As Japan gears up for the 2020 Olympics in just over a year, it needs to brace for sophisticated cyberattacks, experts say.

With the proliferation of smart devices and drones, such attacks are likely to increase not only in number, but also in complexity.

Previous Olympic organizers have faced an enormous number of cyberattacks, with 500 million estimated during the 2016 Rio Games and 250 million during the 2012 London Games. The threat to Tokyo is expected to be on a similar scale.