These are the interfaces for the keys based on the Diffie-Hellman algorithms. The javax.crypto.Cipher engine class forms the core of the JCE 1.2 framework. This class provides the functionality of a cryptographic cipher used for encryption and decryption. This method takes as argument a String object that represents a transformation. These modes are defined as final integer constants in the Cipher class.
Algorithms usually operate on blocks having a predefined size.
Plain text packets, which are of a length not a multiple of that size, must be padded prior to encrypting according to a specified padding scheme. If mode and padding are not specified, provider-specific default values are used. When this happens, it loses all previously acquired states. In other words, initializing a Cipher is equivalent to creating a new instance of that Cipher and initializing it. A multiple-part operation is useful if the exact length of the data is not known in advance, or if the data is too long to be stored in memory all at once.