Google has increased its bug bounty offers to cybersecurity researchers, offering up to $1.5 million to anyone who can show off a unique attack on its Pixel 3 and 4 phones, as long as they allow for persistent access to the device.

The security researchers will have to break Google's Titan M "secure element." Similar to Apple's iPhone Secure Element, Titan M is a security chip that acts as a kind of guardian for device data.

Google is also offering up to $1.5 million for exploits found on developer preview versions of Android. Rewards for successful hacks of those versions will be given a 50% bonus. Again, Apple announced something similar back in August.

Rewards of up to $500,000 are also on offer for specific attacks that result in data theft and lockscreen bypass. Again, this will be limited to Pixel phones running the latest version of Android.

Google said it's handed out $1.5 million to researchers in the last 12 months. The most it's given to a single researcher was a $161,337 reward from the Android Security Rewards program and $40,000 by the separate Chrome Rewards initiative for a total of $201,337.

Huawei has also its own bug bounty, which had briefly outdone Google in offering $220,000 for a remote control hack of its many Android devices.