DigitalSignatureAlgorithm-DSA

• p -> Prime Number 2^L-1 < p < 2^L
• q -> prime divisor of (p-1)
• g -> h^(p-1)q mod p
• h -> any Integer (1 < h < p-1)
• x -> sender private key random number between 0 and q
• y -> public key g^x mod p
• k -> any Integer (0 < k < q)

Signature

• r = (g^k mod p) mod q
• s = [k^-1(Hash(M)+x*r)] mod q

Verifieng

• V = [(g^u1 * y^u2)mod p] mod q
• u1 = [Hash(M) w] mod q
• w = s^-1 mod q
• u2 = r*w mod q

Comparasion

• if r == V -> True

Inputs and Outputs

Inputs

• Sent message
• Recieved message

Outputs

• All variables that calculated above

Requirment

• pip install gmpy2