David Chaum founds DigiCash in April 1990 to commercialize cryptographic electronic cash based on blind signatures. Banks including Deutsche Bank later licensed the eCash system; DigiCash filed for bankruptcy in 1998.
Eric Hughes publishes A Cypherpunk's Manifesto, arguing that privacy in an open society requires cryptography and software that individuals write and run themselves. The cypherpunks' mailing list becomes a seedbed for later digital-cash designs.
Adam Back proposes Hashcash, a proof-of-work system originally aimed at email spam and denial-of-service. Bitcoin later cites Hashcash as the proof-of-work function used to mint new coins and secure the chain.
Wei Dai describes b-money, a proposal for anonymous, distributed electronic cash secured by computational work and a public ledger of accounts. Satoshi cites b-money in the Bitcoin white paper.
Hal Finney releases Reusable Proofs of Work (RPOW), a system that makes Hashcash tokens transferable by reissuing them from a trusted server after each spend. Finney later becomes one of Bitcoin's first users.
Nick Szabo posts a detailed description of bit gold: unforgeable costly bits created by proof-of-work, chained and timestamped. The design is often cited among Bitcoin's conceptual precursors.
The bitcoin.org domain is registered on August 18, 2008. Bitcoin.org later states that the domain was originally registered and owned by Satoshi Nakamoto and Martti Malmi.
Satoshi Nakamoto posts "Bitcoin P2P e-cash paper" to the Cryptography Mailing List, linking a nine-page PDF that describes a peer-to-peer electronic cash system without trusted third parties.
Block 0 is mined with timestamp 18:15:05 UTC. Its coinbase contains the Times headline "Chancellor on brink of second bailout for banks." The 50 BTC subsidy in the genesis block is unspendable by design.
Satoshi sends 10 BTC to Hal Finney as a test. The transfer is confirmed in block 170. Finney later wrote that he was the first person besides Satoshi to run the software.
Laszlo Hanyecz reports on BitcoinTalk that he traded 10,000 BTC for two pizzas, after posting the offer on May 18, 2010. The thread becomes a lasting marker of early bitcoin-as-payment experiments.
dwdollar announces Bitcoin Market on BitcoinTalk, an early web exchange that lets users trade bitcoin for dollars via PayPal. It is among the first dedicated bitcoin/fiat marketplaces.
A transaction in block 74,638 creates about 184 billion BTC by exploiting a signed-integer overflow in output-value checks. Within hours the chain is forked to a fixed client; the bad chain is abandoned. The incident is one of Bitcoin's earliest consensus-critical bugs.
Forum user ArtForz describes mining with ATI GPUs on BitcoinTalk, noting large speedups over CPU mining. GPU mining soon dominates until FPGAs and ASICs arrive.
Federal prosecutors later stated that the Silk Road marketplace operated from January 2011 to October 2013, using bitcoin as its primary means of payment for illicit goods.
In June 2011 Mt. Gox suffers a major compromise in which the exchange rate is manipulated and accounts are breached. The incident damages confidence in early custodial exchanges.
Developers and miners choose between BIP 16 (P2SH) and BIP 17 (OP_EVAL alternative). BIP 16 wins miner support and later activates, an early example of soft-fork governance by running code.
Pay-to-Script-Hash soft-fork activates, letting complex scripts (including early multisig) be paid to a script hash instead of revealing the full script up front. BIP 16 defines the rules.
BIP 32 specifies HD wallets: a master seed can derive many keys without storing each privately. The design becomes the basis for modern seed-phrase wallets (later BIP 39/44).
Bitcoin Core 0.8 and 0.7 nodes disagree on a block after a BDB locks limit change, splitting the chain. Operators are urged to temporarily run 0.7; the shorter chain is abandoned.
A blockchain fork occurs after different Bitcoin Core versions disagree on a block database limit (BDB locks). Operators are urged to downgrade; the shorter chain is abandoned. The incident hardens upgrade discipline.
