Java加密技术（五）

关键字: dh, 公钥, 私钥, 非对称加密, 密钥一致协议

    接下来我们分析DH加密算法，一种适基于密钥一致协议的加密算法。
DH
Diffie-Hellman算法(D-H算法)，密钥一致协议。是由公开密钥密码体制的奠基人Diffie和Hellman所提出的一种思想。简单的说就是允许两名用户在公开媒体上交换信息以生成"一致"的、可以共享的密钥。换句话说，就是由甲方产出一对密钥（公钥、私钥），乙方依照甲方公钥产生乙方密钥对（公钥、私钥）。以此为基线，作为数据传输保密基础，同时双方使用同一种对称加密算法构建本地密钥（SecretKey）对数据加密。这样，在互通了本地密钥（SecretKey）算法后，甲乙双方公开自己的公钥，使用对方的公钥和刚才产生的私钥加密数据，同时可以使用对方的公钥和自己的私钥对数据解密。不单单是甲乙双方两方，可以扩展为多方共享数据通讯，这样就完成了网络交互数据的安全通讯！该算法源于中国的同余定理——中国馀数定理。 

流程分析：

1.甲方构建密钥对儿，将公钥公布给乙方，将私钥保留；双方约定数据加密算法；乙方通过甲方公钥构建密钥对儿，将公钥公布给甲方，将私钥保留。
2.甲方使用私钥、乙方公钥、约定数据加密算法构建本地密钥，然后通过本地密钥加密数据，发送给乙方加密后的数据；乙方使用私钥、甲方公钥、约定数据加密算法构建本地密钥，然后通过本地密钥对数据解密。
3.乙方使用私钥、甲方公钥、约定数据加密算法构建本地密钥，然后通过本地密钥加密数据，发送给甲方加密后的数据；甲方使用私钥、乙方公钥、约定数据加密算法构建本地密钥，然后通过本地密钥对数据解密。

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通过java代码实现如下：Coder类见 Java加密技术（一）

