His Code Backs Up the World. Now the Internet Wants Him Flogged. | by Can Artuc | Jun, 2026 | MediumSitemapOpen in appSign up<br>Sign in

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His Code Backs Up the World. Now the Internet Wants Him Flogged.

He returned from retirement to save the code under every backup on Earth. The people he protects turned on him for how he did it. He has no regrets.

Can Artuc

12 min read·<br>2 days ago

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Photo by Cord Allman on UnsplashHis code runs the backups on nearly every Linux server on Earth, and the sync algorithm he invented rides inside macOS, too. He is retired, and he would rather be out sailing.<br>Instead, his inbox keeps filling with security reports for rsync , the software he wrote three decades ago. Most of the reports are machine-generated noise. A few are real. He has to read each one to find out which.<br>So he picked up the same kind of tool that was burying him, and he turned it on the problem.<br>It worked…<br>But within days, the same people who depend on his code wanted him punished for how he’d done it.<br>The 1996 Algorithm Hiding in All Your Backups<br>In 1996, a doctoral student at the Australian National University had a problem that sounded boring and turned out to be everywhere. How do you copy a changed file across a slow connection without sending the whole thing again?

Written by Can Artuc<br>8.9K followers<br>·6 following

The architect, dad. 20+ years in tech. I only write experience-backed stories about Linux and open source. E-mail: c@canartuc.com. More articles: canartuc.com

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