>> guarantee the recipient list won't be leaked. Basically , if you A. Put a chain of servers between the sender and the recipient, each with a unique encrypt

>> guarantee the recipient list won't be leaked. Basically , if you A. Put a chain of servers between the sender and the recipient, each with a unique encryption key(which lets you reveal unique info for each server privately) B. Make sure to hide traffic patterns: don't let your enemy know when sender is sending a message or when recipient is receiving a message. This can be done by creating false traffic at fixed times to hide true traffic. you can design protocols that make sure that: 1. The first server in the chain only knows the sender. 2. The last server on the chain only the recipient. 3. Assuming you enemy hasn't cracked all the chain, he can't link sender and recipient I don't know alot about the XMPP protocol(whichthey are using) , so i'm not sure how it fits all this though.