Java中的数据加密与解密技术
大家好，我是微赚淘客系统3.0的小编，是个冬天不穿秋裤，天冷也要风度的程序猿！今天我们来探讨Java中的数据加密与解密技术。
一、数据加密与解密的基本概念
数据加密与解密是保护敏感信息的重要手段，通过将明文数据转换为密文，防止未经授权的访问。在Java中，我们常用的加密算法包括对称加密算法（如AES）和非对称加密算法（如RSA）。对称加密使用相同的密钥进行加密和解密，而非对称加密使用一对密钥（公钥和私钥）进行加密和解密。
二、对称加密算法：AES
AES（Advanced Encryption Standard）是一种常见的对称加密算法。以下是使用AES进行加密和解密的示例代码：
package cn.juwatech.encryption;
import javax.crypto.Cipher;
import javax.crypto.KeyGenerator;
import javax.crypto.SecretKey;
import javax.crypto.spec.SecretKeySpec;
import java.util.Base64;
public class AesEncryption {
private static final String ALGORITHM = "AES";
// 生成AES密钥
public static SecretKey generateKey() throws Exception {
KeyGenerator keyGen = KeyGenerator.getInstance(ALGORITHM);
keyGen.init(256); // 可以选择128, 192, 256位的密钥
return keyGen.generateKey();
}
// 加密
public static String encrypt(String data, SecretKey key) throws Exception {
Cipher cipher = Cipher.getInstance(ALGORITHM);
cipher.init(Cipher.ENCRYPT_MODE, key);
byte[] encryptedData = cipher.doFinal(data.getBytes());
return Base64.getEncoder().encodeToString(encryptedData);
}
// 解密
public static String decrypt(String encryptedData, SecretKey key) throws Exception {
Cipher cipher = Cipher.getInstance(ALGORITHM);
cipher.init(Cipher.DECRYPT_MODE, key);
byte[] decodedData = Base64.getDecoder().decode(encryptedData);
byte[] decryptedData = cipher.doFinal(decodedData);
return new String(decryptedData);
}
public static void main(String[] args) {
try {
String data = "Hello, World!";
SecretKey key = generateKey();
String encryptedData = encrypt(data, key);
System.out.println("Encrypted Data: " + encryptedData);
String decryptedData = decrypt(encryptedData, key);
System.out.println("Decrypted Data: " + decryptedData);
} catch (Exception e) {
e.printStackTrace();
}
}
}
三、非对称加密算法：RSA
RSA（Rivest–Shamir–Adleman）是一种常见的非对称加密算法。以下是使用RSA进行加密和解密的示例代码：
package cn.juwatech.encryption;
import javax.crypto.Cipher;
import java.security.*;
import java.util.Base64;
public class RsaEncryption {
private static final String ALGORITHM = "RSA";
// 生成RSA密钥对
public static KeyPair generateKeyPair() throws Exception {
KeyPairGenerator keyGen = KeyPairGenerator.getInstance(ALGORITHM);
keyGen.initialize(2048);
return keyGen.generateKeyPair();
}
// 加密
public static String encrypt(String data, PublicKey publicKey) throws Exception {
Cipher cipher = Cipher.getInstance(ALGORITHM);
cipher.init(Cipher.ENCRYPT_MODE, publicKey);
byte[] encryptedData = cipher.doFinal(data.getBytes());
return Base64.getEncoder().encodeToString(encryptedData);
}
// 解密
public static String decrypt(String encryptedData, PrivateKey privateKey) throws Exception {
Cipher cipher = Cipher.getInstance(ALGORITHM);
cipher.init(Cipher.DECRYPT_MODE, privateKey);
byte[] decodedData = Base64.getDecoder().decode(encryptedData);
byte[] decryptedData = cipher.doFinal(decodedData);
return new String(decryptedData);
}
public static void main(String[] args) {
try {
String data = "Hello, World!";
KeyPair keyPair = generateKeyPair();
String encryptedData = encrypt(data, keyPair.getPublicKey());
System.out.println("Encrypted Data: " + encryptedData);
String decryptedData = decrypt(encryptedData, keyPair.getPrivateKey());
