On Wed, Aug 16, 2017 at 11:47 PM, Deen, Glenn (NBCUniversal) <Glenn.Deen@xxxxxxxxxx> wrote:
The key issue is that no method currently in existence can defeat a camera taking a picture of the screen. That will always let an authorized receiver make a permanent copy of the email and do what they want with it. Yes, you may be throwing away repudiation and signature information, but they will have the contents of the mail.
Absolutely true. And really serious for some applications. But consider the Game of Thrones hack, a screen capture would be serious, yes. But nowhere near as serious as having the final cut leak in HD.
The kids are using snapchat because their principle security concern is that the receiver will forget to delete the pics they send and they will end up with the parents. They understand full well that they can photograph the screen of one phone with another.
The perfect is the enemy of the good.