Java Cryptography

Name

Class javax.crypto.Cipher

Description

This class represents a cryptographic cipher, either symmetric or asymmetric. To get a cipher for a particular algorithm, call one of the getInstance() methods. You should specify an algorithm name, a cipher mode, and a padding scheme. The cipher should be initialized for encryption or decryption using the init() method and an appropriate key. To actually perform the encryption or decryption, use update() and doFinal(). The following example shows how to encrypt plaintext using a DES cipher in ECB mode with PKCS#5 padding:

public byte[] simpleEncrypt(byte[] plaintext, Key key) throws Exception 
{
  Cipher cipher = Cipher.getInstance("DES/ECB/PKCS5Padding");
  cipher.init(Cipher.ENCRYPT_MODE, key);
  byte[] ciphertext = cipher.doFinal(stringBytes);
  return ciphertext;
}

Class Definition

public class javax.crypto.Cipher
  extends java.lang.Object {

  // Constants
  public static final int DECRYPT_MODE;
  public static final int ENCRYPT_MODE;

  // Constructors
  protected Cipher(CipherSpi, Provider, String);

  // Class Methods
  public static final Cipher getInstance(String);
  public static final Cipher getInstance(String, String);

  // Instance Methods
  public final byte[] doFinal();
  public final byte[] doFinal(byte[]);
  public final int doFinal(byte[], int);
  public final byte[] doFinal(byte[], int, int);

public final int doFinal(byte[], int, int, byte[]); public final int doFinal(byte[], int, int, byte[], int); public final int getBlockSize(); public final byte[] getIV(); ...