FinCEN issues FIN-2013-G001. It treats administrators and exchangers of convertible virtual currency as money transmitters under the Bank Secrecy Act, while ordinary users spending virtual currency for goods or services are not MSBs solely for that use.
Homeland Security seizes Mt. Gox's U.S. Dwolla account funds, alleging the exchange operated as an unregistered money transmitter. The action foreshadows heavier U.S. AML enforcement.
Federal agents arrest Ulbricht in San Francisco and seize the Silk Road website. Prosecutors allege Ulbricht operated the marketplace under the name Dread Pirate Roberts.
Along with shutting Silk Road, federal agents seize large quantities of bitcoin associated with the marketplace and Ulbricht, later auctioned by the U.S. Marshals Service.
The Senate Homeland Security and Governmental Affairs Committee holds a hearing titled Beyond Silk Road, examining risks and promises of virtual currencies with FinCEN and other witnesses.
Senate committees hold hearings on bitcoin and virtual currencies. Regulators including FinCEN and the Federal Reserve discuss AML treatment and consumer risks without calling for an outright ban.
Mt. Gox stops bitcoin withdrawals, citing a "transaction malleability" bug. Two weeks later the company files for bankruptcy in Tokyo after disclosing massive missing bitcoin.
Mt. Gox Co., Ltd. files for bankruptcy protection in Tokyo after suspending withdrawals and reporting that hundreds of thousands of bitcoins belonging to customers and the company are missing. Customer claims proceed for years through Japanese court proceedings.
The IRS issues Notice 2014-21, stating that convertible virtual currency is treated as property for U.S. federal tax purposes. General property-transaction rules apply to gains, losses and payments.
A Manhattan federal jury finds Ulbricht guilty on seven counts, including narcotics trafficking conspiracy, money laundering conspiracy and computer hacking conspiracy, tied to Silk Road.
Judge Katherine Forrest sentences Ulbricht to life imprisonment plus forfeiture after the February 2015 conviction. Appeals follow; the life sentence stands until a 2025 pardon.
Superintendent Ben Lawsky announces the final BitLicense regulation text. The regulation is published and takes effect June 24, 2015 as 23 NYCRR Part 200.
BIP 66 requires strict DER encoding of ECDSA signatures, closing malleability vectors that complicated unconfirmed transaction chains and early Lightning designs.
New York's 23 NYCRR Part 200 virtual currency regulation (BitLicense) takes effect. Firms engaging in covered virtual-currency business activity involving New York must obtain a license from NYDFS.
Joseph Poon and Thaddeus Dryja publish a draft of The Bitcoin Lightning Network, describing hashed timelock contracts and off-chain payment channels that settle on Bitcoin.
Bitfinex reports a security breach involving a large loss of bitcoin from a multi-signature setup. Later U.S. criminal cases describe about 119,754 BTC stolen in August 2016.
After the August 2 hack, Bitfinex socializes the remaining shortfall by issuing BFX creditor tokens to customers, later redeemed as the exchange recovers.
Bitcoin Core publishers announce retirement of the network-wide alert system after key-compromise concerns. Later releases remove alert support entirely.
The SEC denies the Winklevoss Bitcoin Trust listing application, citing markets for bitcoin being "readily susceptible to manipulation." Spot ETP approvals arrive years later in 2024.
Digital Currency Group circulates the New York Agreement: miners and companies pledge to activate SegWit and later raise the base block size (SegWit2x). The compromise splits the community and ultimately fails on the hard-fork half.
BIP 174 specifies PSBT, an interchange format so wallets, hardware devices and multisig cosigners can collaboratively sign without exposing private keys.
BIP 91 reaches its signaling threshold, effectively committing miners to SegWit activation and defusing an immediate chain split over the New York Agreement timeline.
User Activated Soft Fork (BIP 148) nodes enforce SegWit signaling after August 1, 2017. Combined with BIP 91 miner signaling, SegWit locks in without a permanent chain split on the Bitcoin network.
