1 files changed, 30 insertions, 0 deletions
diff --git a/3544/CH4/EX4.5.3/Ex4_5_3.sce b/3544/CH4/EX4.5.3/Ex4_5_3.sce
new file mode 100644
index 000000000..35d0259ab
--- /dev/null
+++ b/3544/CH4/EX4.5.3/Ex4_5_3.sce
@@ -0,0 +1,30 @@
+
+//ElGamal Key Decryption
+
+// Move scilab to current file directory
+[u,t,n] = file()
+n = strcat(n)
+file_name = basename(n)+fileext(n)
+file_name = strcat(file_name)
+ind=strindex(n,file_name)
+path = part(n,1:ind-1)
+chdir(path)
+
+exec("Chapter_4.sci",-1)
+
+p = 11
+r = 4 
+pt = 7
+d = 3
+e1 = 2
+e2 = modulo(e1^d,p)
+
+c1 = modulo(e1^r,p)
+c2 = modulo(pt*e2^r,p)
+
+x =c1^d
+x_inv = mod_inv(x,p)
+
+pt = modulo(c2*x_inv,p)
+disp("Original plaintext")
+disp(pt)