Cryptographic performance on STM32WB Series

This page reports measured performance when using the pure software cryptographic library algorithms with an STM32WB MCU. In addition to performance figures, the required code footprint and memory are also given.

1. Measurement configuration

1.1. Hardware configuration

STM32 MCU	STM32WB55RG
Device ID	0x495
Revision ID	0x2001
Board	P-NUCLEO-WB55

1.2. Firmware configuration

Cryptographic Library version

040000B1^{[ver. 1]}

↑ This value corresponds to the information returned by a call to cmox_getInfos

1.3. System configuration

System Core Clock Frequency	64 MHz
Flash latency	3 wait states
Voltage scaling	Range 1
Instruction Cache (ART/ICU)	1 (0: disabled / 1: enabled)
Data Cache (ART/DCU)	1 (0: disabled / 1: enabled)
Prefetch Cache (ART)	1 (0: disabled / 1: enabled)

1.4. Development toolchains and compilers

IAR Embedded Workbench

IAR ANSI C/C++ Compiler V8.50.4.261/W32 for ARM

Information

NOTE: The measurements are done using a project built with High Speed optimization setting enabled.

2. Performance values

2.1. AES symmetric key encryption & decryption

This section provides the performance results for AES-CBC using different modes of operation:

Sole buffer: one sole buffer is encrypted or decrypted. Time to perform is given in µs.
Data flow: a big message is encrypted or decrypted by chunk. Bit rate is given in kilobytes per second.

2.1.1. Sole buffer mode

In this mode the entire encryption or decryption process, for the whole message size, is managed through a single API call provided by the CMOX library.

The table below shows the number of clock cycles and time (in µs) needed to perform the described operation in small and fast configurations.

AES mode	Key size	Buffer size	Cipher operation	Configuration	Cycles	Time
AES CBC	128 bits	32 bytes	Encryption	Small	5846	91 µs
AES CBC	128 bits	32 bytes	Encryption	Fast	6251	97 µs
AES CBC	128 bits	64 bytes	Encryption	Small	9287	145 µs
AES CBC	128 bits	64 bytes	Encryption	Fast	10 068	157 µs
AES CBC	128 bits	128 bytes	Encryption	Small	16 142	252 µs
AES CBC	128 bits	128 bytes	Encryption	Fast	17 656	275 µs
AES CBC	192 bits	32 bytes	Encryption	Small	6458	100 µs
AES CBC	192 bits	32 bytes	Encryption	Fast	6854	107 µs
AES CBC	192 bits	64 bytes	Encryption	Small	10 444	163 µs
AES CBC	192 bits	64 bytes	Encryption	Fast	11 258	175 µs
AES CBC	192 bits	128 bytes	Encryption	Small	18 416	287 µs
AES CBC	192 bits	128 bytes	Encryption	Fast	20 036	313 µs
AES CBC	256 bits	32 bytes	Encryption	Small	7344	114 µs
AES CBC	256 bits	32 bytes	Encryption	Fast	7855	122 µs
AES CBC	256 bits	64 bytes	Encryption	Small	11 873	185 µs
AES CBC	256 bits	64 bytes	Encryption	Fast	12 889	201 µs
AES CBC	256 bits	128 bytes	Encryption	Small	20 937	327 µs
AES CBC	256 bits	128 bytes	Encryption	Fast	22 921	358 µs
AES CBC	128 bits	32 bytes	Decryption	Small	9867	154 µs
AES CBC	128 bits	32 bytes	Decryption	Fast	8246	128 µs
AES CBC	128 bits	64 bytes	Decryption	Small	17 226	269 µs
AES CBC	128 bits	64 bytes	Decryption	Fast	12 218	190 µs
AES CBC	128 bits	128 bytes	Decryption	Small	31 942	499 µs
AES CBC	128 bits	128 bytes	Decryption	Fast	20 173	315 µs
AES CBC	192 bits	32 bytes	Decryption	Small	11 280	176 µs
AES CBC	192 bits	32 bytes	Decryption	Fast	9360	146 µs
AES CBC	192 bits	64 bytes	Decryption	Small	20 069	313 µs
AES CBC	192 bits	64 bytes	Decryption	Fast	13 954	218 µs
AES CBC	192 bits	128 bytes	Decryption	Small	37 600	587 µs
AES CBC	192 bits	128 bytes	Decryption	Fast	23 119	361 µs
AES CBC	256 bits	32 bytes	Decryption	Small	13 094	204 µs
AES CBC	256 bits	32 bytes	Decryption	Fast	10 691	167 µs
AES CBC	256 bits	64 bytes	Decryption	Small	23 271	363 µs
AES CBC	256 bits	64 bytes	Decryption	Fast	15 925	248 µs
AES CBC	256 bits	128 bytes	Decryption	Small	43 681	682 µs
AES CBC	256 bits	128 bytes	Decryption	Fast	26 378	412 µs

