1 files changed, 32 insertions, 0 deletions
diff --git a/3544/CH4/EX4.9.1/Ex4_9_1.sce b/3544/CH4/EX4.9.1/Ex4_9_1.sce
new file mode 100644
index 000000000..8c934755d
--- /dev/null
+++ b/3544/CH4/EX4.9.1/Ex4_9_1.sce
@@ -0,0 +1,32 @@
+
+//ElGamal Signature
+
+// 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)
+
+e1 = 10
+e2 = 4
+p = 19
+m = 14      //original message
+d = 16
+r = 5       //random number selected by sender
+
+r_inv = mod_inv(r,p-1)      //inverse of r modulo (p-1)
+
+s1 = modulo(e1^r,p)
+
+temp = (m-d*s1)*r_inv
+while temp<0                    //calculate modulus (p-1) for negative values
+    temp = temp+p-1
+end
+s2 = modulo(temp,p-1)
+
+printf("The signature is: (%d,%d)",s1,s2)