Java代码

1. import java.security.Key;   
2. import java.security.KeyFactory;   
3. import java.security.KeyPair;   
4. import java.security.KeyPairGenerator;   
5. import java.security.PublicKey;   
6. import java.security.spec.PKCS8EncodedKeySpec;   
7. import java.security.spec.X509EncodedKeySpec;   
8. import java.util.HashMap;   
9. import java.util.Map;   
10.   
11. import javax.crypto.Cipher;   
12. import javax.crypto.KeyAgreement;   
13. import javax.crypto.SecretKey;   
14. import javax.crypto.interfaces.DHPrivateKey;   
15. import javax.crypto.interfaces.DHPublicKey;   
16. import javax.crypto.spec.DHParameterSpec;   
17.   
18. /**  
19.  * DH安全编码组件  
20.  *   
21.  * @author 梁栋  
22.  * @version 1.0  
23.  * @since 1.0  
24.  */  
25. public abstract class DHCoder extends Coder {   
26.     public static final String ALGORITHM = "DH";   
27.   
28.     /**  
29.      * 默认密钥字节数  
30.      *   
31.      * <pre>  
32.      * DH  
33.      * Default Keysize 1024    
34.      * Keysize must be a multiple of 64, ranging from 512 to 1024 (inclusive).  
35.      * </pre>  
36.      */  
37.     private static final int KEY_SIZE = 1024;   
38.   
39.     /**  
40.      * DH加密下需要一种对称加密算法对数据加密，这里我们使用DES，也可以使用其他对称加密算法。  
41.      */  
42.     public static final String SECRET_ALGORITHM = "DES";   
43.     private static final String PUBLIC_KEY = "DHPublicKey";   
44.     private static final String PRIVATE_KEY = "DHPrivateKey";   
45.   
46.     /**  
47.      * 初始化甲方密钥  
48.      *   
49.      * @return  
50.      * @throws Exception  
51.      */  
52.     public static Map<String, Object> initKey() throws Exception {   
53.         KeyPairGenerator keyPairGenerator = KeyPairGenerator   
54.                 .getInstance(ALGORITHM);   
55.         keyPairGenerator.initialize(KEY_SIZE);   
56.   
57.         KeyPair keyPair = keyPairGenerator.generateKeyPair();   
58.   
59.         // 甲方公钥   
60.         DHPublicKey publicKey = (DHPublicKey) keyPair.getPublic();   
61.   
62.         // 甲方私钥   
63.         DHPrivateKey privateKey = (DHPrivateKey) keyPair.getPrivate();   
64.   
65.         Map<String, Object> keyMap = new HashMap<String, Object>(2);   
66.   
67.         keyMap.put(PUBLIC_KEY, publicKey);   
68.         keyMap.put(PRIVATE_KEY, privateKey);   
69.         return keyMap;   
70.     }   
71.   
72.     /**  
73.      * 初始化乙方密钥  
74.      *   
75.      * @param key  
76.      *            甲方公钥  
77.      * @return  
78.      * @throws Exception  
79.      */  
80.     public static Map<String, Object> initKey(String key) throws Exception {   
81.         // 解析甲方公钥   
82.         byte[] keyBytes = decryptBASE64(key);   
83.         X509EncodedKeySpec x509KeySpec = new X509EncodedKeySpec(keyBytes);   
84.         KeyFactory keyFactory = KeyFactory.getInstance(ALGORITHM);   
85.         PublicKey pubKey = keyFactory.generatePublic(x509KeySpec);   
86.   
87.         // 由甲方公钥构建乙方密钥   
88.         DHParameterSpec dhParamSpec = ((DHPublicKey) pubKey).getParams();   
89.   
90.         KeyPairGenerator keyPairGenerator = KeyPairGenerator   
91.                 .getInstance(keyFactory.getAlgorithm());   
92.         keyPairGenerator.initialize(dhParamSpec);   
93.   
94.         KeyPair keyPair = keyPairGenerator.generateKeyPair();   
95.   
96.         // 乙方公钥   
97.         DHPublicKey publicKey = (DHPublicKey) keyPair.getPublic();   
98.   
99.         // 乙方私钥   
100.         DHPrivateKey privateKey = (DHPrivateKey) keyPair.getPrivate();   
101.   
102.         Map<String, Object> keyMap = new HashMap<String, Object>(2);   
103.   
104.         keyMap.put(PUBLIC_KEY, publicKey);   
105.         keyMap.put(PRIVATE_KEY, privateKey);   
106.   
107.         return keyMap;   
