ST STM32WL5 Series User Manual

RM0453 Rev 1 713/1461
RM0453 Public key accelerator (PKA)
728
24.4.15 ECC Fp scalar multiplication
This operation consists in the computation of a k x P (x
P
, y
P
), where P is a point on a curve
over prime fields and “x” is the elliptic curve scalar point multiplication. Result of the
computation is a point that belongs to the same curve or a point at infinity.
Operation instructions for ECC Fp scalar multiplication are summarized in Table 160
(normal mode) and Table 161 (fast mode). Fast mode usage is explained in Section 24.3.6.
Table 159. Point on elliptic curve Fp check
Parameters with direction Value (Note) Storage Size
IN
MODE 0x28 PKA_CR 6 bits
Modulus length
(In bits, not null,
8 < value < 640)
RAM@0x404
32 bits
Curve coefficient a sign
0x0: positive
0x1: negative
RAM@0x408
Curve coefficient |a| (Absolute value, |a| < p) RAM@0x40C
EOS
Curve coefficient b (|b| < p) RAM@0x7FC
Curve modulus value p
(Odd integer prime,
0 < p < 2640)
RAM@0x460
Point P coordinate x (x < p) RAM@0x55C
Point P coordinate y (y < p) RAM@0x5B0
OUT Result: P on curve
0x0: point on curve
Not 0x0: point not on curve
RAM@0x400 32 bits
Table 160. ECC Fp scalar multiplication
Parameters with direction Value (Note) Storage Size
IN MODE 0x20 PKA_CR 6 bits
IN
Scalar multiplier k length
(In bits, not null,
8 < value < 640)
RAM@0x400
32 bitsModulus length
(In bits, not null,
8 < value < 640)
RAM@0x404
Curve coefficient a sign
0x0: positive
0x1: negative
RAM@0x408
IN
Curve coefficient |a| (Absolute value, |a| < p) RAM@0x40C
EOS
Curve modulus value p
(Odd integer prime,
0 < p < 2
640
)
RAM@0x460
Scalar multiplier k (0 ≤ k < 2
640
) RAM@0x508
Point P coordinate x
P
(x < p)RAM@0x55C
Point P coordinate y
P
(y < p) RAM@0x5B0
OUT
Result: k x P coordinate x (result < p)RAM@0x55C
Result: k x P coordinate y (result < p) RAM@0x5B0

ST STM32WL5 Series Specifications

General

Brand	ST
Model	STM32WL5 Series
Category	Microcontrollers
Language	English