A Hardware-Efficient Elliptic Curve Cryptographic Architecture over GF (p)

Algorithm 2

Modular addition and subtraction in GF(p).

	Input: p, A, B ∈ [0, p − 1]
	Output: R = (A + B) mod p
(1)	C0 = A + B
(2)	C1 = C0 − p
(3)	if C1n = 1 {R = C0}
(4)	else {R = C1}
(5)	return R
	Input: p, A, B ∈ [0, p − 1]
	Output: R = (A − B) mod p
(1)	C0 = A − B
(2)	C1=C0 + p
(3)	if C0 n = 1 {R = C1}
(4)	else {R = C0}
(5)	return R