108.     }   
109.   
110.     /**  
111.      * 加密<br>  
112.      *   
113.      * @param data  
114.      *            待加密数据  
115.      * @param publicKey  
116.      *            甲方公钥  
117.      * @param privateKey  
118.      *            乙方私钥  
119.      * @return  
120.      * @throws Exception  
121.      */  
122.     public static byte[] encrypt(byte[] data, String publicKey,   
123.             String privateKey) throws Exception {   
124.   
125.         // 生成本地密钥   
126.         SecretKey secretKey = getSecretKey(publicKey, privateKey);   
127.   
128.         // 数据加密   
129.         Cipher cipher = Cipher.getInstance(secretKey.getAlgorithm());   
130.         cipher.init(Cipher.ENCRYPT_MODE, secretKey);   
131.   
132.         return cipher.doFinal(data);   
133.     }   
134.   
135.     /**  
136.      * 解密<br>  
137.      *   
138.      * @param data  
139.      *            待解密数据  
140.      * @param publicKey  
141.      *            乙方公钥  
142.      * @param privateKey  
143.      *            乙方私钥  
144.      * @return  
145.      * @throws Exception  
146.      */  
147.     public static byte[] decrypt(byte[] data, String publicKey,   
148.             String privateKey) throws Exception {   
149.   
150.         // 生成本地密钥   
151.         SecretKey secretKey = getSecretKey(publicKey, privateKey);   
152.         // 数据解密   
153.         Cipher cipher = Cipher.getInstance(secretKey.getAlgorithm());   
154.         cipher.init(Cipher.DECRYPT_MODE, secretKey);   
155.   
156.         return cipher.doFinal(data);   
157.     }   
158.   
159.     /**  
160.      * 构建密钥  
161.      *   
162.      * @param publicKey  
163.      *            公钥  
164.      * @param privateKey  
165.      *            私钥  
166.      * @return  
167.      * @throws Exception  
168.      */  
169.     private static SecretKey getSecretKey(String publicKey, String privateKey)   
170.             throws Exception {   
171.         // 初始化公钥   
172.         byte[] pubKeyBytes = decryptBASE64(publicKey);   
173.   
174.         KeyFactory keyFactory = KeyFactory.getInstance(ALGORITHM);   
175.         X509EncodedKeySpec x509KeySpec = new X509EncodedKeySpec(pubKeyBytes);   
176.         PublicKey pubKey = keyFactory.generatePublic(x509KeySpec);   
177.   
178.         // 初始化私钥   
179.         byte[] priKeyBytes = decryptBASE64(privateKey);   
180.   
181.         PKCS8EncodedKeySpec pkcs8KeySpec = new PKCS8EncodedKeySpec(priKeyBytes);   
182.         Key priKey = keyFactory.generatePrivate(pkcs8KeySpec);   
183.   
184.         KeyAgreement keyAgree = KeyAgreement.getInstance(keyFactory   
185.                 .getAlgorithm());   
186.         keyAgree.init(priKey);   
187.         keyAgree.doPhase(pubKey, true);   
188.   
189.         // 生成本地密钥   
190.         SecretKey secretKey = keyAgree.generateSecret(SECRET_ALGORITHM);   
191.   
192.         return secretKey;   
193.     }   
194.   
195.     /**  
196.      * 取得私钥  
197.      *   
198.      * @param keyMap  
199.      * @return  
200.      * @throws Exception  
201.      */  
202.     public static String getPrivateKey(Map<String, Object> keyMap)   
203.             throws Exception {   
204.         Key key = (Key) keyMap.get(PRIVATE_KEY);   
205.   
206.         return encryptBASE64(key.getEncoded());   
207.     }   
208.   
209.     /**  
210.      * 取得公钥  
211.      *   
212.      * @param keyMap  
213.      * @return  
214.      * @throws Exception  
215.      */  
216.     public static String getPublicKey(Map<String, Object> keyMap)   
217.             throws Exception {   
218.         Key key = (Key) keyMap.get(PUBLIC_KEY);   
219.   
220.         return encryptBASE64(key.getEncoded());   
221.     }   
222. }  

