RSA非对称加密学习

设计方案：
单位生成密钥对：每个单位（A、B、C、D等）生成自己的 RSA 密钥对，包括一个私钥和一个对应的公钥。

A单位加密数据：单位A作为数据加密方，使用其他单位的公钥对数据进行加密。

其他单位解密数据：其他单位使用自己的私钥对接收到的加密数据进行解密。

Java 代码示例：
以下是一个简化的 Java 代码示例，使用 RSA 算法进行数据的加密和解密。

import javax.crypto.Cipher;
import java.security.*;
import java.util.Base64;public class RSAEncryptionExample {public static void main(String[] args) throws Exception {// Unit A - Data Encryption UnitKeyPair unitAKeyPair = generateKeyPair();PublicKey unitAPublicKey = unitAKeyPair.getPublic();PrivateKey unitAPrivateKey = unitAKeyPair.getPrivate();// Other units (B, C, D)PublicKey sharedPublicKey = unitAPublicKey; // Assume other units have access to A's public key// Simulate data encryption by Unit AString dataToEncrypt = "Sensitive data";String encryptedDataByA = encryptData(dataToEncrypt, sharedPublicKey);// Simulate data decryption by other units (B, C, D)String decryptedDataByB = decryptData(encryptedDataByA, unitAPrivateKey);// Display resultsSystem.out.println("Encrypted data by A: " + encryptedDataByA);System.out.println("Decrypted data by B: " + decryptedDataByB);}private static KeyPair generateKeyPair() throws Exception {KeyPairGenerator keyPairGenerator = KeyPairGenerator.getInstance("RSA");keyPairGenerator.initialize(2048); // Change this size based on your security requirementsreturn keyPairGenerator.generateKeyPair();}private static String encryptData(String data, PublicKey publicKey) throws Exception {// Encryption using RSA algorithm with a public key// Initialize RSA Cipher in encryption modeCipher cipher = Cipher.getInstance("RSA");cipher.init(Cipher.ENCRYPT_MODE, publicKey);// Encrypt the databyte[] encryptedBytes = cipher.doFinal(data.getBytes());return Base64.getEncoder().encodeToString(encryptedBytes);}private static String decryptData(String encryptedData, PrivateKey privateKey) throws Exception {// Decryption using RSA algorithm with a private key// Initialize RSA Cipher in decryption modeCipher cipher = Cipher.getInstance("RSA");cipher.init(Cipher.DECRYPT_MODE, privateKey);// Decrypt the databyte[] decryptedBytes = cipher.doFinal(Base64.getDecoder().decode(encryptedData));return new String(decryptedBytes);}
}