Zdziarski is no stranger to Apple (AAPL), having worked on iOS security matters for years as an independent researcher. He’s written several books on iPhone-related topics, like one book that focused on forensic analysis and recovering data on the smartphones and another book on how to write software for the devices.

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According to his profile on O’Reilly Media Zdziarski’s “research into the iPhone has pioneered many modern forensic methodologies used today, and has been validated by the United States’ National Institute of Justice.”

Zdziarski did not say what his role or starting date with Apple would be, only to say that he will be working with Apple’s security engineering and architecture team. In his blog post, Zdziarski highlighted Apple’s stance on protecting user data as a big draw to him taking the new job:

This decision marks the conclusion of what I feel has been a matter of conscience for me over time. Privacy is sacred; our digital lives can reveal so much about us – our interests, our deepest thoughts, and even who we love. I am thrilled to be working with such an exceptional group of people who share a passion to protect that.

As Apple-focused publication 9to5Mac noted, some of Zdziarski’s recent high-profile security endeavors included the researcher discovering in 2014 a so-called backdoor in iPhones, which hackers could have exploited if the issue weren’t brought to the limelight.

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Fortune contacted Apple for more information and will update this story if it responds.