Note: During the 2024 Chinese National Day holiday, a piece of news has attracted the attention of the crypto community. HBO is about to broadcast the documentary "Money Electric: The Bitcoin Mystery" on October 8, which is said to reveal who is the founder of Bitcoin, Satoshi Nakamoto.
In the Polymarket market where people in the crypto industry are active, 34% of people believe that Satoshi Nakamoto revealed by the HBO documentary is Len Sassaman, which is much higher than Hal Finney, Blockstream CEO Adam Back and Nick Szabo, the father of smart contracts, who are more famous in the industry.
So who is Len Sassaman? Why do people think Len Sassaman is most likely Satoshi Nakamoto? Evan Hatch, founder of Worlds.org, published an article in 2021 introducing Len Sassaman's life information and the similarities between Len Sassaman and Satoshi Nakamoto. He believes that Len Sassaman is likely to be Satoshi Nakamoto, a direct contributor to Bitcoin.
The original title is "Len Sassaman and Satoshi: a Cypherpunk History". Golden Finance compiled this article to reward readers.
We have lost too many hackers to suicide. What if Satoshi was one of them?
An obituary has been embedded in every node of the Bitcoin network. It is embedded in the transaction data and is a memorial to Len Sassaman, who has essentially been immortalized in the blockchain. In many ways, it is a fitting tribute.
Block 138725
Len is a true cypherpunk - brilliant, uninhibited, and idealistic. He has dedicated his life to defending individual freedom through cryptography, working as a developer of PGP encryption and open source privacy technology, and as an academic cryptographer studying P2P networks under the guidance of blockchain inventor David Chaum.
He is also a pillar of the hacker community: a friend and influencer to many important figures in information security and cryptocurrency history.
Losing Satoshi
Len was said to be on track to become one of the most important cryptographers of his time, but after a long battle with depression and functional neurological disorders, he committed suicide on July 3, 2011 at the age of 31.
His death coincided with the disappearance of the world’s most famous cypherpunk: Satoshi Nakamoto. Just 2 months before Len’s death, Satoshi sent his final communication:
I have moved on to other things and will probably not be here again in the future.
Over the course of a year, Nakamoto committed 169 code and made 539 posts before disappearing without explanation, leaving behind a mountain of unfinished features, heated debate about his vision for Bitcoin, and a $64 billion BTC fortune that remains untapped to this day.
We’ve lost too many hackers to suicide. Aaron Swartz, Gene Kan, Ilya Zhitomirskiy, James Dolan. They are all victims of an epidemic that has cost technological progress itself. Imagine if the creators of Bitcoin had achieved their goals before they died. If that were true, if they were treated with the care and dignity they deserved, what would they have given to the world?
I hesitate to speculate on the identity of Satoshi Nakamoto, as discussions about him are often misleading, or even downright stupid and immoral. However, with Craig Wright’s fraudulent claim to have created Bitcoin, it is worth revisiting the topic and revisiting the cypherpunks who actually created Bitcoin.
Whoever Satoshi Nakamoto was, he “stood on the shoulders of giants” — Bitcoin is the culmination of decades of accumulated research and discussion in the cypherpunk community. In this sense, Len is undoubtedly an indirect contributor. However, one cannot help but wonder who actually wrote the code, ran the first node, and posted under the pseudonym Satoshi Nakamoto.
In order to synthesize and implement the myriad ideas that Bitcoin is based on, that person or group would need to have a unique combination of expertise, spanning public key infrastructure, academic cryptography, P2P network design, practical security architectures, and privacy techniques. They would likely be deeply rooted in the cypherpunk community and adjacent to figures who have had a significant impact on cryptocurrency. Finally, they would need to have the ideological conviction and hacker spirit to “roll up their sleeves” and anonymously build a real-world version of ideas that had previously been relegated to the realm of theory.
When I think about Len’s life, I see many of the same traits, and I think it’s very likely that Len was a direct contributor to Bitcoin.
