ModPow/RSA for USBizi

I am currenlty encoding a message with manage modpow (RSA) method on USBizi. The RSA is 1024bit.

The speed is the problem now, it takes about 1900 seconds to do the calulation.

Have someone written a modpow method in native code?

I use BigInteger to hold modulus and exponent.

How are you doing RSA since we have dropped RSA support on USBizi a while back?

In BigInteger class I call modpow with modulus and exponent as input and out I get the message, but performance is not the best.

I have now installed Yagarto package to see if I could make it run under native.

I tried to use the RSA native method that is included for EMX on a Embedded Master Dev board with the latest EMX firmware, but the result is bigger (256 bytes , should be 128) and wrong.

Maybe this will help http://wiki.tinyclr.com/index.php?title=Crypto_AES