import java.security.Key;import java.security.KeyFactory;import java.security.KeyPair;import java.security.KeyPairGenerator;import java.security.PublicKey;import java.security.spec.PKCS8EncodedKeySpec;import java.security.spec.X509EncodedKeySpec;import java.util.HashMap;import java.util.Map;import javax.crypto.Cipher;import javax.crypto.KeyAgreement;import javax.crypto.SecretKey;import javax.crypto.interfaces.DHPrivateKey;import javax.crypto.interfaces.DHPublicKey;import javax.crypto.spec.DHParameterSpec;/** * DH安全编码组件 *  * @author 梁栋 * @version 1.0 * @since 1.0 */public abstract class DHCoder extends Coder {public static final String ALGORITHM = "DH";/** * 默认密钥字节数 *  * <pre> * DH * Default Keysize 1024   * Keysize must be a multiple of 64, ranging from 512 to 1024 (inclusive). * </pre> */private static final int KEY_SIZE = 1024;/** * DH加密下需要一种对称加密算法对数据加密，这里我们使用DES，也可以使用其他对称加密算法。 */public static final String SECRET_ALGORITHM = "DES";private static final String PUBLIC_KEY = "DHPublicKey";private static final String PRIVATE_KEY = "DHPrivateKey";/** * 初始化甲方密钥 *  * @return * @throws Exception */public static Map<String, Object> initKey() throws Exception {KeyPairGenerator keyPairGenerator = KeyPairGenerator.getInstance(ALGORITHM);keyPairGenerator.initialize(KEY_SIZE);KeyPair keyPair = keyPairGenerator.generateKeyPair();// 甲方公钥DHPublicKey publicKey = (DHPublicKey) keyPair.getPublic();// 甲方私钥DHPrivateKey privateKey = (DHPrivateKey) keyPair.getPrivate();Map<String, Object> keyMap = new HashMap<String, Object>(2);keyMap.put(PUBLIC_KEY, publicKey);keyMap.put(PRIVATE_KEY, privateKey);return keyMap;}/** * 初始化乙方密钥 *  * @param key *            甲方公钥 * @return * @throws Exception */public static Map<String, Object> initKey(String key) throws Exception {// 解析甲方公钥byte[] keyBytes = decryptBASE64(key);X509EncodedKeySpec x509KeySpec = new X509EncodedKeySpec(keyBytes);KeyFactory keyFactory = KeyFactory.getInstance(ALGORITHM);PublicKey pubKey = keyFactory.generatePublic(x509KeySpec);// 由甲方公钥构建乙方密钥DHParameterSpec dhParamSpec = ((DHPublicKey) pubKey).getParams();KeyPairGenerator keyPairGenerator = KeyPairGenerator.getInstance(keyFactory.getAlgorithm());keyPairGenerator.initialize(dhParamSpec);KeyPair keyPair = keyPairGenerator.generateKeyPair();// 乙方公钥DHPublicKey publicKey = (DHPublicKey) keyPair.getPublic();// 乙方私钥DHPrivateKey privateKey = (DHPrivateKey) keyPair.getPrivate();Map<String, Object> keyMap = new HashMap<String, Object>(2);keyMap.put(PUBLIC_KEY, publicKey);keyMap.put(PRIVATE_KEY, privateKey);return keyMap;}/** * 加密<br> *  * @param data *            待加密数据 * @param publicKey *            甲方公钥 * @param privateKey *            乙方私钥 * @return * @throws Exception */public static byte[] encrypt(byte[] data, String publicKey,String privateKey) throws Exception {// 生成本地密钥SecretKey secretKey = getSecretKey(publicKey, privateKey);// 数据加密Cipher cipher = Cipher.getInstance(secretKey.getAlgorithm());cipher.init(Cipher.ENCRYPT_MODE, secretKey);return cipher.doFinal(data);}/** * 解密<br> *  * @param data *            待解密数据 * @param publicKey *            乙方公钥 * @param privateKey *            乙方私钥 * @return * @throws Exception */public static byte[] decrypt(byte[] data, String publicKey,String privateKey) throws Exception {// 生成本地密钥SecretKey secretKey = getSecretKey(publicKey, privateKey);// 数据解密Cipher cipher = Cipher.getInstance(secretKey.getAlgorithm());cipher.init(Cipher.DECRYPT_MODE, secretKey);return cipher.doFinal(data);}/** * 构建密钥 *  * @param publicKey *            公钥 * @param privateKey *            私钥 * @return * @throws Exception */private static SecretKey getSecretKey(String publicKey, String privateKey)throws Exception {// 初始化公钥byte[] pubKeyBytes = decryptBASE64(publicKey);KeyFactory keyFactory = KeyFactory.getInstance(ALGORITHM);X509EncodedKeySpec x509KeySpec = new X509EncodedKeySpec(pubKeyBytes);PublicKey pubKey = keyFactory.generatePublic(x509KeySpec);// 初始化私钥byte[] priKeyBytes = decryptBASE64(privateKey);PKCS8EncodedKeySpec pkcs8KeySpec = new PKCS8EncodedKeySpec(priKeyBytes);Key priKey = keyFactory.generatePrivate(pkcs8KeySpec);KeyAgreement keyAgree = KeyAgreement.getInstance(keyFactory.getAlgorithm());keyAgree.init(priKey);keyAgree.doPhase(pubKey, true);// 生成本地密钥SecretKey secretKey = keyAgree.generateSecret(SECRET_ALGORITHM);return secretKey;}/** * 取得私钥 *  * @param keyMap * @return * @throws Exception */public static String getPrivateKey(Map<String, Object> keyMap)throws Exception {Key key = (Key) keyMap.get(PRIVATE_KEY);return encryptBASE64(key.getEncoded());}/** * 取得公钥 *  * @param keyMap * @return * @throws Exception */public static String getPublicKey(Map<String, Object> keyMap)throws Exception {Key key = (Key) keyMap.get(PUBLIC_KEY);return encryptBASE64(key.getEncoded());}}

