Table 159. Point On Elliptic Curve Fp Check; Table 160. Ecc Fp Scalar Multiplication - STMicroelectronics STM32WL5 Series Reference Manual

RM0453
Parameters with direction
IN
OUT
24.4.15 ECC Fp scalar multiplication
This operation consists in the computation of a k x P (x
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
(normal mode) and
Parameters with direction
IN MODE
Scalar multiplier k length
IN Modulus length
Curve coefficient a sign
Curve coefficient |a|
Curve modulus value p
IN
Scalar multiplier k
Point P coordinate x
Point P coordinate y
Result: k x P coordinate x (result < p)
OUT
Result: k x P coordinate y (result < p)

Table 159. Point on elliptic curve Fp check

MODE
Modulus length
Curve coefficient a sign
Curve coefficient |a|
Curve coefficient b
Curve modulus value p
Point P coordinate x
Point P coordinate y
Result: P on curve
Table 161

Table 160. ECC Fp scalar multiplication

P
P
Value (Note)
0x28
(In bits, not null,
8 < value < 640)
0x0: positive
0x1: negative
(Absolute value, |a| < p)
(|b| < p)
(Odd integer prime,
0 < p < 2640)
(x < p)
(y < p)
0x0: point on curve
Not 0x0: point not on curve
(fast mode). Fast mode usage is explained in
Value (Note)
0x20
(In bits, not null,
8 < value < 640)
(In bits, not null,
8 < value < 640)
0x0: positive
0x1: negative
(Absolute value, |a| < p)
(Odd integer prime,
640
0 < p < 2 )
640
(0 ≤ k < 2 )
(x < p)
(y < p)
RM0453 Rev 5
Public key accelerator (PKA)
Storage
PKA_CR
RAM@0x404
RAM@0x408
RAM@0x40C
RAM@0x7FC
RAM@0x460
RAM@0x55C
RAM@0x5B0
RAM@0x400
, y ), where P is a point on a curve
P P
Table 160
Section
Storage
PKA_CR
RAM@0x400
RAM@0x404
RAM@0x408
RAM@0x40C
RAM@0x460
RAM@0x508
RAM@0x55C
RAM@0x5B0
RAM@0x55C
RAM@0x5B0
Size
6 bits
32 bits
EOS
32 bits
24.3.6.
Size
6 bits
32 bits
EOS
709/1450
720