Error encode/decode Base64 between Java and Android

Question

I have a problem when I encode/decode Base64 between Java and Android.

Here is my case:

I write code to encrypt/decrypt using ECC on Java, my code work very well

Answer 1

This seems to be a simple mistake. You replaced

String abc = Base64.getDecoder().decode(encrypt);

with

byte[] encodeBytes = null;
encodeBytes = Base64.encode(my_encrypted_string.getBytes(),Base64.DEFAULT);

if I read this correctly. Try to replace that with decode instead.

As the ciphertext is Base64 encoded twice instead of decoded before attempting to decrypt it, decryption fails with the error you showed us.