Performance on hardware (cc3xx) is significantly slower than performance on software (oberon). Does anyone have a good explanation for this? I have also tested ECDSA and can see that hardware is faster. I also tried a different elliptic curve, but the result is the same.
I added the performance code, everything else and more can be found in nrf/samples/crypto/ecdh.
Development setup:
Macbook Air Apple M1
Toolchain version: 2.6.0
nRF5340 Development Kit board
This is my main.c file:
This is my prj.conf:
This is my nrf5340dk_nrf5340_cpuapp.conf:
This is my main.c file:
/*
* Copyright (c) 2021 Nordic Semiconductor ASA
*
* SPDX-License-Identifier: LicenseRef-Nordic-5-Clause
*/
#include <zephyr/kernel.h>
#include <zephyr/sys/printk.h>
#include <zephyr/logging/log.h>
#include <stdio.h>
#include <stdlib.h>
#include <psa/crypto.h>
#include <psa/crypto_extra.h>
#include <zephyr/timing/timing.h>
#include <math.h>
#include <zephyr/drivers/timer/system_timer.h>
#include <zephyr/sys/__assert.h>
#ifdef CONFIG_BUILD_WITH_TFM
#include <tfm_ns_interface.h>
#endif
#define APP_SUCCESS (0)
#define APP_ERROR (-1)
#define APP_SUCCESS_MESSAGE "Example finished successfully!"
#define APP_ERROR_MESSAGE "Example exited with error!"
#define PRINT_HEX(p_label, p_text, len)\
({\
LOG_INF("---- %s (len: %u): ----", p_label, len);\
LOG_HEXDUMP_INF(p_text, len, "Content:");\
LOG_INF("---- %s end ----", p_label);\
})
LOG_MODULE_REGISTER(ecdh, LOG_LEVEL_DBG);
/* ====================================================================== */
/* Global variables/defines for the ECDH example */
#define NRF_CRYPTO_EXAMPLE_ECDH_KEY_BITS (256)
#define NRF_CRYPTO_EXAMPLE_ECDH_PUBLIC_KEY_SIZE (65)
psa_key_id_t key_id_alice;
/* ====================================================================== */
int crypto_init(void)
{
psa_status_t status;
/* Initialize PSA Crypto */
status = psa_crypto_init();
if (status != PSA_SUCCESS)
return APP_ERROR;
return APP_SUCCESS;
}
int create_ecdh_keypair(psa_key_id_t *key_id)
{
psa_status_t status;
psa_key_attributes_t key_attributes = PSA_KEY_ATTRIBUTES_INIT;
/* Crypto settings for ECDH using the SHA256 hashing algorithm,
* the secp256r1 curve
*/
psa_set_key_usage_flags(&key_attributes, PSA_KEY_USAGE_DERIVE);
psa_set_key_lifetime(&key_attributes, PSA_KEY_LIFETIME_VOLATILE);
psa_set_key_algorithm(&key_attributes, PSA_ALG_ECDH);
psa_set_key_type(&key_attributes, PSA_KEY_TYPE_ECC_KEY_PAIR(PSA_ECC_FAMILY_SECP_R1));
psa_set_key_bits(&key_attributes, 256);
/* Generate a key pair */
status = psa_generate_key(&key_attributes, key_id);
if (status != PSA_SUCCESS) {
LOG_INF("psa_generate_key failed! (Error: %d)", status);
return APP_ERROR;
}
psa_reset_key_attributes(&key_attributes);
// LOG_INF("ECDH keypair created successfully!");
return APP_SUCCESS;
}
int main(void)
{
psa_status_t status;
/* Init crypto */
status = crypto_init();
if (status != APP_SUCCESS) {
LOG_INF(APP_ERROR_MESSAGE);
return APP_ERROR;
}
/* Create the ECDH key pairs for Alice and Bob */
timing_t start_time, end_time;
uint64_t total_cycles = 0;
uint64_t sum_squared = 0;