With the unprecedented attention being paid to cryptocurrency, I hope to shine a spotlight on an unsung hero to whom we owe a debt of gratitude. I also hope we can reflect on the importance of addressing mental illness, especially functional neurological disorders, which deserve more attention.
origin
The
Even at a young age, he was a self-taught technologist with a special interest in cryptography and protocol development. Although he lived in a small town in Pennsylvania, at the age of 18, Len joined the Internet Engineering Task Force, working on the TCP/IP protocol underlying the Internet, and later on the Bitcoin network.
Len, who was diagnosed with depression as a teenager because he was “always a little bit eccentric because he was smart,” unfortunately suffered a traumatic experience at the hands of a “borderline sadistic” psychiatrist, an experience that can make one distrust so-called authority figures.
In 1999, Len moved to the Bay Area and quickly became a fixture in the Cypherpunk community. He roomed with Bram Cohen, the founder of Mojo and Bittorrent, and became a contributor to the legendary Cypherpunk mailing list, where Satoshi first announced Bitcoin. Other hackers remember him as smart and lighthearted, chasing down a squirre at Cypherpunk conferences and speeding around in a sports car with a "Get Out of JaiFree" card on it in case he got pulled over.
In San Francisco, Len works to defend individual freedom and privacy through technology and political direct action. At 21, he made headlines for organizing protests against government surveillance and the jailing of hacker Dmitri Skylarov.
PGP
Early in his career, Len established himself as an authority on public key cryptography (the foundation of Bitcoin). By the age of 22, he was speaking at conferences and had founded a public key cryptography startup with renowned open source activist Bruce Perens.
After the dot-com crash, the startup folded and Len joined Network Associates to help develop PGP cryptography, which is at the heart of Bitcoin. During the 2001 release of PGP7, Len set up interoperability testing for the OpenPGP implementation, which brought him into contact with many important cryptographic pioneers. Len also contributed to the GNU Privacy Guard implementation of OpenPGP and worked with PGP inventor Phi Zimmerman to invent a new cryptographic protocol.
When introducing Bitcoin, Satoshi Nakamoto said that he hoped that Bitcoin could be used "as currency" and use the same strong encryption technology (i.e. PGP) used to protect file security.
A generation ago, multi-user time-sharing computer systems had a similar problem. Before the advent of strong encryption, users had to rely on password protection…
Then strong cryptography became available to the public, and trust was no longer necessary. … Now it’s time we do the same with currency.
Hal Finney
At Network Associates, Len worked with HaFinney on PGP. Finney was the second PGP developer and helped create the RFC 4880 standard for OpenPGP interoperability. He was also the earliest and most important contributor to Bitcoin after Satoshi Nakamoto:
Finney was the first person other than Satoshi Nakamoto to contribute to the Bitcoin code and run a Bitcoin node.
Finney was the first recipient of Bitcoin (sent by Satoshi Nakamoto himself).
Finney invented the concept of Reusable Proofs of Work, upon which Bitcoin mining is based.
Satoshi communicated extensively with Finney long before Bitcoin was released, and in one of his last blog posts, Satoshi publicly paid tribute to Finney.
Not surprisingly, Finney is one of the most popular candidates for Satoshi Nakamoto, even though this meant that Finney faked a lot of his email interactions with Satoshi and contributed to Bitcoin under both his real name and another fake identity. Finney would continue to work on Bitcoin after Satoshi “left” in 2011.
Remailers
Len and Finney have a very rare and relevant skill set: they were both developers of the email-forwarding technology that was a precursor to Bitcoin.
Remailers and cryptocurrencies were both proposed by David Chaum. Remailers are specialized servers for sending messages anonymously or pseudonymously. Their use was common when posting to the Cypherpunk mailing list, which was itself built on top of a distributed mail relay program.
Diagram of a Type II mail forwarder
Early mail forwarders simply forwarded messages while hiding the identity of the sender, while later protocols (such as Mixmaster, the most popular mail forwarder) rely on decentralized nodes to distribute fixed-size encrypted blocks of information on a P2P network. Bitcoin's architecture is very similar to mail forwarders, although its nodes transmit transaction data instead of messages. In 1997, crypto-anarchist founder Tim May even proposed a digital currency based on mail forwarders.
As the lead developer, node operator, and lead maintainer of Mixmaster, Len is a prominent expert in email forwarding techniques. He has also implemented similar techniques as a systems engineer and security architect at Anonymizer.