The table below shows Flash and RAM usage (in bytes).

Cipher operation	Configuration	Code	Constant data	Global data	Stack usage
Encryption	Small	2936 bytes	380 bytes	1 bytes	524 bytes
Encryption	Fast	3188 bytes	1404 bytes	1 bytes	548 bytes
Decryption	Small	3068 bytes	636 bytes	1 bytes	552 bytes
Decryption	Fast	3644 bytes	1660 bytes	1 bytes	556 bytes

2.1.2. Data flow mode

In this mode, operation is performed in several calls to the CMOX library APIs, as below:

cmox_cipher_init
cmox_cipher_setKey
cmox_cipher_setIV
cmox_cipher_append: called several times to encrypt or decrypt the whole message by chunk of fixed size

The table below shows the number of clock cycles and bit rate (in kilobytes per second) needed to perform described operation in small and in fast configuration.

AES mode	Key size	Message size	Chunk size	Cipher operation	Configuration	Cycles	Bit rate
AES CBC	128 bits	8000 bytes	128 bytes	Encryption	Small	874 960	585 kbyte/s
AES CBC	128 bits	8000 bytes	128 bytes	Encryption	Fast	969 024	528 kbyte/s
AES CBC	128 bits	8000 bytes	512 bytes	Encryption	Small	865 944	591 kbyte/s
AES CBC	128 bits	8000 bytes	512 bytes	Encryption	Fast	960 056	533 kbyte/s
AES CBC	128 bits	8000 bytes	1024 bytes	Encryption	Small	864 392	592 kbyte/s
AES CBC	128 bits	8000 bytes	1024 bytes	Encryption	Fast	958 704	534 kbyte/s
AES CBC	128 bits	8000 bytes	2048 bytes	Encryption	Small	863 608	592 kbyte/s
AES CBC	128 bits	8000 bytes	2048 bytes	Encryption	Fast	958 336	534 kbyte/s
AES CBC	192 bits	8000 bytes	128 bytes	Encryption	Small	1 012 088	505 kbyte/s
AES CBC	192 bits	8000 bytes	128 bytes	Encryption	Fast	1 122 432	456 kbyte/s
AES CBC	192 bits	8000 bytes	512 bytes	Encryption	Small	1 003 680	510 kbyte/s
AES CBC	192 bits	8000 bytes	512 bytes	Encryption	Fast	1 112 856	460 kbyte/s
AES CBC	192 bits	8000 bytes	1024 bytes	Encryption	Small	1 002 096	510 kbyte/s
AES CBC	192 bits	8000 bytes	1024 bytes	Encryption	Fast	1 111 088	460 kbyte/s
AES CBC	192 bits	8000 bytes	2048 bytes	Encryption	Small	1 001 464	511 kbyte/s
AES CBC	192 bits	8000 bytes	2048 bytes	Encryption	Fast	1 110 280	461 kbyte/s
AES CBC	256 bits	8000 bytes	128 bytes	Encryption	Small	1 150 336	445 kbyte/s
AES CBC	256 bits	8000 bytes	128 bytes	Encryption	Fast	1 275 136	401 kbyte/s
AES CBC	256 bits	8000 bytes	512 bytes	Encryption	Small	1 141 832	448 kbyte/s
AES CBC	256 bits	8000 bytes	512 bytes	Encryption	Fast	1 266 080	404 kbyte/s
AES CBC	256 bits	8000 bytes	1024 bytes	Encryption	Small	1 140 464	448 kbyte/s
AES CBC	256 bits	8000 bytes	1024 bytes	Encryption	Fast	1 264 432	404 kbyte/s
AES CBC	256 bits	8000 bytes	2048 bytes	Encryption	Small	1 139 680	449 kbyte/s
AES CBC	256 bits	8000 bytes	2048 bytes	Encryption	Fast	1 264 392	404 kbyte/s