再给出一个测试类：

Java代码

1. import static org.junit.Assert.*;   
2.   
3. import java.util.Map;   
4.   
5. import org.junit.Test;   
6.   
7. /**  
8.  *   
9.  * @author 梁栋  
10.  * @version 1.0  
11.  * @since 1.0  
12.  */  
13. public class DHCoderTest {   
14.   
15.     @Test  
16.     public void test() throws Exception {   
17.         // 生成甲方密钥对儿   
18.         Map<String, Object> aKeyMap = DHCoder.initKey();   
19.         String aPublicKey = DHCoder.getPublicKey(aKeyMap);   
20.         String aPrivateKey = DHCoder.getPrivateKey(aKeyMap);   
21.   
22.         System.err.println("甲方公钥:/r" + aPublicKey);   
23.         System.err.println("甲方私钥:/r" + aPrivateKey);   
24.            
25.         // 由甲方公钥产生本地密钥对儿   
26.         Map<String, Object> bKeyMap = DHCoder.initKey(aPublicKey);   
27.         String bPublicKey = DHCoder.getPublicKey(bKeyMap);   
28.         String bPrivateKey = DHCoder.getPrivateKey(bKeyMap);   
29.            
30.         System.err.println("乙方公钥:/r" + bPublicKey);   
31.         System.err.println("乙方私钥:/r" + bPrivateKey);   
32.            
33.         String aInput = "abc ";   
34.         System.err.println("原文: " + aInput);   
35.   
36.         // 由甲方公钥，乙方私钥构建密文   
37.         byte[] aCode = DHCoder.encrypt(aInput.getBytes(), aPublicKey,   
38.                 bPrivateKey);   
39.   
40.         // 由乙方公钥，甲方私钥解密   
41.         byte[] aDecode = DHCoder.decrypt(aCode, bPublicKey, aPrivateKey);   
42.         String aOutput = (new String(aDecode));   
43.   
44.         System.err.println("解密: " + aOutput);   
45.   
46.         assertEquals(aInput, aOutput);   
47.   
48.         System.err.println(" ===============反过来加密解密================== ");   
49.         String bInput = "def ";   
50.         System.err.println("原文: " + bInput);   
51.   
52.         // 由乙方公钥，甲方私钥构建密文   
53.         byte[] bCode = DHCoder.encrypt(bInput.getBytes(), bPublicKey,   
54.                 aPrivateKey);   
55.   
56.         // 由甲方公钥，乙方私钥解密   
57.         byte[] bDecode = DHCoder.decrypt(bCode, aPublicKey, bPrivateKey);   
58.         String bOutput = (new String(bDecode));   
59.   
60.         System.err.println("解密: " + bOutput);   
61.   
62.         assertEquals(bInput, bOutput);   
63.     }   
64.   
65. }  

