As an active member of cypherpunk, a believer and student of David Chaum, the father of cryptocurrency, and a friend and collaborator of BT and Chia founder Bram Cohen, Len has made outstanding contributions to the encryption field in just a dozen years. Whether he is Satoshi Nakamoto is not important anymore. What is important is that through this article, we can touch on the past of Bitcoin, understand the original intention of Bitcoin and those people and things.
We've lost too many suicide hackers. What if Satoshi Nakamoto is one of them?
An obituary is permanently recorded on every node of the Bitcoin network. This is a tribute to Len Sassaman, immortalized in the blockchain itself. In more ways than one, it's a fitting tribute.
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Len is a true cypherpunk: talented, bohemian, and idealistic. He has dedicated his life to defending individual freedom through cryptography, a developer of PGP encryption and open source privacy technologies, and a cryptographer studying P2P networks under the leadership of blockchain inventor David Chaum.
He is also a pillar of the hacker community: a friend and influence to many important figures in the history of information security and cryptocurrency.
lost Satoshi Nakamoto
By all accounts, Len was poised to become one of the foremost cryptographers of his time. But on July 3, 2011, he tragically committed suicide at the age of 31 after a long battle with depression and functional neurological disorders.
His death coincided with the disappearance of the world's most famous cypherpunk, Satoshi Nakamoto. Just 2 months before Len passed away, Satoshi Nakamoto sent his final message:
I've moved on to other things and probably won't be in the future
I’ve moved on to other things and probably won’t be around in the future.
After 169 code commits and 539 posts in a year, Satoshi disappeared without explanation. He left behind a litany of unfinished business, a raging debate about people's vision for bitcoin, and a $64 billion fortune in bitcoin that remains untouched.
We've lost too many hackers to suicide: Aaron Swartz, Gene Kan, Ilya Zhitomirskiy, James Dolan. They are all victims of a stigma that does great harm to technological progress itself. Imagine if the creators of Bitcoin died before they could see it - if that's true - what would they do to the world if they got the attention and respect they deserve?
I'm hesitant to speculate on the identity of Satoshi Nakamoto, as discussions tend to range from misleading to downright deceitful and unethical. But with Craig Wright fraudulently claiming credit and claiming copyright to the Bitcoin white paper, it's worth revisiting the topic and focusing the discussion on the cypherpunks who actually built Bitcoin.
No matter who Satoshi Nakamoto is, they are all "standing on the shoulders of giants". Bitcoin is the crystallization of research and discussions accumulated by the cypherpunk community for more than ten years. In this sense, Len is certainly an indirect contributor. However, one cannot help but wonder who actually wrote the code, ran the first node, and released it under the pseudonym of Satoshi Nakamoto.
To synthesize and realize the myriad ideas of Bitcoin, this person or group of people requires a unique combination of expertise, including knowledge of public-key cryptography, cryptography, P2P networks, practical security architectures, and privacy techniques. They may have been deeply entrenched in the cypherpunk community and in close contact with figures who have proven to have significant influence on cryptocurrencies. Finally, they need ideological conviction and hacker spirit to"roll up your sleeves", anonymously building a real-world idea that had previously been relegated to the realm of theory.
When I look at Len's life, I see many of these traits in common, and I think it is indeed possible that Len was a direct contributor to Bitcoin.
Given that cryptocurrencies are receiving unprecedented attention, I wish I could draw attention to a"unsung hero"origin
origin
As a young man, Len was a self-taught technologist with a penchant for cryptography and protocol development. Although living in small town Pennsylvania, at the age of 18 Len joined the Internet Engineering Task Force, responsible for the development of the TCP/IP protocol for the Internet and later the Bitcoin network.
"Always a bit of a weird kid because he's so smart", Len was diagnosed with depression as a teenager. Unfortunately, he was"Sadist"Traumatic experiences at the hands of typical psychiatrists can create distrust of so-called authority figures.
In 1999, Len moved to the Bay Area and soon became a regular in the cypherpunk community. He moved to Bram Cohen, the creator of Mojo and Bittorrent, and was a contributor to the legendary cypherpunk mailing list where Satoshi Nakamoto first announced Bitcoin. Other hackers remembered him as a bright and light-hearted guy who chased a squirrel at a cypherpunk meeting, raced around in a sports car, and carried a"Get Out of Jail Free"cards to prevent being blocked.
In San Francisco, Len works to defend individual liberty and privacy through technological and political direct action. At 21, he was making headlines for organizing protests against government surveillance and the jailing of hacker (Dmitri Skylarov).
PGP
Early in his career, Len emerged as an authority on public-key cryptography -- the foundation of Bitcoin. At 22, he spoke at various conferences and started a public-key encryption startup with prominent open-source activist Bruce Perens.