Email forwarding technology is not only the direct technological forerunner of Bitcoin, but also the foundation of Bitcoin's ideological history. In the article (Why do we need email forwarding programs), Finney believes that email forwarding technology is the foundation of the anonymous digital economy.
Email relay technology represents the "bottom of the road" in this temple of thought, the ability to exchange information privately without revealing our true identity. The way we can transact, show our credentials, and make deals, without a government or corporate database tracking our every move.
One of the cypherpunks’ visions included the ability to transact anonymously using “digital cash”… This is another area where anonymous email plays an important role.
Mail reposting operators were the first to recognize the need for cryptocurrencies: without an anonymous means of payment, mail reposting programs had to be run out of the operator's own pocket. This created scalability issues, and meant that spam and abuse were a constant problem. Because of this, the underlying concepts of many cryptocurrencies stem from the need for an abuse-resistant, for-profit mail reposting program:
In 1994, Finney proposed that mail forwarding programs could be monetized through anonymous "tokens" and "cash tokens."
Smart contracts were first discussed in the context of preventing abuse by mail forwarding programs. Nick Szabo published a prescient paper on smart contracts in 1997, specifically mentioning Mixmaster.
Ian Goldberg and Ryan Lackey (both of whom Len knew) were important figures in the email forwarding community and they were involved in developing an unfinished cryptocurrency called HINDE in 1998. Ian later created several early ecash clients, while Ryan became the CSO of Tezos.
Thus, Satoshi’s second article on Bitcoin states that sending emails for a fee is the first working use case for Bitcoin.
Initially it could be used for proof-of-work applications that are almost, but not quite, free services.
It can already be used to send emails for a fee. The send dialog is resizable and you can enter a message of any length.
Adam Back
One person Len has crossed paths with in the small email forwarding community is Blockstream CEO Adam Back, who was the first person to communicate with Satoshi Nakamoto.
Back's interest in cryptocurrency began when he ran a mail forwarding program, and he created the HashCash proof-of-work system for mail forwarding program operators to combat spam and DDOS attacks. Satoshi later used HashCash as the basis for Bitcoin mining.
We know that Len worked directly with Back, listing him as a contributor to research papers and Mixmaster memos. Both were involved in many OpenPGP implementations and were connected to each other in each other's PGP trust network.
Interestingly, Back himself has suggested that Satoshi may have been a mail forwarder developer, noting that developers would “[practice] their own techniques” to participate anonymously in cryptographic protocol discussions. Unlike many of the Cypherpunks discussed, we know that Len made a number of anonymous contributions to the Cypherpunk mailing list via mail forwarders.
Bram Cohen responded to this article, suggesting that he and Hal Finney may have worked together under pseudonyms
Chaum and COSIC
After graduating from high school, Len worked to support his family and never had the opportunity to go to college. Despite this, in 2004 he landed his “dream job” as a researcher and doctoral student at COSIC, a computer security and industrial cryptography research group at the Catholic University of Leuven in Belgium.
Len’s doctoral advisor at COSIC was none other than David Chaum, the “Father of Digital Currency.” Although Chaum laid the foundation for the entire cypherpunk movement and all cryptocurrencies, few people can say that they have worked directly with him.
Some of Chaum's related achievements:
He invented cryptocurrency in his 1983 paper “Blind Signatures for Untraceable Payments.”
The invention of the blockchain, his 1982 paper detailed the code for all but one element of the blockchain, which is detailed in the Bitcoin white paper.
His company Digicash created the first electronic cash system. Anonymous payments between digital pseudonyms were central to this vision.
“[Chaum] is at the center of a seemingly unstoppable movement: the digitization of money… The wild card in the age of digital money is anonymity, and without it, David Chaum argues, we’re in trouble”
While Digicash failed (in part due to its reliance on a centralized system), Chaum wanted to create a second digital currency that would offer a combination of anonymity and utility.
While many viewed its failure as proof that digital cash was unworkable, Satoshi defended the “old Chaumian money” while acknowledging the problems that came with centralization.