AES CBC	128 bits	8000 bytes	128 bytes	Decryption	Small	1 880 776	272 kbyte/s
AES CBC	128 bits	8000 bytes	128 bytes	Decryption	Fast	1 028 896	497 kbyte/s
AES CBC	128 bits	8000 bytes	512 bytes	Decryption	Small	1 863 960	274 kbyte/s
AES CBC	128 bits	8000 bytes	512 bytes	Decryption	Fast	1 010 032	506 kbyte/s
AES CBC	128 bits	8000 bytes	1024 bytes	Decryption	Small	1 859 888	275 kbyte/s
AES CBC	128 bits	8000 bytes	1024 bytes	Decryption	Fast	1 006 504	508 kbyte/s
AES CBC	128 bits	8000 bytes	2048 bytes	Decryption	Small	1 856 056	275 kbyte/s
AES CBC	128 bits	8000 bytes	2048 bytes	Decryption	Fast	1 002 960	510 kbyte/s
AES CBC	192 bits	8000 bytes	128 bytes	Decryption	Small	2 233 624	229 kbyte/s
AES CBC	192 bits	8000 bytes	128 bytes	Decryption	Fast	1 187 432	431 kbyte/s
AES CBC	192 bits	8000 bytes	512 bytes	Decryption	Small	2 217 408	230 kbyte/s
AES CBC	192 bits	8000 bytes	512 bytes	Decryption	Fast	1 170 632	437 kbyte/s
AES CBC	192 bits	8000 bytes	1024 bytes	Decryption	Small	2 213 664	231 kbyte/s
AES CBC	192 bits	8000 bytes	1024 bytes	Decryption	Fast	1 166 576	438 kbyte/s
AES CBC	192 bits	8000 bytes	2048 bytes	Decryption	Small	2 209 952	231 kbyte/s
AES CBC	192 bits	8000 bytes	2048 bytes	Decryption	Fast	1 162 576	440 kbyte/s
AES CBC	256 bits	8000 bytes	128 bytes	Decryption	Small	2 588 088	197 kbyte/s
AES CBC	256 bits	8000 bytes	128 bytes	Decryption	Fast	1 346 928	380 kbyte/s
AES CBC	256 bits	8000 bytes	512 bytes	Decryption	Small	2 571 832	199 kbyte/s
AES CBC	256 bits	8000 bytes	512 bytes	Decryption	Fast	1 327 496	385 kbyte/s
AES CBC	256 bits	8000 bytes	1024 bytes	Decryption	Small	2 567 816	199 kbyte/s
AES CBC	256 bits	8000 bytes	1024 bytes	Decryption	Fast	1 323 832	386 kbyte/s
AES CBC	256 bits	8000 bytes	2048 bytes	Decryption	Small	2 564 048	199 kbyte/s
AES CBC	256 bits	8000 bytes	2048 bytes	Decryption	Fast	1 320 216	387 kbyte/s

The table below shows Flash and RAM usage (in bytes).

Cipher operation	Configuration	Code	Constant data	Global data	Stack usage
Encryption	Small	2828 bytes	372 bytes	1 bytes	140 bytes
Encryption	Fast	3080 bytes	1396 bytes	1 bytes	172 bytes
Decryption	Small	2960 bytes	628 bytes	1 bytes	176 bytes
Decryption	Fast	3536 bytes	1652 bytes	1 bytes	180 bytes

2.2. HASH digest

In this section we provide the performance results for HASH using different modes of operation:

Sole buffer: one sole buffer is hashed. Time to perform is given in us.
Data flow: a big message is hashed by chunk. Bit rate is given in bytes per s.

2.2.1. Sole buffer mode

In this mode, the entire message hashing process is managed through a single API call provided by the CMOX library.

The table below shows the number of clock cycles and time (in µs) needed to perform described operation.

