Java加密算法DES，加密算法des,密钥加密也称为对称加密，

Java加密算法DES，加密算法des,密钥加密也称为对称加密，

密钥加密也称为对称加密，速度快，但加密和解密的钥匙必须相同，只有通信双方才能知道钥匙。```javaimport java.security.Key;
import java.security.SecureRandom;

import javax.crypto.Cipher;
import javax.crypto.KeyGenerator;
import javax.crypto.SecretKey;
import javax.crypto.SecretKeyFactory;
import javax.crypto.spec.DESKeySpec;
import javax.crypto.spec.IvParameterSpec;

/* * DES 算法 1972美国IBM研制，对称加密算法 * @author stone * @date 2014-03-10 04:47:05 /
public class DES {
// 算法名称
public static final String KEY_ALGORITHM = "DES";
// 算法名称/加密模式/填充方式
public static final String CIPHER_ALGORITHM_ECB = "DES/ECB/PKCS5Padding";
public static final String CIPHER_ALGORITHM_CBC = "DES/CBC/PKCS5Padding";

public static void main(String[] args) throws Exception {      /*      * 使用 ECB mode      * 密钥生成器 生成密钥      * ECB mode cannot use IV      */      byte[] key = generateKey();       byte[] encrypt = encrypt("胃炎F#*（x）".getBytes(), key);      System.out.println(new String(decrypt(encrypt, key)));    /*      * 使用CBC mode      * 使用密钥工厂生成密钥，加密 解密      * iv: DES in CBC mode and RSA ciphers with OAEP encoding operation.      */      DESKeySpec dks = new DESKeySpec(generateKey());      SecretKeyFactory factory = SecretKeyFactory.getInstance(KEY_ALGORITHM);      SecretKey secretKey = factory.generateSecret(dks);      Cipher cipher = Cipher.getInstance(CIPHER_ALGORITHM_CBC);      cipher.init(Cipher.ENCRYPT_MODE, secretKey, new IvParameterSpec(getIV()));      byte[] enc = cipher.doFinal("胃炎A%F#*（x）".getBytes()); //加密    cipher.init(Cipher.DECRYPT_MODE, secretKey, new IvParameterSpec(getIV()));      byte[] dec = cipher.doFinal(enc); // 解密      System.out.println(new String(dec));  }static byte[] getIV() {      String iv = "asdfivh7"; //IV length: must be 8 bytes long      return iv.getBytes();  }/**  * 生成密钥  *   * @return  * @throws Exception  */  private static byte[] generateKey() throws Exception {      KeyGenerator keyGenerator = KeyGenerator.getInstance(KEY_ALGORITHM);      keyGenerator.init(56); //des 必须是56, 此初始方法不必须调用      SecretKey secretKey = keyGenerator.generateKey();      return secretKey.getEncoded();  }/**  * 还原密钥  *   * @param key  * @return  * @throws Exception   */  private static Key toKey(byte[] key) throws Exception {      DESKeySpec des = new DESKeySpec(key);      SecretKeyFactory keyFactory = SecretKeyFactory.getInstance(KEY_ALGORITHM);      SecretKey secretKey = keyFactory.generateSecret(des);      return secretKey;  }/**  * 加密   * @param data 原文  * @param key  * @return 密文  * @throws Exception  */  public static byte[] encrypt(byte[] data, byte[] key) throws Exception {      Key k = toKey(key);      Cipher cipher = Cipher.getInstance(CIPHER_ALGORITHM_ECB);      cipher.init(Cipher.ENCRYPT_MODE, k, new SecureRandom());      return cipher.doFinal(data);  }  /**  * 解密  * @param data 密文  * @param key  * @return 明文、原文  * @throws Exception  */  public static byte[] decrypt(byte[] data, byte[] key) throws Exception {      Key k = toKey(key);      Cipher cipher = Cipher.getInstance(CIPHER_ALGORITHM_ECB);      cipher.init(Cipher.DECRYPT_MODE, k, new SecureRandom());      return cipher.doFinal(data);  }

}
```