System.out.println("Decrypted Data: " + decryptedData);
} catch (Exception e) {
e.printStackTrace();
}
}
}
四、结合使用AES和RSA
为了同时利用对称加密的高效性和非对称加密的安全性，通常会将两者结合使用，即使用RSA加密AES密钥，使用AES加密实际数据。以下是结合使用AES和RSA的示例代码：
package cn.juwatech.encryption;
import javax.crypto.Cipher;
import javax.crypto.KeyGenerator;
import javax.crypto.SecretKey;
import javax.crypto.spec.SecretKeySpec;
import java.security.*;
import java.util.Base64;
public class HybridEncryption {
private static final String AES_ALGORITHM = "AES";
private static final String RSA_ALGORITHM = "RSA";
// 生成AES密钥
public static SecretKey generateAesKey() throws Exception {
KeyGenerator keyGen = KeyGenerator.getInstance(AES_ALGORITHM);
keyGen.init(256);
return keyGen.generateKey();
}
// 生成RSA密钥对
public static KeyPair generateRsaKeyPair() throws Exception {
KeyPairGenerator keyGen = KeyPairGenerator.getInstance(RSA_ALGORITHM);
keyGen.initialize(2048);
return keyGen.generateKeyPair();
}
// 使用AES加密数据
public static String encryptData(String data, SecretKey aesKey) throws Exception {
Cipher cipher = Cipher.getInstance(AES_ALGORITHM);
cipher.init(Cipher.ENCRYPT_MODE, aesKey);
byte[] encryptedData = cipher.doFinal(data.getBytes());
return Base64.getEncoder().encodeToString(encryptedData);
}
// 使用RSA加密AES密钥
public static String encryptAesKey(SecretKey aesKey, PublicKey publicKey) throws Exception {
Cipher cipher = Cipher.getInstance(RSA_ALGORITHM);
cipher.init(Cipher.ENCRYPT_MODE, publicKey);
byte[] encryptedKey = cipher.doFinal(aesKey.getEncoded());
return Base64.getEncoder().encodeToString(encryptedKey);
}
// 使用RSA解密AES密钥
public static SecretKey decryptAesKey(String encryptedAesKey, PrivateKey privateKey) throws Exception {
Cipher cipher = Cipher.getInstance(RSA_ALGORITHM);
cipher.init(Cipher.DECRYPT_MODE, privateKey);
byte[] decodedKey = Base64.getDecoder().decode(encryptedAesKey);
byte[] decryptedKey = cipher.doFinal(decodedKey);
return new SecretKeySpec(decryptedKey, AES_ALGORITHM);
}
// 使用AES解密数据
public static String decryptData(String encryptedData, SecretKey aesKey) throws Exception {
Cipher cipher = Cipher.getInstance(AES_ALGORITHM);
cipher.init(Cipher.DECRYPT_MODE, aesKey);
byte[] decodedData = Base64.getDecoder().decode(encryptedData);
byte[] decryptedData = cipher.doFinal(decodedData);
return new String(decryptedData);
}
public static void main(String[] args) {
try {
String data = "Hello, World!";
KeyPair rsaKeyPair = generateRsaKeyPair();
SecretKey aesKey = generateAesKey();
String encryptedData = encryptData(data, aesKey);
String encryptedAesKey = encryptAesKey(aesKey, rsaKeyPair.getPublicKey());
System.out.println("Encrypted Data: " + encryptedData);
System.out.println("Encrypted AES Key: " + encryptedAesKey);
SecretKey decryptedAesKey = decryptAesKey(encryptedAesKey, rsaKeyPair.getPrivateKey());
String decryptedData = decryptData(encryptedData, decryptedAesKey);
System.out.println("Decrypted Data: " + decryptedData);
} catch (Exception e) {
e.printStackTrace();
}
}
}
五、总结
本文详细介绍了在Java中实现数据加密与解密的几种常见技术，包括对称加密算法（AES）、非对称加密算法（RSA）以及结合使用AES和RSA的混合加密技术。这些技术可以有效地保护数据的安全性，防止未经授权的访问。
本文著作权归聚娃科技微赚淘客系统开发者团队，转载请注明出处！