Google engineer who became an early Bitcoin contributor and corresponded with Satoshi
On April 12, 2009, a Google engineer named Mike Hearn read the Bitcoin whitepaper and emailed Satoshi Nakamoto. Over the next two years they exchanged sustained technical correspondence — scaling, simplified payment verification, the long-run shape of mining. Hearn received one of the last private emails Satoshi ever sent:
“I’ve moved on to other things. It’s in good hands with Gavin and everyone.”
Almost five years later, on January 14, 2016, Hearn published “The resolution of the Bitcoin experiment” on Medium. It opened with three words:
“Bitcoin has failed.”
He sold all his bitcoins, left the project, and joined R3, an enterprise-blockchain consortium where he co-led development of the Corda distributed ledger. In August 2017 he made his Satoshi correspondence public — one of the largest documented bodies of Satoshi’s technical thinking. In February 2024 he testified in the COPA v Wright trial.
Hearn worked at Google on Maps, Earth, and Gmail’s anti-spam systems. He developed BitcoinJ, a Java implementation of the protocol — the first major alternative to the original C++ client and the basis for many Android Bitcoin wallets.
Between April 2009 and April 2011, Hearn and Satoshi exchanged sustained technical email. Topics included how the system could scale, how simplified payment verification (SPV) clients would work, and how Satoshi envisioned the evolution of mining from CPUs to specialized hardware. Hearn was among the very first people outside the initial cypherpunk circle to take a serious technical interest in Bitcoin, and the published archive of his correspondence with Satoshi documents the technical thinking Satoshi never spelled out in public posts.
The January 2016 “Bitcoin has failed” essay cited two principal grievances: the inability of the development community to reach consensus on raising the 1-megabyte block size limit, and what Hearn described as systemically important institutions emerging within what was supposed to be a decentralised system. He sold his coins concurrent with publication.
20 entries
Genealogy of every Bitcoin protocol fork that left a separate chain alive (Bitcoin Cash, SV, Gold) and the adjacent cryptocurrencies derived from Bitcoin (Namecoin, Litecoin, Dogecoin).
Mike Hearn contacts Satoshi Nakamoto for the first time with questions about Bitcoin's scalability, mining hardware, inflation schedule, and coin denominations.
Mike Hearn asks Satoshi whether the Electronic Funds Transfer Act could apply to Bitcoin and if the inability to do chargebacks risks making it illegal.
When correspondents wished Satoshi merry Christmas, predicted Bitcoin at $10M per coin, or hoped he was doing well, his replies opened on the technical topic and never returned. Five-pattern audit.
Mike Hearn asks about the origin of the 21 million coin limit, the 10-minute block target, and the 500KB block size limit while working on a Java SPV implementation for Android.
Mike Hearn announces the open-source release of BitcoinJ under the Apache 2 license, and asks about merkle branch verification, scripting language ideas, and why transaction replacement was disabled.
Mike Hearn describes his work on Google's abuse team and proposes using Bitcoin as collateral against accounts for spam prevention, asking about time-locking coins.
Mike Hearn's private email correspondence with Satoshi Nakamoto, in which Satoshi stated he had 'moved on to other things' and that Bitcoin was 'in good hands with Gavin and everyone.'
Satoshi's final known private messages: April 23, 2011 to Mike Hearn — "in good hands with Gavin." April 26 to Andresen, transferring the alert key and saying he would probably be unavailable.
The hypothesis that Len Sassaman (cypherpunk cryptographer, died July 3, 2011) was Satoshi. Frame: timing argument and cypherpunk credentials. Counter: no direct documentary link, no widow comment.
Editorial reading of how the 2014 'Bitcoin Core' rebrand reshaped Bitcoin's authority vocabulary — PR #3408 internal disagreement, the 2015-2017 fork episodes, and Hearn's 2025 retrospective regret.
Weighing the 'Blockstream controls Bitcoin' charge against the record: where it comes from, the facts behind it, and the counter-facts — Lightning's authorship, funding spread, a shrinking Core role.
Cross-cutting reading of Bitcoin's 2015–2017 block-size war by phase, faction, and turning point: Bitcoin XT, BIP148 UASF, the New York Agreement, Bitcoin Cash, SegWit2x cancellation.
Why Bitcoin's 2015-2017 fork wars ran as identity contests, not OSS disputes: the post-2011 authority vacuum, the economic weight on rule choices, and the three layers that bound code to currency.
Mike Hearn and Gavin Andresen released Bitcoin XT 0.11A, a Bitcoin Core fork implementing BIP 101 — 8 MB blocks doubling every two years. The launch opened the public phase of the block-size war.
Mike Hearn published The Resolution of the Bitcoin Experiment, declaring Bitcoin had failed due to governance breakdown and the block-size stalemate. He sold all his coins and left the project.
Mike Hearn publishes his private email correspondence with Satoshi Nakamoto, providing valuable insights into Satoshi's thinking about Bitcoin's technical future.
Jameson Lopp argues Hal Finney could not have been Satoshi: on April 18, 2009, Finney was running a 10-mile race in Santa Barbara during a window of Satoshi network activity.
Mike Hearn testifies at the COPA v Wright trial, recounting his direct interactions with Satoshi and describing how Wright failed his technical check questions at a 2016 dinner.
In a CoinGeek interview, Mike Hearn offers rare reflections on Satoshi's personality — observing he enjoyed experimenting but appeared to grow frustrated when evangelical personalities arrived.