import static org.junit.Assert.*;import java.util.Map;import org.junit.Test;/** *  * @author 梁栋 * @version 1.0 * @since 1.0 */public class DHCoderTest {@Testpublic void test() throws Exception {// 生成甲方密钥对儿Map<String, Object> aKeyMap = DHCoder.initKey();String aPublicKey = DHCoder.getPublicKey(aKeyMap);String aPrivateKey = DHCoder.getPrivateKey(aKeyMap);System.err.println("甲方公钥:/r" + aPublicKey);System.err.println("甲方私钥:/r" + aPrivateKey);// 由甲方公钥产生本地密钥对儿Map<String, Object> bKeyMap = DHCoder.initKey(aPublicKey);String bPublicKey = DHCoder.getPublicKey(bKeyMap);String bPrivateKey = DHCoder.getPrivateKey(bKeyMap);System.err.println("乙方公钥:/r" + bPublicKey);System.err.println("乙方私钥:/r" + bPrivateKey);String aInput = "abc ";System.err.println("原文: " + aInput);// 由甲方公钥，乙方私钥构建密文byte[] aCode = DHCoder.encrypt(aInput.getBytes(), aPublicKey,bPrivateKey);// 由乙方公钥，甲方私钥解密byte[] aDecode = DHCoder.decrypt(aCode, bPublicKey, aPrivateKey);String aOutput = (new String(aDecode));System.err.println("解密: " + aOutput);assertEquals(aInput, aOutput);System.err.println(" ===============反过来加密解密================== ");String bInput = "def ";System.err.println("原文: " + bInput);// 由乙方公钥，甲方私钥构建密文byte[] bCode = DHCoder.encrypt(bInput.getBytes(), bPublicKey,aPrivateKey);// 由甲方公钥，乙方私钥解密byte[] bDecode = DHCoder.decrypt(bCode, aPublicKey, bPrivateKey);String bOutput = (new String(bDecode));System.err.println("解密: " + bOutput);assertEquals(bInput, bOutput);}}

控制台输出：

Console代码

1. 甲方公钥:   
2. MIHfMIGXBgkqhkiG9w0BAwEwgYkCQQD8poLOjhLKuibvzPcRDlJtsHiwXt7LzR60ogjzrhYXrgHz   
3. W5Gkfm32NBPF4S7QiZvNEyrNUNmRUb3EPuc3WS4XAkBnhHGyepz0TukaScUUfbGpqvJE8FpDTWSG   
4. kx0tFCcbnjUDC3H9c9oXkGmzLik1Yw4cIGI1TQ2iCmxBblC+eUykAgIBgANDAAJAdAWBVmIzqcko   
5. Ej6qFjLDL2+Y3FPq1iRbnOyOpDj71yKaK1K+FhTv04B0zy4DKcvAASV7/Gv0W+bgqdmffRkqrQ==   
6.   
7. 甲方私钥:   
8. MIHRAgEAMIGXBgkqhkiG9w0BAwEwgYkCQQD8poLOjhLKuibvzPcRDlJtsHiwXt7LzR60ogjzrhYX   
9. rgHzW5Gkfm32NBPF4S7QiZvNEyrNUNmRUb3EPuc3WS4XAkBnhHGyepz0TukaScUUfbGpqvJE8FpD   
10. TWSGkx0tFCcbnjUDC3H9c9oXkGmzLik1Yw4cIGI1TQ2iCmxBblC+eUykAgIBgAQyAjACJRfy1LyR   
11. eHyD+4Hfb+xR0uoIGR1oL9i9Nk6g2AAuaDPgEVWHn+QXID13yL/uDos=   
12.   
13. 乙方公钥:   
14. MIHfMIGXBgkqhkiG9w0BAwEwgYkCQQD8poLOjhLKuibvzPcRDlJtsHiwXt7LzR60ogjzrhYXrgHz   
15. W5Gkfm32NBPF4S7QiZvNEyrNUNmRUb3EPuc3WS4XAkBnhHGyepz0TukaScUUfbGpqvJE8FpDTWSG   
16. kx0tFCcbnjUDC3H9c9oXkGmzLik1Yw4cIGI1TQ2iCmxBblC+eUykAgIBgANDAAJAVEYSfBA+I9nr   
17. dWw3OBv475C+eBrWBBYqt0m6/eu4ptuDQHwV4MmUtKAC2wc2nNrdb1wmBhY1X8RnWkJ1XmdDbQ==   
18.   
19. 乙方私钥:   
20. MIHSAgEAMIGXBgkqhkiG9w0BAwEwgYkCQQD8poLOjhLKuibvzPcRDlJtsHiwXt7LzR60ogjzrhYX   
21. rgHzW5Gkfm32NBPF4S7QiZvNEyrNUNmRUb3EPuc3WS4XAkBnhHGyepz0TukaScUUfbGpqvJE8FpD   
22. TWSGkx0tFCcbnjUDC3H9c9oXkGmzLik1Yw4cIGI1TQ2iCmxBblC+eUykAgIBgAQzAjEAqaZiCdXp   
23. 2iNpdBlHRaO9ir70wo2n32xNlIzIX19VLSPCDdeUWkgRv4CEj/8k+/yd   
24.   
25. 原文: abc    
26. 解密: abc    
27.  ===============反过来加密解密==================    
28. 原文: def    
29. 解密: def   

