Google yesterday said it would shut down its Pwnium hacking contest, which it has held alongside the better-known Pwn2Own challenge each spring since 2012.
Instead, Google will focus on its long-standing bug bounty program.
"Pwnium will change its scope significantly, from a single-day competition held once a year at a security conference to a year round, worldwide opportunity for security researchers," wrote Chrome security engineer Tim Willis in a Tuesday blog post.
Last year, Google paid out $190,000 from its Pwnium pool to two researchers who demonstrated multi-vulnerability chains that exploited Chrome OS, the search giant's browser-based operating system. George Hotz, a noted iPhone and Sony PlayStation hacker, was handed $150,000 by Google for what the firm called "an epic Pwnium competition win," while another researcher, known only as "Pinkie Pie," was awarded $40,000 for a partial exploit.
Pwnium had attracted attention for its large awards -- up to $150,000 for each hack -- the $3.14 million Google had pledged in 2013 to spend if necessary, and the focus on Chrome OS.
Willis took a shot or two at Pwn2Own, the hacking contest run by HP TippingPoint's Zero Day Initiative (ZDI), a rival bug bounty program, as he explained Google's reasons for folding up the Pwnium tent.
"At Pwnium competitions, a security researcher would need to have a bug chain in March, pre-register, have a physical presence at the competition location and hopefully get a good time slot," said Willis. "[And] if a security researcher was to discover a Pwnium-quality bug chain today, it's highly likely that they would wait until the contest to report it to get a cash reward. This is a bad scenario for all parties."
ZDI's Pwn2Own requires that researchers -- or a representative -- be physically at the contest, which is held at the CanSecWest security conference in Vancouver, British Columbia. Pwn2Own hands out cash prizes only for until-then-unknown vulnerabilities.
Rather than sponsor Pwnium, Google will boost the maximum award in its own bounty program to $50,000 for "Pwnium-style bug chains on Chrome OS," Willis added. Those rewards will be available year-round.
At times, there has been tension between Google and ZDI over hacking challenges.
In 2012, Google first said it would partner with ZDI to pitch in prize money for Pwn2Own, then withdrew that offer. Google objected to Pwn2Own rules that did not require contestants to reveal to vendors a complete exploit or all the vulnerabilities used in a demonstration.
ZDI contested Google's assertions, arguing that prize money -- even the then-top $60,000 -- wasn't enough to shake loose the very rare sandbox-escape vulnerabilities and ensuing exploits against the Chrome browser target.
Rather than back out completely, Google launched Pwnium, which also ran during CanSecWest.
Google will remain a sponsor of this year's Pwn2Own; its Project Zero team will not only help pay for the contest's prizes, but separately will award up to $10,000 for entries that successfully exploit the latest release of Chrome 42.
HP TippingPoint declined to comment on Google's decision to scrap Pwnium.
Pwn2Own will take place March 18-19, with $465,000 in awards up for grabs.