uint64_t min_cycles = UINT64_MAX;
uint64_t max_cycles = 0;
char* benchmark_name = "ECDH Keypair Generation";
int runs = 100;
printf("Starting %s benchmark (%d runs)...\n", benchmark_name, runs);
// Warm-up run
status = create_ecdh_keypair(&key_id_alice);
if(status != APP_SUCCESS) {
printf("%s warm-up failed with %d\n", benchmark_name, status);
}
psa_destroy_key(key_id_alice);
timing_init();
timing_start();
for(int i = 0; i < runs; i++) {
start_time = timing_counter_get();
// Function to benchmark
status = create_ecdh_keypair(&key_id_alice);
end_time = timing_counter_get();
if(status != APP_SUCCESS) {
printf("%s error on run %d\n", benchmark_name, i);
runs = i;
break;
}
uint64_t cycles = timing_cycles_get(&start_time, &end_time);
total_cycles += cycles;
sum_squared += cycles * cycles;
if(cycles < min_cycles) {
min_cycles = cycles;
}
if(cycles > max_cycles) {
max_cycles = cycles;
}
psa_destroy_key(key_id_alice);
}
timing_stop();
printf("Frequency: %u MHz\n", timing_freq_get_mhz());
double mean = total_cycles / runs;
double var = (sum_squared - ((total_cycles * total_cycles) / runs)) / (runs - 1);
double std = sqrt(var);
printf("%s benchmark results:\n", benchmark_name);
printf(" Runs: %d\n", runs);
printf(" Total: %llu cycles\n", total_cycles);
printf(" Average: %.3f cycles\n", mean);
printf(" Minimum: %llu cycles\n", min_cycles);
printf(" Maximum: %llu cycles\n", max_cycles);
printf(" Std: %.3f cycles\n", std);
return APP_SUCCESS;
}This is my prj.conf:
# The Zephyr CMSIS emulation assumes that ticks are ms, currently CONFIG_SYS_CLOCK_TICKS_PER_SEC=1000 CONFIG_MAIN_STACK_SIZE=4096 CONFIG_HEAP_MEM_POOL_SIZE=4096 # Enable logging CONFIG_CONSOLE=y CONFIG_LOG=y # Enable nordic security backend and PSA APIs CONFIG_NRF_SECURITY=y CONFIG_MBEDTLS_PSA_CRYPTO_C=y CONFIG_MBEDTLS_ENABLE_HEAP=y CONFIG_MBEDTLS_HEAP_SIZE=8192 CONFIG_PSA_WANT_ALG_ECDH=y CONFIG_PSA_WANT_KEY_TYPE_ECC_KEY_PAIR=y CONFIG_PSA_WANT_ECC_SECP_R1_256=y # For key generation CONFIG_PSA_WANT_GENERATE_RANDOM=y # Timing functions CONFIG_TIMING_FUNCTIONS=y CONFIG_CBPRINTF_FP_SUPPORT=y
This is my nrf5340dk_nrf5340_cpuapp.conf:
# Using hardware crypto accelerator CONFIG_PSA_CRYPTO_DRIVER_OBERON=n CONFIG_PSA_CRYPTO_DRIVER_CC3XX=y
When I run this with CONFIG_PSA_CRYPTO_DRIVER_OBERON=y and CONFIG_PSA_CRYPTO_DRIVER_CC3XX=n, I get this output:
*** Booting nRF Connect SDK v3.5.99-ncs1 ***
Starting ECDH Keypair Generation benchmark (100 runs)...
Frequency: 64 MHz
ECDH Keypair Generation benchmark results:
Runs: 100
Total: 1149048 cycles
Average: 11490.000 cycles
Minimum: 11490 cycles
Maximum: 11520 cycles
Std: 3.000 cycles
*** Booting nRF Connect SDK v3.5.99-ncs1 ***
but running it with CONFIG_PSA_CRYPTO_DRIVER_OBERON=n and CONFIG_PSA_CRYPTO_DRIVER_CC3XX=y, I get this output:
*** Booting nRF Connect SDK v3.5.99-ncs1 ***
Starting ECDH Keypair Generation benchmark (100 runs)...
Frequency: 64 MHz
ECDH Keypair Generation benchmark results:
Runs: 100
Total: 97657851 cycles
Average: 976578.000 cycles
Minimum: 929049 cycles
Maximum: 1014195 cycles
Std: 13743.361 cycles
*** Booting nRF Connect SDK v3.5.99-ncs1 ***