The deluge of cyberattacks sweeping across the world has governments and companies thinking about new ways to protect their digital systems, and the corporate and state secrets stored within. For a long time, cybersecurity experts have erected firewalls to keep out unwanted traffic and set up decoy targets on their networks to distract hackers who do get in. They have also scoured the internet for hints about what cybercriminals might be up to next to better protect themselves and their clients.