After the startup collapsed due to the dot-com bubble, Len joined Network Associates to help develop the heart of Bitcoin: PGP encryption. When PGP7 was released in 2001, Len established interoperability tests for the OpenPGP implementation, putting him in contact with many important cryptographic pioneers. Len also contributed to the GNU Privacy Guard implementation of OpenPGP and collaborated with PGP inventor Phil Zimmerman on a new encryption protocol.
When introducing Bitcoin, Satoshi Nakamoto said he wanted Bitcoin to become the"currency same thing", he wrote in an email:
A generation ago, multi-user time-sharing computer systems had similar problems. Before strong encryption, users had to rely on password protection...
Then, strong encryption starts to become accepted by the masses, and trust is no longer necessary. It is time we do the same with money.
Hal Finney
At Network Associates, Len worked on PGP with Hal Finney. Finney was the second PGP developer and helped create the RFC 4880 standard to enable OpenPGP interoperability, and he is 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 proof-of-work on which Bitcoin mining is based.
Satoshi corresponded extensively with Finney even before Bitcoin was released. In their final post, Satoshi openly expressed his respect for Finney.
Unsurprisingly, Finney was one of the most popular candidates for Satoshi, although this meant that Finney faked his numerous email interactions with Satoshi, using both his real name and a separate pseudonym Bitcoin contributes. In 2011 Satoshi Nakamoto"career change"Since then, Finney has continued to work on Bitcoin.
Remailers
Len and Finney have a very rare related skill: they are both the predecessors of Bitcoin"mail forwarder"developers.
image description
Schematic diagram of a transponder
Early forwarders simply forwarded messages while hiding the identity of the sender, while later protocols such as Mixmaster relied on decentralized nodes to distribute fixed-size chunks of encrypted messages on a P2P network. Bitcoin's architecture is very similar to that of a transponder, although its nodes are used to transmit transaction data rather than information. In 1997, Crypto-anarchist founder Tim May even proposed a digital currency built on transponders.
As the main developer, node operator and main maintainer of Mixmaster, Len is a well-known expert in forwarding email technology. He also implemented similar techniques as systems engineer and security architect for Anonymizer Privacy Protection.
Forwarding technology is not only the direct technical ancestor of Bitcoin, but also the foundation of Bitcoin. exist"why email"In one article, Finney argues: Email is the foundation of an anonymous digital economy, writing:
Forwarding technology represents the idea of"bottom layer", the ability to exchange information privately without revealing our true identities. In this way, we can participate in transactions, display credentials, and transact without government or corporate databases tracking our every move.
A cypherpunk's vision involves using"digital cash"The ability to participate in transactions anonymously. This is another important area for anonymous mail.
Transponder operators were some of the first to recognize the need for cryptocurrencies: without the means to make anonymous payments, operators would have to shoulder operating costs altruistically. This creates scalability issues and means issues like spam and abuse. Because of this, many fundamental concepts of cryptocurrencies come from this need, such as:
and"Token"and"cash token"to achieve monetization.
Smart contracts were first discussed in the context of preventing forwarders from misusing resources. Mixmaster was specifically mentioned in Nick Szabo's 1997 forward-looking paper on smart contracts.
Ian Goldberg and Ryan Lackey (both whom Len knew) were major figures in the forwarding technology community, working on an unfinished cryptocurrency called HINDE in 1998. Ian later helped David Chaum develop several early Ecash clients, and Ryan later became the CSO of Tezos.
In his second article on Bitcoin, Satoshi Nakamoto said:
Paying to send emails was the first use case for Bitcoin.
Initially it can be used for proof-of-work applications, for services that are almost free but not completely free.
It can already be used to send emails for a fee. The send dialog is resizable, and you can enter a message of the length you like.
Adam Back (Adam Back)
Intersecting with Len in the cypherpunk mailing list community is Blockstream’s CEO Adam Back — the first person to communicate with Satoshi Nakamoto.
Adam's own interest in cryptocurrencies began with running a transponder, and he created the HashCash proof-of-work system for transponder operators to combat spam and DDOS attacks. Satoshi Nakamoto later used HashCash as the basis for Bitcoin mining.
We know that Len worked directly with Back, listing him as a contributor to a research paper as well as a Mixmaster memo. Both have been involved in many OpenPGP implementations and are associated in each other's PGP network of trust.
Interestingly, Back himself said that Satoshi Nakamoto may have been the developer of a mail forwarder, noting that the developer would"[Practice] their own technique"Come and contribute to the discussion of encryption protocols.
