I personally think finding solutions of homework questions on StackExchange is one of the wonderful things that couldcould've happen.
Because:
1- Firstly, questions are usually answered with enough delay that the person asked, definitely won't be able to write the solution for their homework.
2- Teachers are forced to change their questions or modify them a bit, so the number of new educational question in the cryptography field increases.
3- Some of the questions are explained such elaborately, while we can be sure for years there will be no textbooks that cover them!
4- All people don't have access to experts or experienced teachers, so their teachers don't know the answers, too. At these moments, hints are not helpful. The solutions are the cure.
5- Learning in traditional way is not effective. We need a machine-learning approach, i.e., tons of examples and then tests. A huge dataset, then bringing up test set. There are not much question-answer's in the cryptography field.
Now It's the time to ask, with this mindset, "Do we support homework questions more strongly?"