This sounds like a relatively simple substitution cypher. They are pretty easy to break. Of course, the person who claims to have a cypher must show that it really is a code, and not just random noise. They have to show that a message can be sent and decoded from their code.
Anyone can send a set of garbage, demand that someone “break the code”, and claim that it is unbreakable when there is no message.
The second image at the link is an example message using this cypher. It appears his cypher maintains formatting of the original message which should make cracking it all the easier. With the common pairs in the example document, it appears to be a combination of substitution and cypher key, which again is a huge hole for someone to decode the message from. Least I get the very strong impression that the FQ pair is a substitution for the space.
Cryptography is a skill of patience I don't have, but if this is the challenge, I think it's going to be pretty dang easy to break.