[junto]

I'm using TextSecure on my Android phone as a Messaging replacement and it is great. However it appears to me that the service is not decentralised in any way. Is that assumption correct?

I like the email model such that anyone can install and run an email server. I'd actively push friends, family and colleagues to use a decentralised email replacement that was as easy to use and secure as TextSecure.

[drdaeman]

From what I understand, there's some federation baked into the protocol and it works with Cyanogenmod (they run a server for their users), but it's not really documented anywhere in detail.

[XorNot]

I don't trust TextSecure. It's too transparent. It is entirely unclear what happens if it can't send an encrypted message. It's unclear where and how much I'll be billed (important to those of us outside the US). And sans user authentication, there's no real trust model there.

[irv]

Feel free to not trust it, but it does indicate whether the message to be send will be encrypted or not: in the current version, a padlock will be locked or unlocked on the send button. If you receive an unencrypted message from another text secure user, it automatically detects the other party is using text secure and offers to initiate key exchange.

The billing criticism is fair and warranted; currently if your sending over SMS, the first message can only contain 60 chars due to protocol overhead, so you often end up with short messages costing multiple SMS.

There is a way to verify keys (manually!) but no indication that you have verified them.