A.8 Encrypting a Bytestream

Another way of protecting a bytestream outside the virtual machine is to encrypt the stream produced by the serialization package. Encrypting the bytestream prevents the decoding and the reading of a serialized object's private state, and can help safeguard against tampering with stream contents.

Object serialization allows encryption, both by allowing classes to define their own methods for serialization and deserialization (inside which encryption can be used), and by adhering to the composable stream abstraction (allowing the output of a serialization stream to be channelled into another filter stream which encrypts the data).