Algorithm for RSA

mayank-khattar · web-flow · commit 4ce8ed90005b · 2020-10-01T14:15:52.000+05:30
RSA algorithm is asymmetric cryptography algorithm. Asymmetric actually means that it works on two different keys i.e. Public Key and Private Key. As the name describes that the Public Key is given to everyone and Private key is kept private.
diff --git a/RSA_algorithm.py b/RSA_algorithm.py
@@ -0,0 +1,32 @@
+from decimal import Decimal 
+  
+def gcd(a,b): 
+    if b==0: 
+        return a 
+    else: 
+        return gcd(b,a%b) 
+p = int(input('Enter the value of p = ')) 
+q = int(input('Enter the value of q = ')) 
+no = int(input('Enter the value of text = ')) 
+n = p*q 
+t = (p-1)*(q-1) 
+  
+for e in range(2,t): 
+    if gcd(e,t)== 1: 
+        break
+  
+  
+for i in range(1,10): 
+    x = 1 + i*t 
+    if x % e == 0: 
+        d = int(x/e) 
+        break
+ctt = Decimal(0) 
+ctt =pow(no,e) 
+ct = ctt % n 
+  
+dtt = Decimal(0) 
+dtt = pow(ct,d) 
+dt = dtt % n 
+  
+print('n = '+str(n)+' e = '+str(e)+' t = '+str(t)+' d = '+str(d)+' cipher text = '+str(ct)+' decrypted text = '+str(dt)) 
