The maker of the world's most popular mobile operating system says it's now more secure than ever.

Google released its second annual Android Security Report on Tuesday detailing how the company protects over a billion Android devices.



Specifically, last year Google performed over 400 million checks of devices per day for security issues. According to the report, it helped find and wipe over 200,000 lost or stolen devices per day and checked over 6 billion installed applications per day for malware.



"I hate to be negative, but there's a lot of different potential threats that we have to think about and build protections for," Adrian Ludwig, head of Android Security, told CNBC.

Google is investing more every year in Android's security team both in terms of people and computational resources, Ludwig said. Through Google's Vulnerability Rewards Program, for example, Android paid security researchers and hackers more than $200,000 to fix more than 100 vulnerabilities.



The challenge lies in the sophistication of today's security attacks.

"I don't think threats are getting worse," Ludwig said. "I think the attacks are getting more sophisticated, but the defenses are probably moving even faster than the attacks, in the mobile space at any rate. "