HASH mode	Buffer size	Cycles	Time
SHA256	32 bytes	5690	88 µs
SHA256	64 bytes	9037	141 µs
SHA256	128 bytes	12 031	187 µs
SHA384	32 bytes	19 376	302 µs
SHA384	64 bytes	19 582	305 µs
SHA384	128 bytes	36 328	567 µs

The table below shows Flash and RAM usage (in bytes).

HASH mode	Code	Constant data	Global data	Stack usage
SHA256	1848	296 bytes	1 bytes	564 bytes
SHA384	3004	744 bytes	1 bytes	1124 bytes

2.2.2. Data flow mode

In this mode, operation is performed in several calls to the CMOX library APIs, as below:

cmox_hash_init
cmox_hash_append: called several times to hash the whole message by chunk of fixed size
cmox_hash_generateTag

The table below shows the number of clock cycles and bit rate (in kilobytes per second) needed to perform described operation.

HASH mode	Message size	Chunk size	Cycles	Bit rate
SHA256	8000 bytes	128 bytes	425 786	1202 kbyte/s
SHA256	8000 bytes	512 bytes	397 319	1288 kbyte/s
SHA256	8000 bytes	1024 bytes	392 537	1304 kbyte/s
SHA256	8000 bytes	2048 bytes	390 133	1312 kbyte/s
SHA384	8000 bytes	128 bytes	1 076 672	475 kbyte/s
SHA384	8000 bytes	512 bytes	1 028 028	498 kbyte/s
SHA384	8000 bytes	1024 bytes	1 019 596	502 kbyte/s
SHA384	8000 bytes	2048 bytes	1 015 380	504 kbyte/s

The table below shows final tag generation done through the call to cmox_hash_generateTag.

HASH mode	Cycles	Time
SHA256	4623	72 µs
SHA384	18 091	282 µs

The table below shows Flash and RAM usage (in bytes).

HASH mode	Code	Constant data	Global data	Stack usage
SHA256	1856 bytes	288 bytes	1 bytes	372 bytes
SHA384	3012 bytes	736 bytes	1 bytes	828 bytes

2.3. ECDSA signature & verification

In this section we provide the performance results for ECDSA signature & verification.

The table below shows the number of clock cycles and time (in ms) needed to perform described operation in different configurations.

Curve	Operation	ECC mathematics configuration	Curve definition	Cycles	Time
SECP256R1	Signature	Small	Low	3 075 208	48 ms
SECP256R1	Signature	Small	High	2 991 968	46 ms
SECP256R1	Signature	SuperFast	Low	2 694 104	42 ms
SECP256R1	Signature	SuperFast	High	2 608 416	40 ms
SECP256R1	Verification	Small	Low	7 448 632	116 ms
SECP256R1	Verification	Small	High	6 621 144	103 ms
SECP256R1	Verification	SuperFast	Low	6 549 376	102 ms
SECP256R1	Verification	SuperFast	High	5 794 800	90 ms
SECP384R1	Signature	Small	Low	8 388 992	131 ms
SECP384R1	Signature	Small	High	8 037 800	125 ms
SECP384R1	Signature	Fast	Low	8 304 872	129 ms
SECP384R1	Signature	Fast	High	7 939 504	124 ms
SECP384R1	Verification	Small	Low	20 196 544	315 ms
SECP384R1	Verification	Small	High	17 572 728	274 ms
SECP384R1	Verification	Fast	Low	19 993 632	312 ms
SECP384R1	Verification	Fast	High	17 381 696	271 ms

The table below shows ECDSA Flash and RAM usage (in bytes).

