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An example of using RSA to encrypt a single asymmetric key

import java.security.Key; import java.security.KeyPair; import java.security.KeyPairGenerator; import javax.crypto.Cipher; import javax.crypto.KeyGenerator; import javax.crypto.SecretKey; import javax.crypto.spec.SecretKeySpec; public class MainClass {   public static void main(String[] args) throws Exception {     KeyGenerator keyGenerator = KeyGenerator.getInstance("Blowfish");     keyGenerator.init(128);     Key blowfishKey = keyGenerator.generateKey();     KeyPairGenerator keyPairGenerator = KeyPairGenerator.getInstance("RSA");     keyPairGenerator.initialize(1024);     KeyPair keyPair = keyPairGenerator.genKeyPair();     Cipher cipher = Cipher.getInstance("RSA/ECB/PKCS1Padding");     cipher.init(Cipher.ENCRYPT_MODE, keyPair.getPublic());     byte[] blowfishKeyBytes = blowfishKey.getEncoded();     System.out.println(new String(blowfishKeyBytes));     byte[] cipherText = cipher.doFinal(blowfishKeyBytes);     System.out.println(new String(cipherText));     cipher.init(Cipher.DECRYPT_MODE, keyPair.getPrivate());     byte[] decryptedKeyBytes = cipher.doFinal(cipherText);     System.out.println(new String(decryptedKeyBytes));     SecretKey newBlowfishKey = new SecretKeySpec(decryptedKeyBytes, "Blowfish");   } }