LE Secure key generation performance

RE: LE Secure key generation performance

Einar Thorsrud — Mon, 22 Nov 2021 20:24:47 GMT

Ah, I never thought to test without optimization. Oberon is distributed as a prebuilt binary, so in that case it will always be built with optimization (by us) regardless of how you build your app.

RE: LE Secure key generation performance

JZone — Mon, 22 Nov 2021 17:49:42 GMT

We use MBED-TLS – Optimization level 0

After switching to

Oberon – Optimization 0/1 we are down to ~45ms

RE: LE Secure key generation performance

Einar Thorsrud — Wed, 17 Nov 2021 11:38:25 GMT

Hi,

That is not expected. I tested the ble_app_hrs with a nRF52 DK in SDK 17.1.0 and toggled a GPIO before and after the call to nrf_ble_lesc_keypair_generate() in nrf_ble_lesc_init() in components\ble\peer_manager\nrf_ble_lesc.c. With the default configuration this took 25 ms. To experiment I also chagned NRF_CRYPTO_BACKEND_NRF_HW_RNG_MBEDTLS_CTR_DRBG_ENABLED to 0 in sdk_config.h to see if that could explain what you saw, but that just increased the time to 44 ms.

How have you verified that this takes 2.5s? Which nrf_crypto backend do you use? Could there be other things happening here as well?