甲方公钥:MIHfMIGXBgkqhkiG9w0BAwEwgYkCQQD8poLOjhLKuibvzPcRDlJtsHiwXt7LzR60ogjzrhYXrgHzW5Gkfm32NBPF4S7QiZvNEyrNUNmRUb3EPuc3WS4XAkBnhHGyepz0TukaScUUfbGpqvJE8FpDTWSGkx0tFCcbnjUDC3H9c9oXkGmzLik1Yw4cIGI1TQ2iCmxBblC+eUykAgIBgANDAAJAdAWBVmIzqckoEj6qFjLDL2+Y3FPq1iRbnOyOpDj71yKaK1K+FhTv04B0zy4DKcvAASV7/Gv0W+bgqdmffRkqrQ==甲方私钥:MIHRAgEAMIGXBgkqhkiG9w0BAwEwgYkCQQD8poLOjhLKuibvzPcRDlJtsHiwXt7LzR60ogjzrhYXrgHzW5Gkfm32NBPF4S7QiZvNEyrNUNmRUb3EPuc3WS4XAkBnhHGyepz0TukaScUUfbGpqvJE8FpDTWSGkx0tFCcbnjUDC3H9c9oXkGmzLik1Yw4cIGI1TQ2iCmxBblC+eUykAgIBgAQyAjACJRfy1LyReHyD+4Hfb+xR0uoIGR1oL9i9Nk6g2AAuaDPgEVWHn+QXID13yL/uDos=乙方公钥:MIHfMIGXBgkqhkiG9w0BAwEwgYkCQQD8poLOjhLKuibvzPcRDlJtsHiwXt7LzR60ogjzrhYXrgHzW5Gkfm32NBPF4S7QiZvNEyrNUNmRUb3EPuc3WS4XAkBnhHGyepz0TukaScUUfbGpqvJE8FpDTWSGkx0tFCcbnjUDC3H9c9oXkGmzLik1Yw4cIGI1TQ2iCmxBblC+eUykAgIBgANDAAJAVEYSfBA+I9nrdWw3OBv475C+eBrWBBYqt0m6/eu4ptuDQHwV4MmUtKAC2wc2nNrdb1wmBhY1X8RnWkJ1XmdDbQ==乙方私钥:MIHSAgEAMIGXBgkqhkiG9w0BAwEwgYkCQQD8poLOjhLKuibvzPcRDlJtsHiwXt7LzR60ogjzrhYXrgHzW5Gkfm32NBPF4S7QiZvNEyrNUNmRUb3EPuc3WS4XAkBnhHGyepz0TukaScUUfbGpqvJE8FpDTWSGkx0tFCcbnjUDC3H9c9oXkGmzLik1Yw4cIGI1TQ2iCmxBblC+eUykAgIBgAQzAjEAqaZiCdXp2iNpdBlHRaO9ir70wo2n32xNlIzIX19VLSPCDdeUWkgRv4CEj/8k+/yd原文: abc 解密: abc  ===============反过来加密解密================== 原文: def 解密: def 

如我所言，甲乙双方在获得对方公钥后可以对发送给对方的数据加密，同时也能对接收到的数据解密，达到了数据安全通信的目的！


相关链接：
Java加密技术（一）
Java加密技术（二）
Java加密技术（三）
Java加密技术（四）
Java加密技术（五）
Java加密技术（六）
Java加密技术（七）
Java加密技术（八）
Java加密技术（九）
Java加密技术（十）