The encryption that protects your email and social updates is far from flawless -- it's relatively easy for spies to intercept your data using spoofs and hacked servers. If Greg Slepak has his way, though, there will soon be a safer way to send your info. His okTurtles project uses blockchains (the transaction databases you see in virtual currencies like Bitcoin) to let you communicate over the web without the risk of a man-in-the-middle attack. Rather than rely on website security certificates that could easily be compromised, it gives individual users public keys that unlock data within blockchains. There's no centralized authority, and you can even run one of the necessary servers yourself if you don't trust others. When complete, okTurtles will have a browser add-on that lets you use this authentication on virtually any site. You could talk to a fellow okTurtles user through Gmail without worrying that someone besides your recipient could easily read the message, for example.