如何使你的电子邮件真正安全

In my Scientific American column this month, I opined that email never really has been a secure communications channel -- and that, in the age of suspected Russian hacking, Wikileaks, and countless other high-profile hacks, it never will be.

But suppose you want to communicate securely. What are your options?

Here's a quick look at some of the ways you can carry on encrypted conversations, without worrying that your words could be captured and used against you someday. As you'll soon see, there's no one-click solution that can encrypt all of your correspondence all the way to your colleagues.

Gmail. Your outgoing Gmail messages are encrypted -- but they don't stay encrypted unless the recipient is reading email using a Google browser or Gmail app. And, of course, Google itself freely admits that its software reads all of your email for advertising purposes (not its human employees, which you may or may not believe).

Outlook. Some programs, like the paid version of Outlook, offer an encryption feature. But setting it up is messy, and definitely not for the masses. It requires that you and your recipient exchange something called a digital signature, and following these 8 simple steps.

Secure email services. Email providers like Tutanota, Ghostmail, and Protonmail automatically encrypt all the mail you send. The catch -- and you knew there would be one -- is that your recipient must also subscribe to that service, or enter a password to open each message you send. (There are free accounts, but they limit the size of your messages and attachments.) They're fine if your only secure conversations are with one or two people, but you're never going to persuade the whole world to sign up so that they can get your emails.

Chat programs. Another option for those wishing to send secure text correspondence: Don't use email at all. Instead, use a chat program like CryptoCat, ChatSecure, or PQChat. These apps encrypt your messages on both ends and throughout their transmission. Here again, though, they limit your communication to people who also have and use those same apps.