This is a non-technical description of why Yahoo! Mail is unsafe to use in a public setting, and indeed at all. I will be pointing people at this page as I go through the long process of changing an address I’ve had for more than a decade.
What’s wrong with Yahoo Mail?
A lot of web addresses start with http://–that’s a signal that the “scheme” used to deliver the page to your browser is something called HTTP, which is a technical specification that turns out is a really good way to move around web pages. As the page flows to the browser, it’s susceptible to eavesdropping, particularly over a wi-fi connection, and much more so in public, including the usual hotspots like coffee shops, but also workplaces and many home environments. It’s the virtual equivalent of a postcard. When you’re reading the news or checking traffic, it’s not a big deal if someone can sneak a glance at your page.
Some addresses start with https://–notice the extra ‘s’ which stands for “secure”. This means two things 1) that the web page being sent over is encrypted, and thus unavailable to eavesdroppers, and 2) that the people running the site had to obtain a certificate, which is a form of proof of their identity as an organization (that they’re not, say, Ukrainian phishers). Many years ago, serving pages over https was considered quite expensive in that servers needed much beefier processors to run all that encryption. Today, while it still requires extra computation, it’s not as big of a deal. Most off-the-shelf servers have plenty of extra power. To be fair, for a truly ginormous application with millions of users like Yahoo Mail, it is not a trivial thing to roll out. But it’s critically important.
First, to dispel a point of confusion, these days nearly every site, including Yahoo Mail, uses https for the login screen. This is the most critical time when encryption is needed, because otherwise you’d be sending your password on a postcard for anyone with even modest technical skills to peek at. So that’s good, but it’s no longer enough. Because sites are written so that you don’t have to reenter your password on every single new page, they use a tiny bit of information called a “cookie” in your browser to stay logged in. Cookies themselves are neither good nor bad, but if an eavesdropper gets a hold of one, they can control most of your account–everything that doesn’t require re-entering a password. In Yahoo Mail this includes reading any of your messages, sending mail on your behalf, or even deleting messages. Are you comfortable allowing strangers to do this?
As I mentioned earlier, new, more powerful tools have been out for months that automate the process of taking over accounts this way. Zero technical prowess is needed, only the ability to install a browser plug-in. If there are any web companies dealing in personal information for which this wasn’t a all-hands-on-deck security wake-up, they are grossly negligent. Indeed, other sites like Gmail work with https all-the-time. But still, in 2011, Yahoo Mail doesn’t. I have a soft spot for Yahoo as a former employer, and I want to keep liking them. Too bad they make it so difficult.
The deeper issue at stake is that if this serious of an issue goes unfixed for months, how many lesser issues lurk in the site and have been around for months or years? The issue is trust, my friend, and Yahoo just overdrew their account. I’m leaving.
Q: So what do you want Yahoo to do about this? A: Well, they should fix their site for their millions of remaining users.
Q: What if they fix it tomorrow? Will you delete this message? A: No. Since I no longer trust the site, I am leaving, even though it takes time to notify all the people who still send me mail, and no matter what other developments unfold in the meantime. This page will explain my actions.
Q: Do you really want everyone else to leave Yahoo Mail? A: No, only those who care about their privacy.
Q: What’s your new email address? A: I have a couple, but <my first name> @ <this domain> is a good general-purpose one.
I will continue to update this page as more information becomes available. -m