Can we use ECDH when CONFIG_BT_TINYCRYPT_ECC=n?

[victor zheng]

Hi Team

For some reason, I need to disable CONFIG_BT_TINYCRYPT_ECC. But I don't know if our BLE controller in NCS rely on Tinycrypt lib when it need support the ECDH  paring?

Can I use LE SC paring without TINYCRYPT lib in NCS? Thank you.

Regards

Victor

[Simon]

It does not seem like it's possible to use LESC pairing when CONFIG_BT_TINYCRYPT_ECC is disabled. I just tested this with the peripheral_uart sample.

I set these in the prj.conf

CONFIG_BT_TINYCRYPT_ECC=n
CONFIG_BT_SMP_SC_PAIR_ONLY=y

The option BT_SMP_SC_PAIR_ONLY will disable legacy pairing, such that only LESC pairing can be used. I got the following error:

"<err> bt_smp: SC Pair Only Mode selected but LE SC not supported"

I'm not very familiar with BLE Security in NCS, so I can't say no to the question below with certainty.

Can I use LE SC paring without TINYCRYPT lib in NCS? Thank you.

I've asked internally and will get back to you.

Best regards,

Simon

[victor zheng]

Hi Simon

The reply is very clear. Thank you for your help.

Victor