A faction opposing SegWit and supporting larger on-chain blocks creates Bitcoin Cash at block 478,558, raising the block size limit on its chain. Bitcoin Core's chain continues without that rule change.
Segregated Witness (BIP 141) activates at block 481,824 after years of block-size debate. Witness data is discounted for block weight, enabling Lightning and fixing certain malleability issues.
Major SegWit2x supporters state that the planned November hard fork to raise the base block size lacks sufficient consensus and will not proceed, ending the New York Agreement's remaining on-chain size increase.
Multiple Lightning implementations (including lnd, c-lightning and eclair) reach usable mainnet beta stages, allowing real bitcoin channels after SegWit. Early capacity is small and software still experimental.
BOLT 4 specifies Sphinx-style onion routing for Lightning payments so intermediate nodes learn only the prior and next hop, a core privacy and routing property of the network.
Lightning payments use Sphinx-style onion routing so intermediate nodes learn only previous and next hops. BOLT specs document the cryptographic path construction.
Basis of Lightning Technology (BOLT) documents define interoperable Lightning protocol rules across implementations. Spec work continues as an open multi-implementation process.
MicroStrategy announces it has purchased 21,454 BTC for about $250 million as its primary treasury reserve asset, an early large public-company bitcoin treasury move.
PayPal announces U.S. users can buy, hold and sell bitcoin and other cryptocurrencies in its app, expanding retail access while keeping assets custodial inside PayPal.
Tesla's Form 10-K for 2020 discloses that the company invested $1.50 billion in bitcoin. Later filings and posts describe partial sales and policy changes on accepting bitcoin for cars.
China's State Council Financial Stability and Development Committee calls for a crackdown on bitcoin mining and trading. Provincial actions accelerate through May and June 2021, pushing a large share of global hashrate offline.
El Salvador's Legislative Assembly approves Decree No. 57 (Bitcoin Law) on June 8, 2021, published June 9. The law makes bitcoin legal tender with unrestricted liberating power; it takes effect 90 days after publication.
Through June 2021, publicly reported hashrate estimates fall sharply as Chinese mining exits. Subsequent months show recovery as machines relocate, preceding the July 3 record difficulty drop.
Difficulty adjusts down about 27.94% at block 689,472 as hash power leaves China—the largest downward adjustment recorded to that date. Mining capacity later reappears in North America and elsewhere.
Ninety days after Official Gazette publication, bitcoin becomes legal tender alongside the U.S. dollar. The government rolls out a Chivo wallet and ATM network; adoption and technical issues are widely reported.
Taproot (BIPs 340/341/342) activates at block 709,632, adding Schnorr signatures, Taproot outputs and Tapscript. Complex spends can look like single-key spends on-chain when conditions cooperate.
Federal prosecutors announce the arrest of Ilya Lichtenstein and Heather Morgan on charges related to laundering cryptocurrency allegedly stolen in the 2016 Bitfinex hack. Agents seize a wallet holding roughly 94,636 BTC.
President Biden signs Executive Order 14067 directing federal agencies to study digital-asset risks and opportunities, including consumer protection, financial stability and illicit finance.
President Biden signs EO 14067 directing agencies to report on digital-asset consumer protection, financial stability, illicit finance and U.S. competitiveness.
Celsius Network pauses customer withdrawals amid market stress, later filing bankruptcy. The failure is a major custodial-lender case study for self-custody advocates.
FTX Trading Ltd. and affiliates file for Chapter 11 bankruptcy after a run on deposits. Criminal cases against founder Sam Bankman-Fried follow; bitcoin markets sell off sharply.
Casey Rodarmor's Ordinals protocol numbers satoshis and enables inscriptions of arbitrary content in witness data. Inscription #0 is recorded; the practice later drives large fee spikes and policy debates over data-carrying transactions.
Inscription demand pushes median fees sharply higher for stretches of 2023. Mempool.space and similar explorers show congestion; debates over "spam" versus valid fee-paying use intensify.
