The TSA isn't about making air travel safe but to make people 'feel' safe.
After 9/11 the public felt unsafe and stopped flying. Now that the TSA and their moronic security theater is in place, the travellers are back, and so the TSA's goal is achieved.
Neither confiscating fluids, invading old ladies' underwear nor encrypting electronic signals enhance safety. But inconviniencing travellers gets noticed as it happens in public and the media writes about it. The encryption will go unnoticed.