Google has increased the amount it will pay security researchers for information about flaws in its Chrome browser, having already shelled out more than $2m in bug bounties across its various security reward programs.

"In a nutshell, bugs previously rewarded at the $1,000 level will now be considered for reward at up to $5,000," Chris Evans and Adam Mein, the Chocolate Factory's "masters of coin", wrote in a blog post on Monday.

The higher rewards will be offered to researchers who discover bugs that pose "a more significant threat to user safety," and who provide an accurate analysis of the threats and how easy they would be for attackers to exploit.

Even with the increased reward amounts, Google will continue to offer additional bonuses for certain types of bug disclosures, such as when a researcher finds a bug in an area of the code that was thought to be stable, or when a bug also has consequences for other software besides Chrome.

The online ad-slinger says it has already paid out more than $1m in bounties through its Chromium Vulnerability Reward Program and its Pwnium competition, plus another $1m or so for its Google Web Vulnerability Reward Program.

The bounties have been good business for some hackers, several of whom have claimed multiple awards. One of the most frequently rewarded Chrome bug hunters, Sergey Glazunov, has claimed bounties totaling more than $150,000 to date.

But then, that's still peanuts compared to what Google would have to pay Glazunov and his fellow bug-bounty winners to work as security staffers on the Chrome team. In fact, a recent paper published by researchers at the University of California at Berkeley found that over a three-year period, Google's bug bounty programs cost it less than it would likely have paid a single full-time employee.

In effect, Monday's rate increase means Google's crowdsourced, virtual security researcher just got a raise – albeit not a very big one.

Hackers who are interested in cutting themselves a slice of Google's bug-bounty pie are directed to the company's guidelines for reward eligibility, as well as to its directions explaining how to do a good job of reporting bugs. ®