Pwnium began as Google’s answer to Pwn2Own, the well-known hacking contest that has attracted some of the top researchers in the industry over the course of the last few years, including Dino Dai Zovi, Charlie Miller, Chaouki Bekrar and the Vupen team and many others. Pwn2Own has traditionally not required contestants to submit complete exploit information, but rather the details of the vulnerability and the crash data. Pwnium requires researchers to submit full exploits, something that has kept some of the potential contestants away, notably the Vupen team.
But the money that Google is putting up for new compromises of Chrome OS is far beyond what’s available at Pwn2Own or any of the other major contests and has attracted a small, but elite, group of contestants in past years. The company is promising rewards of as much as $150,000 plus some bonuses, paid at Google’s discretion, for especially innovative or serious exploits."