RSA algorithm?

Discussion in 'Computing and Networks' started by Mathematics!, Jan 2, 2011.

  1. Mathematics!

    Thread Starter Senior Member

    Jul 21, 2008
    I know how to implement this algorithm but what I don't get is say
    I have a message

    Hello this is a secret message!

    Before the algorithm is used you must have to translate these characters/spaces to some number. And once you have this number you can encrypt by finding 2 big primes p , q then decrypting is just finding d the inverse of e and raising the encrypted message to that power ,...etc.

    I am most curious how they translate the message to/from a number.
    I am assuming they just use ascii...but not sure if their using something else.

    Curious if anybody knows.
    Last edited: Jan 2, 2011
  2. bertus


    Apr 5, 2008
  3. Mathematics!

    Thread Starter Senior Member

    Jul 21, 2008
    Thanks got it.

    Curious, though the RSA algorithm depends on not being able to determine
    d. Which is secure only to the extend that you cann't factor n = p*q.
    Normally n is almost impossible to factor in reasonable time.

    But d can be obtained by knowning eulersphi(n).

    My question is is their an easy way to find eulersphi(n) from n. If eulersphi(n) is not NP hard as prime factorization is thought to be. Then the algorithm would depend on eulersphi(n). (and if their was an easy way to find eulersphi then the whole RSA algorithm would be in jeopardy )

    So either knowning p , q or knowing eulersphi(n) would crack the private key.

    Anybody know if eulersphi(n) is NP hard or at least as hard as factorization?

    Last edited: Jan 3, 2011