“javax.crypto.BadPaddingException: Data must start with zero” exception

Question

I encountered the abovementioned exception while I was decrypting a string.

Below is my code:

import java.security.KeyPair;
import java.security.KeyP         


        

Answer 1

You already asked the same question in "javax.crypto.BadPaddingException: Data must start with zero" exception, and I gave you an answer: you're using two different keypairs : one to encrypt, and another one to decrypt. That can't work. I even gave you a code sample showing that everything ran fine if you used the same keypair.

KeyPairGenerator.generateKeyPair() generates a keypair. Calling this method twice will get you two different keypairs: it uses a random number generator internally to generate always different keypairs.

You must generate a keypair once, store it in a variable, and use this variable to encrypt and decrypt.

You should read the documentation of the classes and methods you are using. The documentation of generateKeyPair says:

This will generate a new key pair every time it is called.