Unlike many of the cypherpunks in question, we know that Len made numerous pseudonymous contributions to cypherpunk mailing lists via mail forwarders.
(Bram Cohen's response to this article, suggesting that he and Hal Finney may have collaborated anonymously)
David Chaum & COSIC
After high school, Len worked to support his family and never had the opportunity to attend college. Nevertheless, he found his research in 2004 at the Computer Security and Industrial Cryptography Research Group (COSIC) at KU Leuven, Belgium."dream job", as a researcher and doctoral student.
Len's doctoral supervisor at COSIC is"father of digital currency"David Chaum. While Chaum laid the groundwork for the entire cypherpunk movement and all cryptocurrencies, few can claim to have worked directly with him.
Some of David Chaum's accomplishments include:
Invented cryptocurrencies in his 1983 paper "Blind Signatures for Untraceable Payments".
Invented the blockchain, his 1982 thesis laid out all the important elements of the blockchain that were later mentioned in the Bitcoin white paper.
Founded Digicash Corporation and created the first electronic cash system. Anonymous payments are at the heart of this vision.
"David Chaum stands in a movement that seems unstoppable: the digitization of money, a common feature of the digital currency age is anonymity, without which David Chaum argues we are in trouble"
While Digicash failed (due in part to its reliance on centralized systems), David Chaum is creating a second digital currency, xx coin, that attempts to offer a combination of anonymity, utility, and quantum-resistant properties.
While many see its failure as proof that digital cash is not viable, Satoshi Nakamoto"Old Chaumian Currencies"defense, while acknowledging the problems caused by centralization. Satoshi Nakamoto mentioned in the email:
A lot of people automatically see e-money as a lost venture because all the companies have failed since the 1990s. I hope it's clear that it's just the centralized nature of those systems that doom them to failure.
Len's research
Len worked at COSIC in Belgium until his death in 2011. During this time, he has amassed an impressive 45 papers and 20 conference committee positions.
Len's research has focused on developing"real world applicability"image description
(Pynchon Gate and meta-index+bucket pool architecture)
This work was very relevant to Bitcoin: as work on Pynchon Gate progressed, Len increasingly focused on finding a solution for Byzantine fault tolerance (aka the Byzantine Generals Problem), which had been a major obstacle in early P2P networks.
In the context of distributed computing, Byzantine Fault Tolerance (BFT) refers to the ability of a network to remain functional in the event of nodes being corrupted or unreliable. Byzantine failures are one of the biggest problems that need to be solved for a secure, decentralized cryptocurrency that has no double spending and doesn't require trusting third parties. Satoshi Nakamoto's most important innovation is the use of the blockchain introduced by David Chaum"triple"The accounting system, solves this problem.
During the development of Bitcoin in 2008-2010, Len became increasingly active in financial cryptography. He is a member of the International Association for Financial Cryptography and has spoken at conferences on Financial Cryptography and Data, where he also serves on committees. The latter was founded by Robert Hettinga, an early and prominent advocate of digital cash, and it was a major topic at the conference.
Satoshi Nakamoto as a scholar
There are many clues that Satoshi Nakamoto has been working in the academic field during the development of Bitcoin, an idea supported by Bitcoin Foundation founder Gavin Andersen (Gavin Andersen), who said:
"I think he's an academic, maybe a postdoc, maybe a professor, he just doesn't want the attention"。
Satoshi's code contributions and comments ramp up during summer and winter breaks, but taper off in late spring and year-end, when an academic should be taking final exams and/or being graded.
The figure below shows the speaking frequency of Satoshi Nakamoto on bitcointalk.org
The specific construction of the Bitcoin code also shows that Satoshi Nakamoto has an academic background, and the code quality is considered"smart but sloppy", he abandoned traditional software development practices such as unit testing, but demonstrated top security architecture and professional understanding of cryptography and economics.
Whoever did it had a deep understanding of cryptography...they'd read the academic papers, they had a sharp intellect, and they combined the concepts in a really new way.
When the famous security researcher Dan Kaminsky first audited Satoshi Nakamoto's code, he tried to test it from 9 different security points, but was surprised to find that Satoshi had already All such possible vulnerabilities are foreseen and patched.
"I've come up with a lot of nifty bugs, but every time I go to the code, there's a line that fixes this... I've never seen anything like it."
This may indicate that Nakamoto and Kaminsky have a common set of information security experience and expertise. Coincidentally, Len and Kaminsky co-authored and submitted a paper demonstrating a method for attacking public key infrastructures.
Additionally, the Bitcoin whitepaper is published in a format rarely seen on cypherpunk mailing lists: a LaTeX-formatted research paper with academic features such as an abstract, conclusions, and MLA citations. Other proposals on mailing lists, such as Bitgold and b-money, are 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 some facts suggest that Satoshi was in Europe, which was the main focus of the New Yorker's earlier investigation.
