Serzh's questions

我发现一个观点认为最好对整个数据库进行加密，并且在加密期间可以看到一些元数据。我们在谈论什么元数据，我应该怎么做（我已经创建了一个加密每个条目的程序）

AES CBC 会截断长度超过 16 个字符的字符串。下次运行时，它显示 javax.crypto.BadPaddingException: Given final block not properly padded. Such issues can arise if a bad key is used during decryption.

UPD：这是有问题的代码：

public static byte[][] encrypt(String txt, String txt2, String txt3){
try {
            SecretKey mysecretKey = new SecretKeySpec("qwertyuiopasdfgh".getBytes(), "AES");
            byte[] plainText1 = txt.getBytes();
            byte[] plainText2 = txt2.getBytes();
            byte[] plainText3 = txt3.getBytes();
            byte[][] plain_bytes = new byte[][] { plainText1, plainText2, plainText3 };
            IvParameterSpec iv = new IvParameterSpec("4283810222669651".getBytes());
            cipher = Cipher.getInstance("AES/CBC/PKCS5Padding");
            cipher.init(Cipher.ENCRYPT_MODE, mysecretKey, iv);
            cipher.update(plainText1);
            byte[] cipherText1 = cipher.doFinal();
            cipher.update(plainText2);
            byte[] cipherText2 = cipher.doFinal();
            cipher.update(plainText3);
            byte[] cipherText3 = cipher.doFinal();
            byte[][] encrypted_bytes = new byte[][] { cipherText1, cipherText2, cipherText3 };
            String str = Base64.getEncoder().encodeToString(encrypted_bytes[0]);
            encryptedUrl = str;
            System.out.println(encryptedUrl);
            return encrypted_bytes;
        } catch (Exception e1) {
            e1.printStackTrace();
            return null;
    
}
    }