Google has been using a service codenamed Bouncer to scan of applications submitted to the Android Market in an effort to improve security, the company revealed last week.

Bouncer scans the market for potentially malicious software without disrupting the user experience or requiring developers to submit to an application approval process, said Hiroshi Lockheimer, vice of engineering for Android.

Google also analyses new developer accounts to help prevent malicious developers from coming back, Lockheimer said. Bouncer has been in use for a while; Google found that between the first and second halves of last year, there was a 40 percent decrease in the number of potentially malicious downloads from Android Market.

"While it's not possible to prevent bad people from building malware, the most important measurement is whether those bad applications are being installed from Android Market - and we know the rate is declining significantly," Lockheimer said. Android, he said, already offers security features like sandboxing, which puts virtual walls between applications and other software on a device, and permissions for managing preferences.