COMPSCI 469 Computer Security Assignment3

This assignment is designed to implement the RSA using big integer package.

It is required to use Java to write the program. (You may choose C/C++.)

For Java, the packages java.math.BigInteger and java.security.SecureRandom should be used. (For C/C++, you may use GMP, the GNU Multiple Precision Arithmetic Library, for handling big numbers. GMP manual can be found at http://www.swox.com/gmp/. Your program should be compiled using gcc/g++.)

Source code should be well commented.

The prime numbers p and q should be at least 1536 bits.

The (absolute value of the) difference of two primes should be bigger than 21000 .

A demonstration of encrypting a message (big number) and decrypting the ciphertext (big number) should be given. You should check that your message is coprime to the modulus N = pq.

Your program should also include the encryption and decryption timing. The encryption/decryption time should be bigger than zero.

The public key component e must be 65537.

Your program should be compilable using command line javac.