Here’s how to encrypt and decrypt a message using CipherOutputStream/ CipherInputStream The
methods used are all part of Oracle’s JCE (Java Cryptography Extension).
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.
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
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.