Yeah it would be cool to give solutions once the task is finished. Explain the different aspects that could have been used during the task for anyone that may have missed something.

It would also be a good way to learn, the whole point is to allow people who may not know much about it to join in with a bit of reading.

Some websites such as http://www.enigmagroup.org/ do it very well already and have a good ethos around learning and developing knowledge and skills in the area.