Here’s how to encrypt and decrypt a message using CipherOutputStream/
CipherInputStream The methods used are all part of Sun’s JCE (Java Cryptography Extension). Sun’s JCE
documenation is all but useless. You pretty well have to Google the web to find sample code to use these methods
for particular algorithms and block modes.
AES (Advanced Encryption Standard) Encryption
RSA (Rivest, Shamir and Adelman) Public/Private Key Encryption
Requires sender to know public key of receiver, and receiver requires the corresponding private key.
The Javadoc is almost useless. All the methods have undocumented parameters that are specific to various
algorithms. Your best bet is to scour the Internet with Google, e.g. search for PBE DECRYPT_MODE to find Java source code listings where
people used the PBE (Password Based Encryption) algorithm and Cipher. DECRYPT_MODE
to decrypt messages. Beware, much of the code you will find is not working properly. People posted it seeking
help getting it to work. Another source of information is books on JCE.