Does encryption negate the intelligence-collecting capabilities that Edward Snowden revealed such as PRISM, which allows the NSA to search anyone's email by just looking up their name?
Peter Eckersley, chief computer scientist, Electronic Frontier Foundation: Unfortunately we aren't close to having any sort of encryption that would protect the contents of your email against a PRISM-like attack. We need to build these things, but the strong encryption that is being debated right now doesn't do that. We are maybe getting there with text messages, but don't have a way to do end-to-end email encryption yet. Not a practical one.
Services like Silent Circle or Whisper offer end-to-end encryption, but are not yet a practical replacement for email. There's a technology called PGP which has been around for a while, but it's not yet practical for email for most people.
There are some big technical differences between email and text messaging which make email a lot harder: People expect to have all their old emails; they expect to be able to search all their old emails really fast from a phone even if they have 10GB worth of messages which they couldn't store locally on their device. Today's email platforms have very sophisticated spam filtering and prioritization features that have been built into these email platforms. To replicate all that functionality in an end-to-end encrypted system is an unsolved problem.