Table 168. Modular Exponentiation Computation Times; Table 169. Ecc Scalar Multiplication Computation Times; Table 170. Ecdsa Signature Average Computation Times - STMicroelectronics STM32WL5 Series Reference Manual

RM0453
24.5.2 Computation times
The following tables summarize the PKA computation times, expressed in clock cycles.
Exponent length
(in bits)
17
16
2
1024
2048
3072
1. CRT stands for chinese remainder theorem optimization (MODE bitfield = 0x07).
Mode
Normal
Fast
1. These times depend on the number of "1"s included in the scalar parameter.
160
1760000
1. These values are average execution times of random moduli of given length, as they depend upon the
length and the value of the modulus.
2. The execution time for the moduli that define the finite field of NIST elliptic curves is shorter than that
needed for the moduli used for Brainpool elliptic curves or for random moduli of the same size.

Table 168. Modular exponentiation computation times

Mode
Normal
3
Fast
Normal
Fast
Normal
+ 1
Fast
Normal
Fast
(1)
CRT
Normal
Fast
(1)
CRT
Normal
Fast
(1)
CRT

Table 169. ECC scalar multiplication computation times

160 192
1634000 2500000
1630000 2494000

Table 170. ECDSA signature average computation times

192
2664000 5249000
Modulus length (in bits)
1024
304000
46000
326000
68000
416000
158000
11664000
11280000
3546000
-
-
-
-
-
-
Modulus length (in bits)
256 320
4924000 8508000
4916000 8494000
Modulus length (in bits)
256 320
9016000
RM0453 Rev 5
Public key accelerator (PKA)
2048
814000
164000
896000
246000
1222000
572000
-
-
-
83834000
82046000
23468000
-
-
-
(1)
384 512
13642000 28890000
13614000 28842000
(1) (2)
384 512
14596000 30618000
3072
1728000
356000
1910000
534000
2616000
1244000
-
-
-
-
-
-
274954000
273522000
73378000
521
33160000
33158000
521
35540000
715/1450
720