In a shift from its usual strategy of casting aside the hacker community, Apple recently solicited security experts, and asked them to find discrepancies in the new upcoming Mac OS X Lion.

Apple e-mailed several well known researchers such as Charlie Miller and Dino Dai Zovi, who co-authored the Mac Hacker’s Handbook, and offered them a free copy of the OS X Lion in exchange for information. The deal also encompasses a non-disclosure agreement that would prevent the researchers from publicly stating their findings.

The Mac Observer published a copy of the email sent by Apple, “I wanted to let you know that I’ve requested that you be invited to the prerelease seed of Mac OS X Lion, and you should receive an invitation soon. As you have reported Mac OS X security issues in the past, I thought that you might be interested in taking a look at this. It contains several improvements in the area of security countermeasures.”

Dai Zovi tweeted confirming the invite, saying, “Apple has invited me to look at the Lion developer preview…I won’t be able to comment on it until its release, but hooray for free access!” In an interview, Miller remained skeptical of Apple, saying to ComputerWorld, “they’ve never done this before…That they’re thinking of reaching out [to researchers] is a good positive step, but whether it makes a difference, I’ll believe it when I see it.”

Miller has been a vocal critic of Apple’s security measures, stating back in 2008 that the Mac OS X was more vulnerable than Linux and Windows. Miller has proven this by winning numerous Pwn2Own hacking contests for finding and exploiting vulnerabilities in Mac OS X, Safari and Apple Browser. He will also participate at this year’s Pwn2Own, reports ComputerWorld.

According to Cnet, the new OS X Lion is set to have several new features such as Mission Control and Launchpad, and that according to Apple, the OS X, “takes some of the best ideas from iPad and brings them back to the Mac.”