Public-key 28bits instead of required 57bits / NRF51822

[NWolkow]

Hi guys,

I'm a noob but trying my best to figure out how things are done.

As my Intel MacbookPro giving me trouble flashing any of those possible devices I'm just using it for tracking. Flashing is done via a Linux setup (command line) which helped me to flash an ESP32 which now works and gets perfectly tracked via the app on my Macbook.

Now I was trying to flash a NRF51822 beacon with my Linux machine (and and ST-Link v2) but it stops early with an error concerning the public-key which is obviously expected to be 57 bits by the code but the public-key given by openhaystack for the new device (base64) obviously only has 28bits.

I can't figure out why, I searched through the "issues", did googling but haven't found any hints.

Any help?

Thx & BR

NWolkow

[Sn0wfreezeDev]

It's about the presentsation of the public key. You can present them as just an x-value or x and y value. We use the shortest representation, because it works fine for Diffie-Hellmann.

You can read all details in this really good chapter about ECC: https://cryptobook.nakov.com/asymmetric-key-ciphers/elliptic-curve-cryptography-ecc