Satoshi Nakamoto's writing shows the spelling and word choice characteristics of British English, such as"blood difficult"、"flat"、"maths"、grey", and a date format of dd/mm/yyyy. Also, Satoshi used Euros instead of British Pounds.
Bitcoin’s genesis block also included a headline from the Times of the day ("The Times 03/Jan/2009 Chancellor on brink of second bailout for banks"). This title is exclusive to the print edition, and it's only released in the UK and Europe. In 2009, The Times was the top ten newspaper in Belgium,"Heavily used by scholars and researchers due to its wide circulation in libraries and detailed indexing"。
These clues leave us with a paradox: it suggests that Satoshi was European, but the people with the requisite skills and exposure to Bitcoin’s major influences are likely to be American. Much of the cypherpunk community comes together through conferences and meetups, which is why a lot of people come from the US, especially San Francisco. Jobs where one is to gain state-of-the-art professional information security and encryption experience are also concentrated in the United States.
Curiously, despite being American, Len uses the same British English as Satoshi. See below:
Analysis of Satoshi Nakamoto's Posting History Shows He Was European"owl"yesterday"yesterday", which is not true if they live in the US.
Assuming Satoshi lived a life outside of Bitcoin, say during work/school, when he was largely away from his computer at home... If Satoshi lived in BST, he worked mostly at night, often Work until the wee hours of the morning.
P2P network
P2P network
While not the first cryptocurrency, Bitcoin is the first digital currency based on a fully P2P distributed network. The importance of this was emphasized when Satoshi Nakamoto first mentioned Bitcoin.
I've been working on a new electronic cash system that is completely peer-to-peer with no trusted third parties.
In order to build Bitcoin, Dan Kaminsky said Satoshi Nakamoto needed"Learn about economics, cryptography, and P2P networks"image description
(Comparison between BT and Napster in terms of design)
Len presciently tells Bram:"BitTorrent Will Make Him Greater Than Napster Founder Sean Fanning". Satoshi later also referred to Napster when explaining the need for a fully decentralized web:
Governments are good at chopping off the heads of centrally controlled networks like Napster, but pure P2P networks like Gnutella and Tor seem to be holding their own.
Coincidentally, Len and Tor founder Roger Dingledine both worked on the Mixminion remailer protocol, co-speaked at Black Hat, and co-founded the HotPETS conference.
In 2002, Len and Bram co-founded a conference called CodeCon that focused on"Implement highly functional projects with code". At CodeCon 2005, Hal Finney introduced reusable Proof of Work (Proof of Work) through a modified BitTorrent client, and sent P2P digital currency through the client.
One reviewer described this as:
...the world's first transparent server that facilitates a distributed, cooperative network of RPOW servers.
image description
(Screenshot of Mnet client)
MojoNation co-founders Zooko Wilcox and Jim McCoy have also proven to be an inspiration to Bitcoin and cryptocurrency pioneers. When releasing Bitcoin v0.1 on Bitcoin.org, Satoshi Nakamoto included a Zookoblog link. Zooko later founded Zcash, a privacy-focused cryptocurrency. He created the oft-discussed"image description"frame
(Len gave a lecture at Dartmouth shortly before his death)
Just as Len builds on his previous ideas, one can feel that he's committed to building something that outlasts him, which is one of the reasons he's committed to open source and open knowledge.
This is our legacy, these studies of ours, these ideas of ours, are leading to knowledge that no human in history has had the opportunity to have, and this is what we want to pass on to future generations. We need to make sure that we're not pushed into a corner where we can't disseminate this research to others, that it's not locked away in an intellectual property lawyer's safe.
When Len passed away in 2011, it represented a huge loss for the cypherpunks and the tech community in general, a fact reflected in the flood of memories and condolences that followed. One comment stuck out to me: Hacker News post from pablos08:
I became friends with Len, we were both cyberpunks and it was a crazy field at the time. We are reimagining our world, filled with cryptographic systems that will mathematically enforce our cherished freedoms. Forward mail anonymously, to preserve speech without fear of reprisal; The Onion Router, to ensure that no one can censor the internet; Digital cash, to enable a radically free economy. We plan to decentralize and distribute everything.
We imagine complex and esoteric threats to solve problems we may one day encounter; we construct futuristic protocols to defend against them. All of this is a highly academic geeky utopian activity. I tend to keep it that way, but Len wants to get his hands dirty.
Cypherpunks write Code.
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Original link: https://leung-btc.medium.com/len-sassaman-and-satoshi-e483c85c2b10
