非对称加密算法是相对于对称加密算法来说的，对于对称加密算法请查阅之前的总结，今天为大家介绍一下DH算法，DH是一种密钥交换算法，接收方根据发送方加密时的密钥，生成接收方解密密钥。下面就一起来学习一下吧：

初始化发送方密钥：

KeyPairGenerator sendKeyPairGenerator = KeyPairGenerator.getInstance("DH");

sendKeyPairGenerator.initialize(512);

KeyPair sendKeyPair = sendKeyPairGenerator.generateKeyPair();

byte[] sendPublicKeyEnc = sendKeyPair.getPublic().getEncoded();//生成发送方公钥，发送给接收方(网络、文件...)

初始化接收方密钥：

KeyFactory receiverKeyFactory = KeyFactory.getInstance("DH");

X509EncodedKeySpec x509EncodedKeySpec = new X509EncodedKeySpec(sendPublicKeyEnc);

PublicKey receivePublicKey = receiverKeyFactory.generatePublic(x509EncodedKeySpec);

DHParameterSpec dhParameterSpec = ((DHPublicKey)receivePublicKey).getParams();

KeyPairGenerator receiverKeyPairGenerator = KeyPairGenerator.getInstance("DH");

receiverKeyPairGenerator.initialize(dhParameterSpec);

KeyPair receiverKeyPair = receiverKeyPairGenerator.generateKeyPair();

PrivateKey receiverPrivateKey = receiverKeyPair.getPrivate();

byte[] receiverPublicKeyEnc = receiverKeyPair.getPublic().getEncoded();

构建接收方密钥：

KeyAgreement receiverKeyAgreement = KeyAgreement.getInstance("DH");

receiverKeyAgreement.init(receiverPrivateKey);

receiverKeyAgreement.doPhase(receivePublicKey, true);

SecretKey receiverDESKey = receiverKeyAgreement.generateSecret("DES");//接收方Key

构建发送方密钥：

KeyFactory sendKeyFactory = KeyFactory.getInstance("DH");

x509EncodedKeySpec = new X509EncodedKeySpec(receiverPublicKeyEnc);

PublicKey sendPublicKey = sendKeyFactory.generatePublic(x509EncodedKeySpec);

KeyAgreement sendKeyAgreement = KeyAgreement.getInstance("DH");

sendKeyAgreement.init(sendKeyPair.getPrivate());

sendKeyAgreement.doPhase(sendPublicKey, true);

SecretKey sendDESKey = sendKeyAgreement.generateSecret("DES");//发送方Key

发送方加密：

Cipher sendCipher = Cipher.getInstance("DES");

sendCipher.init(Cipher.ENCRYPT_MODE, sendDESKey);

byte[] sendResult = sendCipher.doFinal(src.getBytes());

System.out.println("sendResult ："+Hex.encodeHexString(sendResult));

接收方解密：

Cipher receiverCipher = Cipher.getInstance("DES");

receiverCipher.init(Cipher.DECRYPT_MODE, receiverDESKey);

byte[] receiverResult = receiverCipher.doFinal(sendResult);

System.out.println("receiverResult : "+new String (receiverResult));

基于密钥交换的非对称加密算法(DH),到这里就总结完毕了。

以上就是本文的全部内容，希望对大家的学习有所帮助，也希望大家多多支持脚本之家。