Many people automatically assume that electronic money is doomed to fail because so many companies have failed since the 1990s. I hope people understand that it is the centrally controlled nature of these systems that dooms them to failure.
Len's Research
Len worked at COSIC in Belgium until his death in 2011. During this time he published 45 papers and served on 20 conference committees.
Len's research focuses on developing privacy-enhancing protocols with "real-world applicability" and working code. His main project (assisted by Bram Cohen) is Pynchon Gate, an evolution of mail-forwarding technology that allows anonymous information retrieval through a distributed network of nodes without the need for a trusted third party.
Pynchon Gate and meta index + bucket poo architecture
This work is closely related to Bitcoin - as work on Pynchon Gate progressed, Len became increasingly focused on finding solutions to Byzantine failures (also known as the Byzantine Generals Problem), which had been a major obstacle to early P2P networks.
Schematic diagram of the Byzantine Generals Problem
In the context of distributed computing, Byzantine fault tolerance refers to the ability of a network to remain operational even when nodes are compromised or unreliable. Byzantine faults are one of the biggest problems in implementing secure, decentralized cryptocurrencies without double spending or trusted third parties. Satoshi Nakamoto's most important innovation was the "triple-entry" accounting system, which solved this problem using the blockchain introduced by Chaum.
Len became increasingly active in the field of financial cryptography during the development of Bitcoin between 2008 and 2010. He joined the International Financial Cryptography Association and gave presentations at and served on the committee of the Financial Cryptography and Data Conference. The latter was founded by Robert Hettinga, an early and prominent advocate of digital cash, which was a major topic at the conference.
Satoshi Nakamoto as a Scholar
There are numerous clues that Satoshi Nakamoto worked in academia during the development of Bitcoin, an idea that has been echoed by Gavin Andersen, founder of the Bitcoin Foundation.
“I think he’s an academic, maybe a postdoc, maybe a professor, who just doesn’t want the attention.”
Satoshi's code contributions and comments increased dramatically during the summer and winter breaks, but tapered off in late spring and year-end, when scholars were taking final exams or grading.
The unique structure of Bitcoin's code also suggests that Nakamoto had an academic background. Bitcoin has been described as "brilliant but careless," eschewing traditional software development practices such as unit testing, but displaying a cutting-edge security architecture and an expert understanding of academic cryptography and economics.
Whoever did this has a deep understanding of cryptography… They’ve read the academic papers, they have a sharp intellect, and they’ve brought these concepts together in a really new way.
When renowned security researcher Dan Kaminsky first reviewed Satoshi’s code, he attempted to penetration test it with 9 different vulnerabilities but was surprised to find that Satoshi had anticipated and patched them all.
“I thought of some beautiful bugs, but every time I looked at the code I found a line of code that would solve the problem… I’ve never seen anything like it.”
This may indicate that Satoshi and Kaminsky had shared information security experience and expertise. Coincidentally, Len and Kaminsky co-authored and published a paper demonstrating methods for attacking public key infrastructure.
In addition, the Bitcoin whitepaper was published in a format rarely seen on the Cypherpunk mailing list—a LaTeX-formatted research paper with academic content such as an abstract, conclusion, and MLA citations. In contrast, other proposals such as Bitgold and b-money were unstructured blog posts.
Satoshi Nakamoto in Europe
Since COSIC is headquartered in Leuven, Len lived in Belgium during the development of Bitcoin. This is important because many facts indicate that Satoshi lived in Europe - a major focus of the early investigation.
Satoshi's writing style reflects British English spelling and word choices, such as "bloody hard," "flat," "maths," "grey," and the dd/mm/yyyy date format. However, Satoshi also mentioned the euro instead of the pound.
Bitcoin's genesis block also contains the headline from that day's edition of The Times ("The Times 03/Jan/2009 Chancellor on brink of second bailout for banks"). The headline is unique to the print edition, which is only distributed in the UK and Europe. In 2009, The Times was one of the top ten newspapers in Belgium and was "widely used by academics and researchers due to its wide circulation in libraries and its detailed indexing".
