Encrypt/Decrypt output & input for SSIS task
Encrypting files through SSIS is possible, but there is no real easy native solution available with SSIS. There are a wealth of third party productions out there than can assist with this. Time is money, so it all depends on how much you want to spend on trying to come up with a customized solution or just go buy something that can help you do it quicker.

There is a good write up on this blog post that walks thorugh doing it with some custom .NET code and a ScriptTask. He also list out some of the third party products that offer a solution as well.