Speaker 1: Would you be comfortable living in a house that someone else had the key to? What if an underground tunnel led into it from a public park, where its windows could never quite close all the way? Would you trust it with your safety and your privacy? The internet is that house. This is not to say never go into the house, but rather, you should know the hazards before you store all of your valuables there, and do what you can to protect them. So why is it insecure, and why can't we just fortify it until it's safe? Well first of all, the internet was not originally built to be what it is today. It's like someone decided to expand a shoebox into a skyscraper. The internet originally developed when computers were huge and so expensive to own that only universities, big businesses, and a few governments had them. The point, originally, was to let these massive supercomputers talk to each other. And as soon as two computers could send information back and forth, we had a network. The network gradually grew until personal computers emerged in the 1980s. And then, it exploded. Soon people were not just talking to each other, but also exchanging money, playing games, reading news, shopping, and doing everything we associate with the internet today. Other devices started talking to the network, too. Phones, and cars, and refrigerators, and elevators, and power plants, and much, much more. But the ease of all those devices talking to each other came at a price. Security. One computer could send another instructions to delete everything on it, or take it over. We call these viruses and malware. Or one person could steal another's identity by guessing, cracking, or extracting a password. Vulnerabilities such as these will never completely go away, because they're built into the internet's very architecture. Criminals use them to steal billions of dollars, governments use them for surveillance, and hacktivists use them to further their political goals. Between 2004 and 2013, over one billion records of personal information were stolen or leaked through data breaches of major organizations. As a thought experiment, let's imagine what a perfectly secure internet might look like. Users would not be allowed to download or install anything onto their computers. All internet traffic would be monitored and regulated by bots and humans, massively limiting the number of websites you could visit. In order to log on to a website, you'd have to type in a 100-character password, submit a genetic sample, and whistle a tune. The servers that hold data would be kept in heavily armed fortresses on the moon. And even with all these safeguards in place, some clever hacker would almost certainly still find a way in. The good news is, even with our flawed internet, there are simple things you can do to protect yourself, and there are a lot of people committed to making the internet more secure. In Nova's Cyber Security Lab, you'll play as one of these people, protecting a company that's the target of increasingly sophisticated cyberattacks. You must continuously strengthen your defenses to thwart these attackers. You'll do this by completing challenges that will give you basic coding abilities, help you spot scams designed to trick you into giving up your secrets, and teach you how passwords are cracked and strengthened. The house that is the internet may be built on a shaky foundation, but it's been a home to innovation and an unprecedented free exchange of ideas. It's up to us to make it livable in spite of its flaws.