
318 Chapter 7 • Securing Your Java Code
The important part about encryption is not keeping the algorithm
private. Most algorithms used for encrypting a message are well known,
and explanations are available in literature and on the Internet.The
important part is that it cannot be reversed without knowing the key,
and also that the key is large enough that it is not susceptible to brute
force attacks.With the Roman example of encryption given above,after
we know the encryption algorithm it is quite basic to decrypt the mes-
sage.With DES, knowing the algorithm does not really help to
unscramble a message.To do that we must obtain the key.
There are actually ...