The radio waves emitted by humanity this time did not employ a variety of complex encryption methods. To try and hide their signal behind heavy encryption in such a situation would only make them look petty and suspicious; Jason and his team certainly weren't going to make such a rookie mistake.
Instead, the humans used a very conventional method of information encoding that wasn't difficult to decrypt, but they chose to transmit it in a relatively difficult language: English!
They chose this language not because it was the dominant language aboard the Noah, but simply because of its sheer difficulty. English is notoriously complex, filled with numerous contradictions, idioms, and irregular grammar rules. They aimed to use this to delay the aliens' decoding speed as much as possible, thereby highlighting humanity's own "advantage" of lightning-fast decryption!
