Not a single person claimed Google's Project Zero prizes, even after six months of being open to participants.

The Project Zero campaign aimed to attract participants who could find a remote vulnerability or bug chain on Android devices - but they could only use the device's phone number and email address.

The company aimed to gain insights about how remote Android exploits work - and admitted that it's rare to see one in action.

A US$200,000 reward was offered for first price, second prize was worth US$100,000 and at least $50,000 to third prize entries.

In a blog post last month, Project Zero's Natalie Silvanovich says that there were a number of factors that caused the project to fail.

She says that there were no valid entries or bugs - instead there was just spam and entries that did not resemble what the company was after.

After speaking to teams who had planned to submit entries but did not do so, the Project Zero organisers found that there were significant problems with their campaign.

Silvanovich explains that fully remote Android bugs aren't often reported.  While most bugs require victim input such as clicking a link, it was forbidden as part of the contest.

She also suggests that bugs of this nature take time - perhaps the timeframe and reward amount wasn't enough to attract interest.

The prize amounts could have also been too low in regards to the type of bugs Project Zero was looking for.

She also cites other competitions of a similar nature and participants chose to save their bugs for those contests.

While the project did encourage people to come forth with partial bug chains, even if they didn't have the full one. Users were allowed to use bugs they'd filed at any point. If they weren't used as part of the chain, they would have received Android Security Rewards.

“We expected these rules to encourage participants to file any bugs they found immediately, as only the first finder could use a specific bug, and multiple reports of the same Android bug are fairly common. Instead, some participants chose to save their bugs for other contests that had lower prize amounts but allowed user interaction, and accept the risk that someone else might report them in the meantime,” Silvanovich says in the blog.

Project Zero is also looking for feedback from users about how the rules or contest affected their participation.