I use private key 64 bytes encrypt data 20 bytes.The output (encrypted data) is 64 bytes and I use public key 64 bytes encrypt the data (encrypted data) again the output is 128 bytes long. I want to ask some question if I want the final output just only 64 bytes not 128 bytes.Can I do that? Is the encrypted data will longer everytime I encrypt?

Thank you for your answer.