C117 Cryptology
Since he was planning to help Huang Ran save his wife, he naturally needed to have some understanding of this matter and know the cause and effect, or else he would not be able to start from scratch. Moreover, he had just met Huang Ran, so it was impossible for him to trust him 100% of the time.
He even dared to enter the iron prison. In order to save his wife, he was already going all out