Curve	Operation	ECC mathematics configuration	Curve definition	Code	Constant data	Global data	Stack usage	Working buffer
SECP256R1	Signature	Small	Low	11 732 bytes	1184 bytes	1 bytes	328 bytes	628 bytes
SECP256R1	Signature	Small	High	11 732 bytes	1568 bytes	1 bytes	328 bytes	696 bytes
SECP256R1	Signature	SuperFast	Low	13 042 bytes	1184 bytes	1 bytes	332 bytes	628 bytes
SECP256R1	Signature	SuperFast	High	13 042 bytes	1568 bytes	1 bytes	332 bytes	696 bytes
SECP256R1	Verification	Small	Low	12 216 bytes	1200 bytes	1 bytes	424 bytes	856 bytes
SECP256R1	Verification	Small	High	12 216 bytes	1584 bytes	1 bytes	424 bytes	1648 bytes
SECP256R1	Verification	SuperFast	Low	13 526 bytes	1200 bytes	1 bytes	428 bytes	856 bytes
SECP256R1	Verification	SuperFast	High	13 526 bytes	1584 bytes	1 bytes	428 bytes	1648 bytes
SECP384R1	Signature	Small	Low	11 732 bytes	1664 bytes	1 bytes	328 bytes	884 bytes
SECP384R1	Signature	Small	High	11 732 bytes	2240 bytes	1 bytes	328 bytes	984 bytes
SECP384R1	Signature	Fast	Low	12 102 bytes	1664 bytes	1 bytes	344 bytes	884 bytes
SECP384R1	Signature	Fast	High	12 102 bytes	2240 bytes	1 bytes	344 bytes	984 bytes
SECP384R1	Verification	Small	Low	12 216 bytes	1680 bytes	1 bytes	424 bytes	1192 bytes
SECP384R1	Verification	Small	High	12 216 bytes	2256 bytes	1 bytes	424 bytes	2272 bytes
SECP384R1	Verification	Fast	Low	12 586 bytes	1680 bytes	1 bytes	440 bytes	1192 bytes
SECP384R1	Verification	Fast	High	12 586 bytes	2256 bytes	1 bytes	440 bytes	2272 bytes

2.4. EdDSA signature & verification

In this section we provide the performance results for EdDSA signature & verification.

The table below shows the number of clock cycles and time (in ms) needed to perform described operation in different configurations.

Curve	Message size	Operation	ECC mathematics configuration	Curve definition	Cycles	Time
Ed25519	1023 bytes	Signature	Small	OptLow	4 867 104	76 ms
Ed25519	1023 bytes	Signature	Small	OptHigh	2 848 296	44 ms
Ed25519	1023 bytes	Signature	SuperFast	OptLow	4 374 312	68 ms
Ed25519	1023 bytes	Signature	SuperFast	OptHigh	2 569 768	40 ms
Ed25519	1023 bytes	Verification	Small	OptLow	7 257 320	113 ms
Ed25519	1023 bytes	Verification	Small	OptHigh	6 367 608	99 ms
Ed25519	1023 bytes	Verification	SuperFast	OptLow	6 428 984	100 ms
Ed25519	1023 bytes	Verification	SuperFast	OptHigh	5 639 016	88 ms

The table below shows EdDSA Flash and RAM usage (in bytes).

Curve	Message size	Operation	ECC mathematics configuration	Curve definition	Code	Constant data	Global data	Stack usage	Working buffer
Ed25519	1023 bytes	Signature	Small	OptLow	14 088 bytes	1744 bytes	1 bytes	1236 bytes	1388 bytes
Ed25519	1023 bytes	Signature	Small	OptHigh	14 494 bytes	2896 bytes	1 bytes	1236 bytes	1388 bytes
Ed25519	1023 bytes	Signature	SuperFast	OptLow	15 398 bytes	1744 bytes	1 bytes	1236 bytes	1388 bytes
Ed25519	1023 bytes	Signature	SuperFast	OptHigh	15 804 bytes	2896 bytes	1 bytes	1236 bytes	1388 bytes
Ed25519	1023 bytes	Verification	Small	OptLow	14 178 bytes	1748 bytes	1 bytes	1244 bytes	1152 bytes
Ed25519	1023 bytes	Verification	Small	OptHigh	14 584 bytes	2900 bytes	1 bytes	1244 bytes	1992 bytes
Ed25519	1023 bytes	Verification	SuperFast	OptLow	15 488 bytes	1748 bytes	1 bytes	1244 bytes	1152 bytes
Ed25519	1023 bytes	Verification	SuperFast	OptHigh	15 894 bytes	2900 bytes	1 bytes	1244 bytes	1992 bytes

2.5. RSA signature & verification

In this section we provide the performance results for RSA signature & verification.

