Cryptography is specific term- but if we can generalise it to mean transferring messages that other people(or animals) cannot see, then I have just the animal for you. Behold, the peacock mantis shrimp.

This answer gives me tremendous pressure. Many Chinese began to dox me. They published a lot of my private information. They also reported this answer to the police. I received indirect warnings from police.

Did you update your Windows to 10? Whether your answer is yes or no, you must be familiar with this picture. At first glance, you guys would consider it as a nice work of photoshop, but in fact, it's just