Returns the standard algorithm name for this key. For example, "DSA" would indicate that this key is a DSA key. See Appendix A in the <a href= "../../../technotes/guides/security/crypto/CryptoSpec.html#AppA"> Java Cryptography Architecture API Specification & Reference </a> for information about standard algorithm names.
Returns the key in its primary encoding format, or null if this key does not support encoding.
Returns the name of the primary encoding format of this key, or null if this key does not support encoding. The primary encoding format is named in terms of the appropriate ASN.1 data format, if an ASN.1 specification for this key exists. For example, the name of the ASN.1 data format for public keys is <I>SubjectPublicKeyInfo</I>, as defined by the X.509 standard; in this case, the returned format is {@code "X.509"}. Similarly, the name of the ASN.1 data format for private keys is <I>PrivateKeyInfo</I>, as defined by the PKCS #8 standard; in this case, the returned format is {@code "PKCS#8"}.
The Key interface is the top-level interface for all keys. It defines the functionality shared by all key objects. All keys have three characteristics:
<UL>
<LI>An Algorithm
<P>This is the key algorithm for that key. The key algorithm is usually an encryption or asymmetric operation algorithm (such as DSA or RSA), which will work with those algorithms and with related algorithms (such as MD5 with RSA, SHA-1 with RSA, Raw DSA, etc.) The name of the algorithm of a key is obtained using the {@link #getAlgorithm() getAlgorithm} method.
<LI>An Encoded Form
<P>This is an external encoded form for the key used when a standard representation of the key is needed outside the Java Virtual Machine, as when transmitting the key to some other party. The key is encoded according to a standard format (such as X.509 {@code SubjectPublicKeyInfo} or PKCS#8), and is returned using the {@link #getEncoded() getEncoded} method. Note: The syntax of the ASN.1 type {@code SubjectPublicKeyInfo} is defined as follows:
<pre> SubjectPublicKeyInfo ::= SEQUENCE { algorithm AlgorithmIdentifier, subjectPublicKey BIT STRING }
AlgorithmIdentifier ::= SEQUENCE { algorithm OBJECT IDENTIFIER, parameters ANY DEFINED BY algorithm OPTIONAL } </pre>
For more information, see <a href="http://www.ietf.org/rfc/rfc3280.txt">RFC 3280: Internet X.509 Public Key Infrastructure Certificate and CRL Profile</a>.
<LI>A Format
<P>This is the name of the format of the encoded key. It is returned by the {@link #getFormat() getFormat} method.
</UL>
Keys are generally obtained through key generators, certificates, or various Identity classes used to manage keys. Keys may also be obtained from key specifications (transparent representations of the underlying key material) through the use of a key factory (see {@link KeyFactory}).
<p> A Key should use KeyRep as its serialized representation. Note that a serialized Key may contain sensitive information which should not be exposed in untrusted environments. See the <a href="../../../platform/serialization/spec/security.html"> Security Appendix</a> of the Serialization Specification for more information.
@see PublicKey @see PrivateKey @see KeyPair @see KeyPairGenerator @see KeyFactory @see KeyRep @see java.security.spec.KeySpec @see Identity @see Signer
@author Benjamin Renaud