Security engineer, digital rights activist, AI safety and policy researcher. Beloved in these communities.

Eckersley is most famous as an advocate/developer at the intersection of tech and legal activism. His work on the Let's Encrypt free certificate authority, HTTPS Everywhere, and the SSL Observatory made the internet significantly less terrible. Mizza:

Let's Encrypt is something we all came to take for granted very quickly, but lots of us remember when getting an SSL certificate was an expensive and tedious process. Deprecating a billion dollar industry overnight and providing better security for internet users everywhere is a hell of a legacy to leave behind, and I hope one that will be an inspiration for generations to come.

He identified "device fingerprinting" as a major privacy hole and spent a long time trying to mitigate it. His PhD thesis was a characteristic mix of software engineering, economic theory, and law. We'd call it Web3 these days.

He was the 8th person ever to take the GWWC pledge. A few places say he was on the board of CEA US at some point.

Around 2017 he went into AI risk. His work bridged AI ethics and AI safety, covering recidivism prediction, self-driving carssecurity against ML hacking, and military AI but also big-brain topics like impossibility theorems in social choice and ML, the cybersecurity implications of emulated minds, and the queer theory of human alignment. At the end, he was running the AI Objectives Institute (notable for mobilising people already concerned about corporate maximisation) and mentoring for PIBBSS. He was on many of the big "technical AI policy" papers of the last few years. The Alignment Problem is dedicated to him, after he convinced his friend Brian Christian of it.

During covid he worked intensely on private contact tracing algorithms. More than one notable service could not have been done without him.

He received a cancer diagnosis a week before his death. A minor consolation of dying in the present age is people telling beautiful stories about you for strangers and for posterity. So you can know that he was fluent in French, that he organised guerilla meetups, that he was an avid cyclist, that he was a memorable remedial teacher of programming. This is an Eckersley quotes account. Similarly, I can tell you he was writing code until one month before his death. He lived sans LinkedIn.

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Due to the sudden work of unsung heroes, he was cryopreserved despite not having been signed up at the time of his deänimation.

A Wikipedia page was created about him.

Collection of eulogies for Peter, found on Twitter: (non-exhaustive, last updated Sep 5)

I interviewed Peter for Wave in 2016. He blew us all away with his extensive knowledge. He didn't take the job but he's done some amazing work. Since meeting him he also introduced me to several people who we either hired or became good friends with. He was an incredibly nice guy who cared so much about the world and made a big impact on me. Incredibly sad news. 😭

I first met Peter at an event I organized in 2018 on AI safety. I found him to be a direct, fresh, and generous human. Last time we discussed was at EAG in late July. After syncing up our respective histories, we shared on active/potential projects - doing so I felt cherished by his enthusiasm and great feedback. He surprised me by holding the full conversation in French. I wish for his recent project, the AI Objectives Institute, to live on and be positively transformative.

I knew Peter way way way back when we both volunteered at Computerbank Victoria refurbishing  machines and provisioning them with Linux for Low Income and Unwaged folks.
Passionate and possessed of Clear Vision.

Thank you for the post.

I didn't know Peter played such an important role in Let's Encrypt. I will think of him when I'm waiting just a few seconds for new SSL certs to be issued.

Securing websites before Let's Encrypt was not fun.

For example, there was a period where the WP Engine dedicated server for was not using Let's Encrypt, for reasons out of my control. The server was managed by WP Engine, and issues relating to SSL renewal caused the three most severe website outages we had since 2014 (when I started running the site). Thankfully we're now using Let's Encrypt—zero SSL issues since the switch.

I was incredibly sad when I heard he passed away and only heard of his Let's Encrypt work when I saw a eulogy for Eckersley on the front page of HackerNews the day after his passing.

We met at his home in San Francisco and ended up having a wonderful discussion about AI safety and how to use incentive-based governance mechanisms in a holistic complex model of society to align decision-makers. He had a wonderfully inquisitive and original mind with an amazing person inhabiting it and will always have a positive impact on the safety of our future.

Thank you for posting this, Gavin. For the title, Facebook says he was born June 15, 1979.

I’m stunned and heavy with the loss of such a wonderful man.


The irony of you and me is that we're digging around in a privacy advocate's data exhaust. But at least it's out of love.

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