Apple's iMessage Encryption Seems to Be Pretty Good
Schneier on Security 2013-04-05
Summary:
The U.S. Drug Enforcement Agency has complained (in a classified report, not publicly) that Apple's iMessage end-to-end encryption scheme can't be broken. On the one hand, I'm not surprised; end-to-end encryption of a messaging system is a fairly easy cryptographic problem, and it should be unbreakable. On the other hand, it's nice to have some confirmation that Apple is looking out for the users' best interests and not the governments'.
Still, it's impossible for us to know if iMessage encryption is actually secure. It's certainly possible that Apple messed up somewhere, and since we have no idea how their encryption actually works, we can't verify its functionality. It would be really nice if Apple would release the specifications of iMessage security.