRF52

[conorpp]

I think Nordic would be a great option for Bluetooth LE. Plus Bluetooth can be supported on iOS, unlike NFC.

Tricky part is power. My best thought is to include a small 20-30 mAh battery which could last for weeks and then charge quickly over USB interface. But then having a battery can have some safety complications so a case would need to be included as well.

[rcludwick]

Version 0 of the bluetooth LE stick might be for people to provide their own power through a usb battery pack. Also they do make NiMH button cells which should be safer than a lithium cell: https://goo.gl/r29KJL

[yangwao]

As I have in my hand NXP NTAG216 (compatible with all ISO14443A RFID systems) I would appreciate this, also BLE is way to go 🚀 .
Also, I can help w/ testing.
edit I would buy two pcs. 🔐 🔏

[conorpp]

I most likely won't start a NFC/BLE version because of time so it would have to be someone else. I can help though.

[conorpp]

Another awesome chip by Silicon Labs

Has RNG, P256 ECC, small package.

[AkosLukacs]

What about nRF52840?
USB, Bluetooth, NFC, "ARM® TrustZone® Cryptocell 310 security subsystem".
Or it's already done by SoloKeys, and should not practice issue-necromancy? :)