These clues leave us with a paradox: they suggest that Satoshi Nakamoto was European, but the people who possessed the necessary skills and understood the main implications of Bitcoin were most likely Americans. Much of the cypherpunk community coalesced around conferences and meetups, which is one reason why people from the United States, especially San Francisco, are overrepresented. Similarly, jobs that offer access to cutting-edge professional information security and cryptography experience are concentrated in the United States.
Oddly enough, even though Len is American, he speaks exactly the same British English as Satoshi.
Analyzing Satoshi’s posting history, it can be found that he is a European “night owl” who works on Bitcoin after get off work or school during the day. Satoshi also said that the increase in mining difficulty happened “yesterday”, but if he lived in the United States, the situation would be different.
Assuming Satoshi lived a life unrelated to Bitcoin, he was not at his computer at home most of the time during work or school… If Satoshi lived in the BST time zone, he worked most of the time at night, often until the early hours of the morning
When we examined Len’s tweet history, we found that the timestamps of Satoshi’s posts and code commits matched closely with Len’s own late-night activity.
P2P Network
While Bitcoin was not the first cryptocurrency, it was the first cryptocurrency to be based on a fully P2P distributed network. Satoshi Nakamoto stressed the importance of this when he first mentioned Bitcoin:
I have been researching a new electronic cash system that is completely peer-to-peer and does not require a trusted third party.
Dan Kaminsky said that in order to create Bitcoin, Satoshi Nakamoto needed to "understand economics, cryptography, and P2P networks," and Len had an unusually early and in-depth understanding of these three disciplines and their applications in digital currency.
Bram and Len interviewed at CodeCon
While in San Francisco, Len lived and worked with Bram Cohen, the creator of the most widely used P2P protocol, BitTorrent. During this time (2000-2002), Bram developed a revolutionary P2P network called MojoNation, which used the "Mojo Token" digital currency, making it one of the first publicly issued digital currencies.
In MojoNation’s P2P economy, “tokens” can be redeemed for file storage, which will be encrypted and encoded into “blocks” uploaded to a distributed network of nodes hosting a public ledger, reminiscent of Bitcoin’s own distributed bilateral accounting system. Mojo is not just an internal accounting token, but a full currency - it can be redeemed for US dollars and vice versa. Some of the early discussions of token economics involved the mechanics of the Mojo token.
One unit of Mojo represents a portion of the current functionality of the entire system. If you work for me now, I will give you points, and in the future when the network is larger, these points will represent a portion of a larger pie, so when you spend them, their value increases.
Satoshi Nakamoto discussed token economics in a very similar way, citing BitTorrent
For transferable proof-of-work tokens to have value, they must have monetary value. To have monetary value, they must be transferred across a very large network — such as a file-trading network similar to BitTorrent.
Despite its vision, MojoNation’s economy soon collapsed due to hyperinflation. Satoshi Nakamoto consciously designed Bitcoin to avoid this fate by having deflation built in and not relying on a central “coin minting” server.
In 2001, Bram launched BitTorrent. As a P2P alternative to the centralized Napster, BitTorrent foreshadowed Bitcoin’s own distributed node topology and consensus system, as well as the protocol-level incentive system. BitTorrent not only innovated on networks such as Gnutella at a technical level, but also utilized economic incentives and game theory.
Bittorent's design compared to Napster
Len presciently told Bram that “BitTorrent will make him greater than [Napster founder] Sean Fanning.” Satoshi later referenced Napster when explaining the need for a fully decentralized web.
Governments are good at cutting off the leadership of centrally controlled networks like Napster, but pure P2P networks like Gnutella and Tor seem to be able to hold their own.
Coincidentally, Len and Tor founder Roger Dingledine both participated in the development of the Mixminion mail forwarding protocol, spoke together at the Black Hat conference, and co-founded the HotPETS conference.
In 2002, Len and Bram co-founded the CodeCon conference, which focuses on "highly practical projects with useful code". At CodeCon in 2005, Finney introduced reusable proof-of-work via a modified BitTorrent client that sent P2P digital currency. One commentator described it as:
...the world's first transparent server that facilitates a distributed, collaborative world of RPOW servers.
Cryptocurrencies were a hot topic at the inaugural CodeCon, which included a HashCash demo by Adam Back and Zooko’s introduction of Mnet, the fully open-source and decentralized successor to MojoNation. Mojo is not affiliated with any one company and can be independently audited, both of which Satoshi considered critical.
