
SymmetricEncryption |
ptolemy.actor.lib.security.SymmetricEncryption |
Encrypt an unsigned byte array using a symmetric algorithm.
<p>In cryptography, a symmetric algorithm is an algorithm that uses
the same key for encryption and decryption. An asymmetric algorithm uses
two different keys: a public key and a private key. Sun's documentation
says that asymmetric algorithms are usually much slower than
symmetric algorithms. The initial default set of algorithms that
comes with the Sun JDK does not include an asymmetric encryption algorithm,
though other algorithms may be installed by the system administrator.
<p>This actor reads an unsigned byte array at the <i>input</i> port,
encrypts the data using the data from the <i>key</i> port and then
writes the unsigned byte array results to the <i>output</i> port.
<p>The <i>key</i> should be the same for both the
SymmetricDecryption actor and this actor. The <i>key</i> should not
be visible to users as the security of the encrypted message relies on
the secrecy of this key.
<p>The <i>algorithm</i> parameter determines which algorithm is used.
The algorithm specified must be symmetric. The mode and padding can also
be specified in the <i>mode</i> and <i>padding</i> parameters. In
case a provider specific instance of an algorithm is needed the
provider may also be specified in the <i>provider</i> parameter.
<p>Note that for simplicity, this actor does not support the
notion of algorithm parameters, so the algorithm must not require
that algorithm parameters be transmitted separately from the key.
If the user selects an algorithm that uses algorithm parameters, then
an exception will likely be thrown.
<p>This actor relies on the Java Cryptography Architecture (JCA) and Java
Cryptography Extension (JCE). See the
<a href="../../../../ptolemy/actor/lib/security/CryptographyActor.xml">ptolemy.actor.lib.security.CryptographyActor</a> documentation for
resources about the JCE.
Author(s): Christopher Hylands Brooks, Contributor: Rakesh Reddy
Version:$Id: SymmetricEncryption.doc.html,v 1.1 2006/02/22 18:42:26 mangal Exp $
Pt.Proposed Rating:Green (cxh)
Pt.Accepted Rating:Yellow (cxh)
key
The key to be used by this actor to encrypt the data.
The type is an KeyToken containing a java.security.Key.
Usually the output of the <a href="../../../../ptolemy/actor/lib/security/SecretKey.xml">ptolemy.actor.lib.security.SecretKey</a>
actor is connected to this port