As the internet continues to limp toward better security, sites have increasingly embraced HTTPS encryption. You’ve seen it around, including here on WIRED; it’s that little green padlock in the upper lefthand corner, and it keeps outside eyes from snooping on the details of your time online. Today, the biggest porn site on the planet announced that it’s joining those secured ranks. Pornhub’s locking it down, and that’s a bigger deal than you’d think.

Today, Pornhub turned on HTTPS by default across the entirety of the site. On April 4 its sister site, YouPorn, will do the same. By doing so, they’ll make not just adult online entertainment more secure, but a sizable chunk of the internet itself.

The Pornhub announcement comes at an auspicious time. Congress this week affirmed the power of cable providers to sell user data, while as of a few weeks ago more than half the web had officially embraced HTTPS. Encryption doesn’t solve your ISP woes altogether—they’ll still know that you were on Pornhub—but it does make it much harder to know what exactly you’re looking at while you're there.

“If you’re visiting sites that allow HTTPS, you don’t have to worry so much about what they’re doing to observe your traffic,” says Joseph Hall, chief technologist at the Center for Democracy and Technology, a digital rights group that has offered HTTPS assistance to the adult industry, but was not part of Pornhub or YouPorn’s switch. That’s especially important for porn sites, and not just for prudes. In countries and cultures where homosexuality is considered a crime, for instance, encryption can be critical.

To get a sense of just how big this Pornhub news is, though, it helps to get a sense of Pornhub’s size.

Traffic Hub

It can be hard to keep porn sites straight, since so many of them sound like parodies to begin with, and mostly seem to follow the same basic rubric. Pornhub stands out, though, as not just the biggest adult site in the world, but one of the biggest sites over all.

Just how much traffic flows through Pornhub on any given day? Try 75 million daily visitors. According to Alexa site rankings, that makes it the 38th largest website overall, sliding in one slot below Ebay. It’s bigger than Wordpress. It’s bigger than Tumblr. It’s only a few spots down from Netflix. It’s a behemoth.

YouPorn’s no slouch either; it cracks the Alexa top 300, and serves a billion (with a b) video views every month.

In fact, that both Pornhub and YouPorn are predominantly video-based makes their HTTPS transition all the more consequential—and difficult. There are plenty of challenges to HTTPS implementation, but among the biggest is that it requires any content coming in from the outside—like third-party ads—to be HTTPS compliant. For a video-heavy site, there’s the added challenge of finding a content delivery network—the companies that own the servers that shuttle web pages and videos across the great wide internet——that’s willing to take on that volume of encrypted video.

“Finding CDN providers to handle the massive amount of traffic, but also stream through HTTPS is never easy,” says Pornhub vice-president Corey Price. “There are few providers worldwide that can handle our levels of traffic, especially in HTTPS.” Price declined to give specific names, but says that Pornhub has managed to enlist three “large CDN partners” to handle the switchover.

HTTPS comes with other inherent challenges as well, especially on a site of this size. Fortunately, Pornhub wasn’t starting from scratch. Its parent company, MindGeek, also owns a popular adult site called RedTube, which made the transition earlier this month. And Pornhub itself had already dabbled as well, offering HTTPS for its paid Pornhub Premium service late last year.

“The biggest learning was finding ways to mitigate the site speed impacts of switching to HTTPS, as many of the techniques we used don’t have the same effect with HTTPS,” says Price.

Encrypt It All

On its own, Pornhub’s HTTPS embrace will secure a significant portion of the web literally overnight. It also has broader importance, though.

First, it’s part of MindGeek’s commitment to rolling out HTTPS across all of its properties. That’s over 100 million unique visitors every single day that will eventually enjoy a secure connection. Facebook nets 200 million in a month. The only question is when, not if, that’s going to happen.

“All properties are managed independently with different engineering teams,” says Price. “Each team always faces different challenges as each site is an entirely different codebase. Some features and changes can take a couple of hours to do on Pornhub, but take weeks on YouPorn, and vice-versa.”

More significantly, it signals that encryption has become the norm on the web. Broad HTTPS adoption is great, but nothing beats concentrated implementation among the very biggest sites.

“The reason that a lot of us are focused on the top 100 websites is because so much of web traffic is represented by those sites,” says Hall. “Right now we’re at 50 percent of all web browser connections on HTTPS. If we were to get the top 100, that would easily get to 80 or 90 percent.”

That's still a ways off. But on April 4, two sites will keep the internet that much safer from all kinds of prying eyes.