java.security
Interfaces
| AlgorithmConstraints | This interface specifies constraints for cryptographic algorithms, keys (key sizes), and other algorithm parameters. | 
| Certificate | This is an interface of abstract methods for managing a variety of identity certificates. | 
| DomainCombiner | Legacy security code; do not use. | 
| Guard | This interface represents a guard, which is an object that is used to protect access to another object. | 
| Key | The Key interface is the top-level interface for all keys. | 
| Entry | A marker interface for  | 
| LoadStoreParameter | |
| ProtectionParameter | A marker interface for keystore protection parameters. | 
| Parameters | |
| 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. | 
| PrivilegedAction | Android doesn't support  | 
| PrivilegedExceptionAction | Android doesn't support  | 
| PublicKey | A public key. | 
| SecureRandomParameters | A marker interface for parameters used in various  | 
Classes
| AccessControlContext | Android doesn't support  | 
| AccessController | Android doesn't support  | 
| AlgorithmParameterGenerator | The  | 
| AlgorithmParameterGeneratorSpi | This class defines the Service Provider Interface (SPI) for the  | 
| AlgorithmParameters | This class is used as an opaque representation of cryptographic parameters. | 
| AlgorithmParametersSpi | This class defines the Service Provider Interface (SPI) for the  | 
| AllPermission | Android doesn't support  | 
| AuthProvider | Legacy security code; do not use. | 
| BasicPermission | Android doesn't support  | 
| CodeSigner | This class encapsulates information about a code signer. | 
| CodeSource | Legacy security code; do not use. | 
| DigestInputStream | A transparent stream that updates the associated message digest using the bits going through the stream. | 
| DigestOutputStream | A transparent stream that updates the associated message digest using the bits going through the stream. | 
| DomainLoadStoreParameter | Configuration data that specifies the keystores in a keystore domain. | 
| DrbgParameters | This class specifies the parameters used by a DRBG (Deterministic Random Bit Generator). | 
| GuardedObject | A GuardedObject is an object that is used to protect access to another object. | 
| Identity | This class represents identities: real-world objects such as people, companies or organizations whose identities can be authenticated using their public keys. | 
| IdentityScope | This class represents a scope for identities. | 
| KeyFactory | Key factories are used to convert keys (opaque cryptographic keys of type  | 
| KeyFactorySpi | This class defines the Service Provider Interface (SPI) for the  | 
| 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  | 
| KeyRep | Standardized representation for serialized Key objects. | 
| KeyStore | This class represents a storage facility for cryptographic keys and certificates. | 
| KeyStoreSpi | This class defines the Service Provider Interface (SPI) for the  | 
| 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  | 
| Permission | Android doesn't support  | 
| PermissionCollection | Android doesn't support  | 
| Permissions | Android doesn't support  | 
| PKCS12Attribute | An attribute associated with a PKCS12 keystore entry. | 
| Policy | Android doesn't support  | 
| PolicySpi | This class defines the Service Provider Interface (SPI) for the  | 
| ProtectionDomain | Legacy security code; do not use. | 
| Provider | This class represents a "provider" for the Java Security API, where a provider implements some or all parts of Java Security. | 
| SecureClassLoader | This class extends ClassLoader with additional support for defining classes with an associated code source and permissions which are retrieved by the system policy by default. | 
| SecureRandom | This class provides a cryptographically strong random number generator (RNG). | 
| SecureRandomSpi | This class defines the Service Provider Interface (SPI) for the  | 
| Security | This class centralizes all security properties and common security methods. | 
| SecurityPermission | Legacy security code; do not use. | 
| 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  | 
| SignedObject | SignedObject is a class for the purpose of creating authentic runtime objects whose integrity cannot be compromised without being detected. | 
| Signer | This class is used to represent an Identity that can also digitally sign data. | 
| Timestamp | This class encapsulates information about a signed timestamp. | 
| UnresolvedPermission | Legacy security code; do not use. | 
Exceptions
| AccessControlException | This exception is thrown by the AccessController to indicate that a requested access (to a critical system resource such as the file system or the network) is denied. | 
| DigestException | This is the generic Message Digest exception. | 
| GeneralSecurityException | The  | 
| 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. | 
| PrivilegedActionException | Legacy security code; do not use. | 
| 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. | 
Enums
| CryptoPrimitive | An enumeration of cryptographic primitives. | 