Mnet client screenshots
MojoNation co-founders Zooko Wilcox and Jim McCoy also became an inspiration to Bitcoin and cryptocurrency pioneers. Zooko was one of Satoshi’s first collaborators and an employee of David Chaum at Digicash, and Satoshi included a link to Zooko’s blog when Bitcoin v0.1 was released on Bitcoin.org. Zooko later founded Zcash, a major privacy-focused cryptocurrency. He created the often-discussed “Zooko’s Impossible Trinity” framework.
“Zooko’s Trilemma is a trilemma of three properties that the names of participants in a network protocol are often thought to possess”
McCoy is also a major influencer in the cryptocurrency space, and Ryan Selkis of DigitaCurrency Group said he believes McCoy could be Satoshi Nakamoto.
Hacktivism
Even by the standards of the cypherpunk community, both Len and Satoshi had particularly strong ideological beliefs and commitments to open knowledge.
I wish you would stop talking about me... maybe talk about open source projects and give more credit to your developers
Satoshi’s “hacktivist” approach to distributing Bitcoin through free, open-source grassroots projects stood in stark contrast to their predecessors. Chaum, Stefan Brand, eCash, and others took a radically different approach: filing patents, forming closed-source venture capital firms, and trying to drive adoption through corporate partnerships.
This is similar to Len's extensive contributions to open source projects such as PGP, Mixmaster, GNU Privacy Guard, and his extensive volunteer experience in groups such as the Shmoo Group.
In response to this story, Bram said Len preferred to post anonymously
Nakamoto has hinted at his ideological leanings several times, saying Bitcoin is "very attractive to libertarian views" and could "win a major battle in the arms race and gain a new free territory within a few years."
Len is equally passionate about defending open knowledge and technological progress from interference from corporations and governments.
The pursuit of knowledge is a fundamental part of being human. Any kind of prior restriction is, in my opinion, an infringement on our freedom of thought and consciousness. So not only do I want us to avoid overly restrictive knee-jerk legislation… I don’t want to see anyone build a framework that could be misused for that purpose.
Conclusion
Just as Satoshi created Bitcoin under a pseudonym, Len was in a sense forced to live under his persona. After an accident in 2006, Len's non-epileptic seizures and functional neurological problems worsened, exacerbating the depression he had been battling since his youth.
As a victim, Len “felt like he had to keep up the facade of being this super-capable guy” and was “terrified” that his failing health would end his work and disappoint the people he cared about.
Despite these challenges, Len continued to work until a few months before his death, contributing to papers and even giving a lecture at Dartmouth. Tragically, he successfully concealed the severity of his situation from almost everyone in his life.
Few knew the extent of it… One thing I heard repeatedly was “we never knew, it looked like he was doing fine”.
Len spoke at Dartmouth shortly before his death
As Len built on the ideas that came before him, one gets the sense that he was committed to building something that would outlast him, which is one reason for his commitment to open source and open knowledge.
This is our legacy, our research and ideas, which will lead to knowledge that humans have never had the opportunity to obtain in history, and we will pass this knowledge on to future generations. We need to make sure that we don't get stuck in a situation where we can't share our research with others, and that it doesn't get locked away in the vaults of intellectual property lawyers.
Len’s death in 2011 was a huge loss for the cypherpunks and the tech community in general, a fact reflected in the outpouring of memories and sympathies that followed. One comment that stood out to me was a post on Hacker News by “pablos08”:
Len and I became friends, as co-participants in the cypherpunks back in the day, when it was still a wild frontier. We reimagined our world, a world filled with cryptographic systems that would mathematically enforce the freedoms we cherished. Anonymous mail forwarders would protect speech from retaliation; The Onion Router would ensure that no one could censor the internet; digital cash would enable a completely free economy. We had plans to decentralize and distribute everything.
We imagine complex and esoteric threats to future problems - and we design future protocols to defend against them. All of this is a geeky utopian academic exercise. I tend to keep it that way, but Len wants to get his hands dirty.
Cypherpunks write code.