I recently saw that HBO released a documentary about the true identity of Satoshi Nakamoto, the anonymous creator of Bitcoin. The usual suspects are there: Hal Finney, Dorian Nakamoto, Nick Szabo, Adam Back. But there is one name that constantly appears in predictions and that almost no one mentions: Len Sassaman.

Who exactly is Len Sassaman and why does his name keep resurfacing in these discussions is something I’ve found quite intriguing. It turns out this guy was a serious cryptographer, one of those who truly built the internet as we know it.

The story begins in the cyberpunk community of the late 90s. Len arrived in San Francisco when he was just a teenager, already a self-taught expert in cryptography. He quickly connected with the most important hackers of the time. Lived with Bram Cohen, the creator of BitTorrent, and actively participated in cyberpunk mailing lists where Satoshi first announced Bitcoin. This is no small coincidence.

What’s interesting is that Len Sassaman worked on technologies that are practically the direct ancestors of Bitcoin. He was the lead developer of Mixmaster, an anonymous relaying system that allowed messages to be sent without revealing identity. This is not just a technical detail, it’s fundamental. Bitcoin operates similarly to these relays: instead of transmitting messages, it transmits transactions. The architectural similarity is too close to ignore.

Additionally, Len Sassaman worked extensively with Hal Finney on PGP, the encryption that revolutionized digital privacy. Finney was the first contributor to Bitcoin after Satoshi, received the first Bitcoin transaction, and invented the concept of reusable proof of work on which mining is based. Both shared a very particular skill: they deeply understood P2P decentralized networks, academic cryptography, and privacy systems. Exactly what you would need to build Bitcoin.

In 2004, Len Sassaman achieved what he called “his dream job”: working as a doctoral researcher at COSIC, the Belgian university led by David Chaum, the father of cryptocurrencies. Chaum invented blind signatures, blockchain, and practically everything Bitcoin needed in theory. Few can say they worked directly with him. Len did.

Now, here’s where things get curious. During Bitcoin’s development between 2008 and 2010, Len Sassaman was increasingly active in financial cryptography. He attended international conferences on the topic, participated in committees. And during this same period, Satoshi was developing Bitcoin.

There’s evidence that Satoshi was probably an academic. His code contributions increased significantly during summer and winter vacations, but decreased during final exams. Bitcoin’s code was described as “brilliant but not rigorous,” exactly like the work of someone with academic training but not following conventional development practices. When security researcher Dan Kaminsky reviewed Satoshi’s code, he tried to attack it nine different ways, and Satoshi had anticipated and fixed each of those problems. Coincidentally, Len Sassaman and Kaminsky were co-authors of a paper on methods to attack public key infrastructure.

The geographic fit is also compelling. Satoshi wrote in British English, mentioned the euro, and the genesis block cited a headline from The Times on January 3, 2009, which was only circulated in the UK and Europe. Len Sassaman was living in Belgium during Bitcoin’s development. Analyzing Satoshi’s posting times suggests he was a “European night owl,” working mainly after hours. Satoshi’s posting times suspiciously align with Len’s nocturnal activity.

But here’s the sad part. On July 3, 2011, Len Sassaman took his own life at age 31 after battling severe depression and neurological deterioration. Two months earlier, Satoshi sent his last message: “I’ve moved on to other things and may not be around anymore.” After that, he disappeared completely.

It’s disturbing to think about. We’ve lost too many hackers to suicide. Aaron Swartz, Gene Kan, Ilya Zhitomirskiy. All victims of depression and pressure. What if the creator of Bitcoin was one of them? What if Len Sassaman, who dedicated his life to defending individual freedom through cryptography, was the one who built the system now worth trillions?

What’s certain is that Len Sassaman was a crucial indirect contributor. He worked on precursor technologies, knew the right people, had the exact experience needed, and lived in the right place at the right time. Whoever Satoshi is, he’s undoubtedly “standing on the shoulders of giants,” and Len was definitely one of those giants.

His legacy is literally embedded in Bitcoin. In every network node, there’s an obituary dedicated to Len Sassaman. It’s a perfect monument for someone who built tools of freedom in the shadows. He spent his life defending open knowledge, privacy, and decentralization. Whether he was Satoshi or not, the truth is Bitcoin never would have existed without people like him.