The table below shows the number of clock cycles and time (in ms) needed to perform described operation in different configurations.

PKCS#1	Priv. key mod. exp. method	Hash method	Modulus size	Operation	RSA mathematics configuration	Priv. key mod. exp. implementation	Cycles	Time
v2.2	CRT	SHA-256	3K	Signature	Small	Low	187 730 904	2933 ms
v2.2	CRT	SHA-256	3K	Signature	Small	Mid	141 318 672	2208 ms
v2.2	CRT	SHA-256	3K	Signature	Small	High	118 681 608	1854 ms
v2.2	CRT	SHA-256	3K	Signature	Fast	Low	187 024 936	2922 ms
v2.2	CRT	SHA-256	3K	Signature	Fast	Mid	140 843 192	2200 ms
v2.2	CRT	SHA-256	3K	Signature	Fast	High	118 266 136	1847 ms
v2.2	No CRT	SHA-256	3K	Signature	Small	Low	713 657 520	11 150 ms
v2.2	No CRT	SHA-256	3K	Signature	Small	Mid	536 044 336	8375 ms
v2.2	No CRT	SHA-256	3K	Signature	Small	High	448 383 472	7005 ms
v2.2	No CRT	SHA-256	3K	Signature	Fast	Low	712 427 032	11 131 ms
v2.2	No CRT	SHA-256	3K	Signature	Fast	Mid	535 159 896	8361 ms
v2.2	No CRT	SHA-256	3K	Signature	Fast	High	447 635 992	6994 ms
v2.2	n/a	SHA-256	3K	Verification	Small	n/a	3 822 504	59 ms
v2.2	n/a	SHA-256	3K	Verification	Fast	n/a	3 772 624	58 ms

The table below shows RSA Flash and RAM usage (in bytes).

PKCS#1	Priv. key mod. exp. method	Hash method	Modulus size	Operation	RSA mathematics configuration	Priv. key mod. exp. implementation	Code	Constant data	Global data	Stack usage	Working buffer
v2.2	CRT	SHA-256	3K	Signature	Small	Low	7034 bytes	370 bytes	5 bytes	700 bytes	3704 bytes
v2.2	CRT	SHA-256	3K	Signature	Small	Mid	7282 bytes	370 bytes	5 bytes	700 bytes	4308 bytes
v2.2	CRT	SHA-256	3K	Signature	Small	High	7282 bytes	370 bytes	5 bytes	700 bytes	6708 bytes
v2.2	CRT	SHA-256	3K	Signature	Fast	Low	7404 bytes	370 bytes	5 bytes	700 bytes	3704 bytes
v2.2	CRT	SHA-256	3K	Signature	Fast	Mid	7652 bytes	370 bytes	5 bytes	700 bytes	4308 bytes
v2.2	CRT	SHA-256	3K	Signature	Fast	High	7652 bytes	370 bytes	5 bytes	700 bytes	6708 bytes
v2.2	No CRT	SHA-256	3K	Signature	Small	Low	6064 bytes	362 bytes	5 bytes	700 bytes	3484 bytes
v2.2	No CRT	SHA-256	3K	Signature	Small	Mid	6312 bytes	362 bytes	5 bytes	700 bytes	4664 bytes
v2.2	No CRT	SHA-256	3K	Signature	Small	High	6312 bytes	362 bytes	5 bytes	700 bytes	9368 bytes
v2.2	No CRT	SHA-256	3K	Signature	Fast	Low	6434 bytes	362 bytes	5 bytes	700 bytes	3484 bytes
v2.2	No CRT	SHA-256	3K	Signature	Fast	Mid	6682 bytes	362 bytes	5 bytes	700 bytes	4664 bytes
v2.2	No CRT	SHA-256	3K	Signature	Fast	High	6682 bytes	362 bytes	5 bytes	700 bytes	9368 bytes
v2.2	n/a	SHA-256	3K	Verification	Small	n/a	6810 bytes	366 bytes	5 bytes	716 bytes	3108 bytes
v2.2	n/a	SHA-256	3K	Verification	Fast	n/a	7180 bytes	366 bytes	5 bytes	716 bytes	3108 bytes

[1] This value corresponds to the information returned by a call to cmox_getInfos

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