Paul Sakuma/AP
This is an extension of Google's research grant program, where it pays out funding to independent security experts, in return for lending their time and energy towards making sure Google is as safe as it can be.
The new money is in addition to Google's traditional bounty of up to $20,000, which it pays out to anyone who actually finds a security flaw in the system. The difference is that those security grant recipients aren't actually expected to find vulnerabilities - it's just a way of contracting experts to watch the wall, so to speak.
"The end result of these ongoing efforts is a product that - unlike your garden-variety hard drive - actually gets better over time," writes Google Drive Product Manager Kevin Nelson in that blog entry.
Which is to say, Google is better than you at storing files, and it wants to make sure it stays that way. A million bucks isn't a lot for a company of Google's size, but it shows how seriously it takes the concept of constant improvement.
As an added bonus, the announcement comes alongside a neat video tour of one of Google's massive data centers. Check it out: