TOKYO—Waiting for his mother to finish grocery shopping one day in 1994, 12-year-old Daisuke Okanohara passed the time with a little reading—of a research paper describing a new method to speed up data compression. He says he felt his body shake with excitement.

“It was a breathtaking method,” recalls Mr. Okanohara, now 33. He spent months testing it to see how it worked.

Today,...