See: Description
| Interface | Description | 
|---|---|
| Guard | This interface is only defined for hierarchy compatibility. | 
| Key | The Key interface is the top-level interface for all keys. | 
| Principal | This interface represents the abstract notion of a principal, which can be used to represent any entity, such as an
 individual, a corporation, and a login id. | 
| PrivateKey | A private key. | 
| PublicKey | 
 A public key. | 
| Class | Description | 
|---|---|
| BasicPermission | The BasicPermission class extends the Permission class, and can be used as the base class for
 permissions that want to follow the same naming convention as BasicPermission. | 
| KeyFactory | Key factories are used to convert keys (opaque cryptographic keys of type  Key) into key
 specifications (transparent representations of the underlying key material), and vice versa. | 
| KeyPair | This class is a simple holder for a key pair (a public key and a private key). | 
| KeyPairGenerator | The KeyPairGenerator class is used to generate pairs of public and private keys. | 
| KeyPairGeneratorSpi | 
 This class defines the Service Provider Interface (SPI) for the  KeyPairGeneratorclass, which
 is used to generate pairs of public and private keys. | 
| KeyStore | This class represents a storage facility for cryptographic keys and certificates. | 
| KeyStoreSpi | This class defines the Service Provider Interface (SPI) for the  KeyStoreclass. | 
| MessageDigest | This MessageDigest class provides applications the functionality of a message digest algorithm, such as SHA-1 or
 SHA-256. | 
| MessageDigestSpi | This class defines the Service Provider Interface (SPI) for the  MessageDigestclass, which
 provides the functionality of a message digest algorithm, such as MD5 or SHA. | 
| Permission | Abstract class for representing access to a system resource. | 
| SecureRandom | This class provides a cryptographically strong random number generator (RNG). | 
| SecurityPermission | This class is for security permissions. | 
| Signature | The Signature class is used to provide applications the functionality of a digital signature algorithm. | 
| SignatureSpi | This class defines the Service Provider Interface (SPI) for the  Signatureclass, which is used
 to provide the functionality of a digital signature algorithm. | 
| Exception | Description | 
|---|---|
| DigestException | This is the generic Message Digest exception. | 
| GeneralSecurityException | The  GeneralSecurityExceptionclass is a generic security exception class that provides type safety for all
 the security-related exception classes that extend from it. | 
| InvalidAlgorithmParameterException | This is the exception for invalid or inappropriate algorithm parameters. | 
| InvalidKeyException | This is the exception for invalid Keys (invalid encoding, wrong length, uninitialized, etc). | 
| InvalidParameterException | This exception, designed for use by the JCA/JCE engine classes, is thrown when an invalid parameter is passed to a
 method. | 
| KeyException | This is the basic key exception. | 
| KeyManagementException | This is the general key management exception for all operations dealing with key management. | 
| KeyStoreException | This is the generic KeyStore exception. | 
| NoSuchAlgorithmException | This exception is thrown when a particular cryptographic algorithm is requested but is not available in the
 environment. | 
| NoSuchProviderException | This exception is thrown when a particular security provider is requested but is not available in the environment. | 
| ProviderException | A runtime exception for Provider exceptions (such as misconfiguration errors or unrecoverable internal errors), which
 may be subclassed by Providers to throw specialized, provider-specific runtime errors. | 
| SignatureException | This is the generic Signature exception. | 
| UnrecoverableEntryException | This exception is thrown if an entry in the keystore cannot be recovered. | 
| UnrecoverableKeyException | This exception is thrown if a key in the keystore cannot be recovered. |