| BadPaddingException | This exception is thrown when a particular padding mechanism is
 expected for the input data but the data is not padded properly. | 
| Cipher | This class provides the functionality of a cryptographic cipher for
 encryption and decryption. | 
| CipherSpi | This class defines the Service Provider Interface (SPI)
 for the Cipherclass. | 
| ExemptionMechanism | This class provides the functionality of an exemption mechanism, examples
 of which are key recovery, key weakening, and
 key escrow. | 
| ExemptionMechanismException | This is the generic ExemptionMechanism exception. | 
| ExemptionMechanismSpi | This class defines the Service Provider Interface (SPI)
 for the ExemptionMechanismclass. | 
| IllegalBlockSizeException | This exception is thrown when the length of data provided to a block
 cipher is incorrect, i.e., does not match the block size of the cipher. | 
| KeyAgreement | This class provides the functionality of a key agreement (or key
 exchange) protocol. | 
| KeyAgreementSpi | This class defines the Service Provider Interface (SPI)
 for the KeyAgreementclass. | 
| KeyGenerator | This class provides the functionality of a secret (symmetric) key generator. | 
| KeyGeneratorSpi | This class defines the Service Provider Interface (SPI)
 for the KeyGeneratorclass. | 
| Mac | This class provides the functionality of a "Message Authentication Code"
 (MAC) algorithm. | 
| MacSpi | This class defines the Service Provider Interface (SPI)
 for the Macclass. | 
| NoSuchPaddingException | This exception is thrown when a particular padding mechanism is
 requested but is not available in the environment. | 
| SealedObject | This class enables a programmer to create an object and protect its
 confidentiality with a cryptographic algorithm. | 
| SecretKey | A secret (symmetric) key. | 
| SecretKeyFactory | This class represents a factory for secret keys. | 
| SecretKeyFactorySpi | This class defines the Service Provider Interface (SPI)
 for the SecretKeyFactoryclass. | 
| ShortBufferException | This exception is thrown when an output buffer provided by the user
 is too short to hold the operation result. |