RM0453 Rev 5 697/1450
RM0453 Public key accelerator (PKA)
720
PKA operating modes
The list of operations the PKA can perform is detailed in Table 144 and Table 145,
respectively, for integer arithmetic functions and prime field (Fp) elliptic curve functions.
Each of these operating modes has an associated code that has to be written to the MODE
field in the PKA_CR register.
Montgomery space and fast mode operations
For efficiency reason the PKA internally performs modular multiply operations in the
Montgomery domain, automatically performing inward and outward transformations.
As Montgomery parameter computation is time consuming the application can decide to use
a faster mode of operation, during which the precomputed Montgomery parameter is
Table 144. PKA integer arithmetic functions list
PKA_CR.MODE[5:0]
Performed operation Reference
Hex Binary
0x01 000001 Montgomery parameter computation R2 mod n Section 24.4.2
0x0E 001110 Modular addition (A+B) mod n Section 24.4.3
0x0F 001111 Modular subtraction (A-B) mod n Section 24.4.4
0x10 010000 Montgomery multiplication (AxB) mod n Section 24.4.5
0x00 000000 Modular exponentiation A
e
mod n
Section 24.4.6
0x02 000010 Modular exponentiation A
e
mod n (fast mode)
0x08 001000 Modular inversion A-1 mod n Section 24.4.7
0x0D 001101 Modular reduction A mod n Section 24.4.8
0x09 001001 Arithmetic addition A+B Section 24.4.9
0x0A 001010 Arithmetic subtraction A-B Section 24.4.10
0x0B 001011 Arithmetic multiplication AxB Section 24.4.11
0x0C 001100 Arithmetic comparison (A=B, A>B, A<B) Section 24.4.12
0x07 000111 RSA CRT exponentiation Section 24.4.13
Table 145. PKA prime field (Fp) elliptic curve functions list
PKA_CR.MODE[5:0]
Performed operation Reference
Hex Binary
0x28 101000 Point on elliptic curve Fp check Section 24.4.14
0x20 100000 ECC scalar multiplication kP
Section 24.4.15
0x22 100010 ECC scalar multiplication kP (fast mode)
0x24 100100 ECDSA sign Section 24.4.16
0x26 100110 ECDSA verification Section 24.4.17
To Next Page
Loading...
Need help?
General
