Stefan Thomas is a German software developer and entrepreneur who played a significant role in early Bitcoin education and adoption. He created the widely viewed "What is Bitcoin?" explainer video and BitcoinJS, the first JavaScript implementation of Bitcoin cryptography. He later became CTO of Ripple Labs and co-created the Interledger Protocol. He is also known for one of the most widely reported stories in Bitcoin history: the loss of the password to an IronKey hardware-encrypted drive containing 7,002 BTC.
Early Bitcoin Contributions
In 2011, Thomas created the animated explainer video "What is Bitcoin?" which became one of the first viral resources introducing the general public to Bitcoin. The video was hosted on WeUseCoins.com, a website Thomas founded that became one of the largest Bitcoin information hubs for newcomers at the time. The video's clear, accessible explanation helped millions of people understand the concept of decentralized digital money for the first time, and it is credited with meaningfully accelerating early Bitcoin adoption.
Thomas also created BitcoinJS, the first implementation of Bitcoin cryptography in JavaScript, making it possible to work with Bitcoin in web browsers. BitcoinJS became a foundational library used by numerous blockchain companies and projects, extending Bitcoin's developer ecosystem beyond its original C++ codebase.
Ripple and the Interledger Protocol
In 2012, Thomas moved to the United States and joined Ripple Labs (then OpenCoin) as one of its earliest employees, eventually rising to the position of Chief Technology Officer. At Ripple, he worked on cross-border payment protocols that aimed to connect different payment networks.
During his time at Ripple, Thomas co-created the Interledger Protocol (ILP), an open protocol suite for sending payments across different ledgers and payment networks. ILP was designed as a neutral, ledger-agnostic protocol -- analogous to the Internet Protocol (IP) for data, but for money. The protocol enables interoperability between payment systems that would otherwise be unable to communicate, from traditional banking networks to blockchain systems.
Thomas also contributed to Mojaloop, an open-source software platform for financial inclusion built on Interledger concepts, which has been deployed in multiple countries to enable mobile payments for the unbanked.
Coil and Web Monetization
After leaving Ripple, Thomas co-founded Coil in 2018, a startup built on the concept of web monetization. Coil aimed to create a "subscription to the whole web" -- users paid a flat monthly fee, and Coil would stream micropayments to content creators in real-time as users browsed their content, powered by the Interledger Protocol.
Coil also developed the Web Monetization standard, a proposed browser API that enabled websites to receive streaming payments without ads or paywalls. Over the course of its approximately five years of operation, Coil processed roughly 78 billion payments over Interledger, providing one of the first large-scale proofs-of-concept for the technology.
Thomas later worked on Dassie, an open-source, peer-to-peer implementation of Interledger, and served as Chairperson of the Board at the Interledger Foundation.
The Lost IronKey
Thomas's most widely reported story involves 7,002 bitcoins that he received in 2011 as payment for creating the "What is Bitcoin?" video. At the time, the bitcoins were worth approximately $2,000 in total. Thomas stored the private keys on an IronKey -- a hardware-encrypted USB drive with military-grade security features.
Thomas wrote the password on a piece of paper, which he subsequently lost. The IronKey has a strict security mechanism: after 10 incorrect password attempts, the device permanently destroys all data stored on it. By January 2021, when the story became global news through a New York Times article, Thomas had already used eight of his ten attempts. With only two guesses remaining, the risk of permanently losing the funds has prevented further attempts.
The value of the locked bitcoins has fluctuated dramatically. When the story first gained widespread attention in 2021, the 7,002 BTC were worth approximately $220 million. At various points since, their value has exceeded $700 million.
In 2023, cybersecurity firm Unciphered announced that they had developed a method to bypass the IronKey's self-destruct mechanism, potentially allowing unlimited password attempts. They reached out to Thomas offering to help recover the bitcoins. However, Thomas declined, reportedly citing a prior verbal agreement with other teams who were already working on the problem. As of late 2025, no public confirmation exists that the wallet has been successfully accessed, and the IronKey reportedly remains stored in a secure vault in Switzerland.
Significance
Stefan Thomas's story touches on multiple threads in Bitcoin's history. His "What is Bitcoin?" video represents one of the most successful early efforts to explain Bitcoin to a general audience. BitcoinJS extended Bitcoin's technical reach to the web development ecosystem. His work on Interledger represents an ambitious attempt to solve the problem of payment interoperability at a protocol level.
But it is the IronKey story that has made Thomas perhaps the most cited cautionary example in cryptocurrency of the importance of key management and backup. The image of hundreds of millions of dollars locked behind a forgotten password on a device that will self-destruct after two more wrong guesses has become a defining parable of Bitcoin's early era -- a vivid illustration of both the radical self-sovereignty and the unforgiving responsibility that Bitcoin's design demands of its users.
External Links
- Stefan Thomas on LinkedIn
- Stefan Thomas on GitHub
- Interledger Foundation
- Coil
- BitcoinJS on GitHub
- NYT: Lost Passwords Lock Millionaires Out of Bitcoin Fortunes
References
- Satoshi Nakamoto -- creator of the network Thomas helped popularize
- Bitcoin Core -- the protocol Thomas built educational and developer tools around
- Hal Finney -- fellow early Bitcoin contributor
- Laszlo Hanyecz -- another early Bitcoin figure known for a memorable transaction story
- Digital Gold -- Nathaniel Popper's history of early Bitcoin, covering this era