I love AgileBits (makers of 1Password). It's pretty clear that the highest risk is pure-cloud services. There, it's trivial to get a legal order or technical

I love AgileBits (makers of 1Password). It's pretty clear that the highest risk is pure-cloud services. There, it's trivial to get a legal order or technical compromise to steal the data. A "hostproof", download-on-each-use app, like LastPass, is essentially the same risk as a cloud app. (this is the hushmail and lavabit vulnerability.) The safest is some kind of purely-client software, with local data, which operates online, and is never updated. Ideally open source, with a trustworthy build process. In between is software like 1Password. I wouldn't consider 1Password + Dropbox sync to be safe -- NSA has open-door access to Dropbox if they wish to get a single user's data (and possibly more). Tricking a user into download a compromised version of 1Password wouldn't be terribly difficult even without the cooperation of AgileBits. You can use 1Password more safely (local-only, infrequently updating, some kind of local-firewalling in the client, etc.). Without the client being open source, it's really difficult to do more. It's probably a hell of a lot safer on OSX than it is on iOS, since at least some OSX users are likely to do real network monitoring, or otherwise be on some kind of debugging enabled system, or something with just weird bugs, uncover a problem, and then dig into it and find a backdoor -- on mobile, there's little risk of that.