From 5fa04509a9c8c5b6980f60eea7435b3ccf221bdd Mon Sep 17 00:00:00 2001
From: Bill Buchanan <w.buchanan@napier.ac.uk>
Date: Fri, 8 Apr 2022 05:56:47 +0100
Subject: [PATCH] Update README.md

---
 unit09_future/lab/README.md | 83 ++++++++++++++++++++++++++++++++++++-
 1 file changed, 82 insertions(+), 1 deletion(-)

diff --git a/unit09_future/lab/README.md b/unit09_future/lab/README.md
index 37ef415..89e3dc0 100644
--- a/unit09_future/lab/README.md
+++ b/unit09_future/lab/README.md
@@ -410,7 +410,88 @@ print 'r=',Result
 if (t==Result):
 	print 'Alice has proven she knows x'
 else:
-	print 'Alice has not proven she knows x'
+	print 'Alice has not proven she knows x'import sys
+import random
+import hashlib
+import libnum
+
+n=997
+
+password="Hello"
+
+g= 3
+
+
+def pickg(p):
+	for x in range (1,p):
+		rand = x
+		exp=1
+		next = rand % p
+
+		while (next != 1 ):
+			next = (next*rand) % p
+			exp = exp+1
+		
+		if (exp==p-1):
+			return rand
+
+v = random.randint(1,n)
+c = random.randint(1,n)
+
+
+if (len(sys.argv)>1):
+	text=str(sys.argv[1])
+
+if (len(sys.argv)>2):
+	v=int(sys.argv[2])
+
+if (len(sys.argv)>3):
+	c=int(sys.argv[3])
+
+if (len(sys.argv)>4):
+	n=int(sys.argv[4])
+
+
+
+print("Password:\t",password)
+x = int(hashlib.md5(password.encode()).hexdigest()[:8], 16) % n
+
+g=pickg(n)
+
+y= pow(g,x,n)
+
+t = pow(g,v,n)
+
+r = (v - c * x) 
+
+if (r<0):
+	Result = ( libnum.invmod(pow(g,-r,n),n) * pow(y,c,n))  % n
+else:
+	Result = ( pow(g,r,n) * pow(y,c,n))  % n
+
+print('\n======Agreed parameters============')
+print('P=',n,'\t(Prime number)')
+print('G=',g,'\t(Generator)')
+
+
+print('\n======The secret==================')
+print('x=',x,'\t(Alice\'s secret)')
+
+print('\n======Random values===============')
+print('c=',c,'\t(Bob\'s random value)')
+print('v=',v,'\t(Alice\'s random value)')
+
+print('\n======Shared value===============')
+print('g^x mod P=\t',y)
+print('r=\t\t',r)
+
+print('\n=========Results===================')
+print('t=g**v % n =\t\t',t)
+print('( (g**r) * (y**c) )=\t',Result)
+if (t==Result):
+	print('Alice has proven she knows password')
+else:
+	print('Alice has not proven she knows x')
 ```
 
 Repl.it: https://repl.it/@billbuchanan/zktut