From d6d0d3c3817b0109d4cccf64f21404946d8b68c9 Mon Sep 17 00:00:00 2001
From: Christoph Fuerst <ch.fuerst@gmx.at>
Date: Thu, 6 Apr 2017 21:32:04 +0200
Subject: [PATCH] Further Pre-Conditions for Discrete Logarithm

---
 discrete_log.txt | 5 ++++-
 1 file changed, 4 insertions(+), 1 deletion(-)

diff --git a/discrete_log.txt b/discrete_log.txt
index 047ffb9..c64a129 100644
--- a/discrete_log.txt
+++ b/discrete_log.txt
@@ -33,7 +33,10 @@ proc InvModP(a:ℕ[K^2],p:prime): prime
 }
 
 proc discrete_log(p:prime,g:nat,a:nat,m:nat): res
-   requires p>1 ∧ isPrime(p) ∧ // p is a prime greater than 1
+   requires 1 < p ∧ isPrime(p) ∧ // p is a prime greater than 1
+            1 < g ∧ g < p ∧ 
+            1 < a ∧ ¬divides(p,a) ∧
+            8 < m ∧ 
             ∀b:nat. (0 < b ∧ b < p-1) ⇒ (g^b % p ≠ 1) ∧  g^(p-1)%p = 1 ∧ // g has order p-1
             0 ≤ a ∧ a < p; // a is in ℤ/pℤ
    ensures (g^result)%p = a;
-- 
2.1.4