Recently a question on Project Euler site made me think about easily verifiable but hard to generate messages. This can have some cryptographic use. The message contains both the content and the verification in one block. Here is an example:
In the above sentence the content is “My name is Otuk” and the rest of the message is for easy verification by the recipient. As long as preparing the verification information is computationally intense, the message cannot be quickly modified. Here we are counting only 8 attributes of the message, to make it more challenging we can simply add more attributes to count and place them as part of the easy verification data. On the other hand verification is always super fast no matter how many attributes are added.
Regardless of the future opportunity for cryptographic usage, there is something interesting about these type of sentences. Trying to write them takes a person to a path where a solution cannot be approached with simple numerical methods, not only it is dynamic & multi-variable but also the results jump wildly until you find a perfect fit. Right before or right after the fit you may be far off from the solution, in other words having a lower error measure does not mean you are getting closer to a solution. There are also no guarantees for a solution at all.