The SEC files civil complaints against Binance entities (June 5) and Coinbase (June 6), alleging unregistered securities offerings and exchange registration violations. Litigation continues for years.
The SEC files a civil complaint against Binance entities and Zhao alleging unregistered exchange, broker-dealer and securities offerings. A related Coinbase suit follows the next day.
The U.S. Court of Appeals for the D.C. Circuit vacates the SEC's denial of Grayscale's proposal to convert its Bitcoin Trust into a spot bitcoin ETP, holding the SEC's reasoning arbitrary and capricious relative to futures-based products.
Binance pleads guilty to BSA violations; Changpeng Zhao steps down and later receives a prison sentence. The plea agreements are filed in federal court.
The day after SEC approval, spot bitcoin exchange-traded products begin trading on U.S. exchanges. Issuers publish prospectuses and holdings methodologies.
Casey Rodarmor's Runes fungible-token protocol launches around the fourth halving, contributing to elevated fees. Like Ordinals, it uses Bitcoin transaction data without changing consensus rules.
Casey Rodarmor's Runes fungible-token metaprotocol launches around block 840,000. Like Ordinals, it uses Bitcoin transaction data without changing consensus rules and coincides with elevated fees.
Prosecutors charge Samourai's co-founders with conspiracy to commit money laundering and to operate an unlicensed money transmitting business, alleging the mixer moved criminal proceeds. Privacy advocates such as Coin Center argue non-custodial software developers should not be treated as money transmitters.
Legislative Decree No. 199 (Jan 29, 2025), published Jan 30, reforms the Bitcoin Law so acceptance of bitcoin by private parties is voluntary rather than mandatory, among other changes. Bitcoin remains recognized under the revised framework.
Discussion and follow-up PRs (including #33453) reverse the deprecation of -datacarrier / -datacarriersize after user feedback, clarifying that operators may keep configuring the limit even after Core 30's default change.
Antoine Poinsot posts to the bitcoindev mailing list proposing to relax Bitcoin Core's OP_RETURN / datacarrier standardness limits. He argues the limits no longer bind data storage (witness data is cheaper) and push some protocols toward unspendable fake pubkeys that bloat the UTXO set.
Greg Sanders (instagibbs) opens Bitcoin Core pull request #32406 to raise the default -datacarriersize to 100,000 bytes and allow multiple OP_RETURN outputs per transaction for relay and mining, while retaining (and deprecating) the config options.
Coinbase files an SEC Form 8-K describing an incident in which overseas support contractors were bribed to copy customer account data. The company states that passwords, private keys and funds were not exposed.
Poinsot publishes a long Delving Bitcoin post answering community objections to relaxing OP_RETURN limits. Critics reply that filters raise the cost of spam, that Bitcoin should prioritize monetary use, and that UTXO-bloat arguments are inconsistent with not filtering inscriptions.
PR #32406 is merged. Default datacarrier policy will ship in the next major release: effectively uncapped OP_RETURN size for standardness purposes, with multiple data-carrier outputs allowed under an aggregate size budget.
Bitcoin Core 30.0 is published. Release notes state that -datacarriersize defaults to 100,000 (effectively uncapped given the max transaction size) and that multiple OP_RETURN outputs are permitted; operators can set -datacarriersize=83 to restore the prior limit. The change is policy, not consensus.
Keonne Rodriguez is sentenced to five years (Nov 6) and William Lonergan Hill to four years (Nov 19). The case remains a focal point in debates over privacy tools and developer liability.
Attackers begin sweeping wallets whose seeds were generated by flawed firmware on certain COLDCARD devices. Coinkite publishes advisories; see Security Status for dated firmware guidance.
On October 15, 2026, bitdis.org (sourcing btcnodes.io and mempool.space) reports Bitcoin Knots at 4,426 of 26,581 known nodes (16.65%), with Bitcoin Core at 22,093 (83.12%). Many Knots operators cite tighter default filters on data-carrying transactions; node-count methods differ across dashboards, so treat figures as estimates for that day's crawl.