def decode(self, text, key):
self.decoded_text = ""
self.secret_key_mod_inverse = cu.modular_inverse(
key, self.alphabet_size)
for symbol in text:
index_in_alphabet = self.legal_alphabet.index(symbol)
self.decoded_text += self.legal_alphabet[
(index_in_alphabet * self.secret_key_mod_inverse) %
self.alphabet_size]
return self.decoded_text
def decode(self, text, key):
self.decoded_str = ""
#modular_inverse returnerer modulo-inversen, a = nøkkel, m= lengden av alfabetet
#OBS: En nøkkel n virker bare bare dersom den har en modulo-invers
for character in text:
index = self.legal_alphabet.index(character)
new_key = cu.modular_inverse(key, self.alphabet_size)
self.decoded_str += self.legal_alphabet[(index * new_key) %
self.alphabet_size]
return self.decoded_str
def generate_keys(self):
p = cu.generate_random_prime(8)
q = p
_gcd = 0
while q == p or _gcd != 1:
q = cu.generate_random_prime(8)
p = cu.generate_random_prime(8)
phi = (p - 1) * (q - 1)
e = random.randint(3, phi - 1)
_gcd = gcd(e, phi)
print("p: ", p, "q: ", q, "gcd: ", _gcd)
n = p * q
d = cu.modular_inverse(e, phi)
self.sender_key = (n, e)
self.key = (n, d)
def generate_keys(self, key):
return cu.modular_inverse(key, self.alphabet_size)