"Ephemeral" messages, the way Snapchat does it, is useless against surveillance and possibly even other kind of hacking later on if the company is actually savi

"Ephemeral" messages, the way Snapchat does it, is useless against surveillance and possibly even other kind of hacking later on if the company is actually saving the content on its servers. Perfect forward secrecy is a much better way to have "ephemeral" conversations, even if the encrypted data remains stored. Adding self-deletion on top of that just makes it slightly better in case someone wants to decrypt those messages later, even though it should be an almost impossible task. So if apps want to offer safe conversations for users, they should first implement end to end security and perfect forward secrecy either with OTR or TextSecure's protocol. If they want to add self-deletion on top of that mainly as a marketing feature, that's fine, but it shouldn't be the main priority.