echo"<h1> Decodes the ciphered integer using the secret 'd' key : m = c^d mod n. </h1>\n";
//echo "d == $d <p>";
//echo "c == $c <p>";
//echo "digits = $digits<p>";
//echo "\n\n\n\n\n";
//$gt100k = `./gt100k $digits`;
//if ($gt100k != 1)
//echo "<h3>c^d == </h3>";
// check here that the exponentiation can actually be displayed
// and use the recursive algorithms if it cannot
// along with a warning about the length of time it could take.
$digits=`./pow_digits $c $d `;
$gt100_k=`./gt100k $digits`;
//echo "./gt100k $digits";
//echo " gt100_k == $gt100_k";
$date=`date`;
printf("<p> Start Time == %s </p>\n",$date);
if($gt100_k!=1){
echo" <h3> The predicted number of digits from the exponentiation is less than 100,000. </h3></h3>It can therefore be shown in full </h3><p>";
$c_to_d=`echo " $c ^ $d " | bc | sed -f ./nlhtml.sed `;
echo$c_to_d;
`echo " $c ^ $d " | bc | sed -f ./nlhtml.sed `;
echo" % $n <p>";
echo"<h3> this gives the 'in clear' result </h3>";
$clear=`echo " ( $c ^ $d ) % $n " | bc | sed -f ./nlhtml.sed `;
echo$clear;
}
else{
echo"<h3> The number of digits produced by the exponentiation of c^d is greater than 100,0000 </h3>";
echo"<h3> The resursive (see <a href=\"maths.html\"> recursive exponentiation break down </a>) routines will be applied instead to calculate c^d%n </h3>";
$clear=`./cbe.sh 'A $c B $d C $n D'`;// php is very nasty about sending multiple args to scripts
echo"<h3> this gives the 'in clear' result </h3>";
