RSA

Encryption Methods/_RSA_ENCRYPTION.py

+#RSA ENCRYPTION
+import random 
+import math
+
+
+def is_prime(number):
+    if number < 2:
+        return False
+    for i in range(2, number // 2 + 1):
+        if number % i == 0:
+            return False
+    return True
+
+
+def generated_prime(limit):
+    n= 1000
+    N = []
+    while True:
+        if n < limit:
+            if is_prime(n):
+                N.append(n)
+            n += 1
+        else:
+            break
+    return N
+
+
+
+def mod_inverse(e, phi):
+    for d in range(3, phi):
+        if (d*e)% phi == 1:
+            return d
+    raise ValueError('mod_inverse invalid')
+
+p, q = random.choice(generated_prime(5000)), random.choice(generated_prime(5000))
+
+while p == q:
+    q = generated_prime(5000)
+
+
+n = p*q
+
+phi_n = (p-1) * (q-1)
+
+e = random.randint(3, phi_n-1)
+while math.gcd(e, phi_n) != 1:
+    e = random.randint(3, phi_n-1)
+
+d = mod_inverse(e, phi_n)
+print('public key is', e)
+print ('private key is', d)
+print("n:",n)
+print("Phie of n:", phi_n)
+print("p:",p)
+print("q:",q)
+
+message = 'hello world'
+
+message_encoded = [ord(c) for c in message]
+#(m^e) mod n =c 
+cipher_text = [pow(c, e ,n) for c in message_encoded]# pow(c, e ,n) ====== > (c^e) mod n
+
+print(cipher_text)
+
+
+message_encoded =[pow (c, d, n) for c in cipher_text]
+message = "".join(chr(c) for c in message_encoded)
+print(message)