I am developing a program that uses the RSA encryption algorithm to encrypt user input. I currently read the user input into a character array and then run through the array and convert from a letter to a number. I then pad the rest of the array with random numbers. The part I am struggling with is using this array to create a number (all the array elements concatenated) which I will use in the encryption. Any suggestions? I think I could just right the numbers to a file (or maybe the command line) and then read the resulting number back in. This seems somewhat circuitous - is there a faster/easier way?
I am still learning C so maybe I just need to know some special function. Has anyone developed and RSA program?
On a side note, has anyone here done anything with elliptic curve cryptography?