Patents touching Bitcoin and blockchain

Researched 2026-10-09. The note covers Bitcoin's building-block patents, the patent suits over Bitcoin technology, the large corporate portfolios (nChain/Craig Wright, Coinbase, Ledger, Bank of America, IBM and now Circle, Visa, Mastercard, Square/Block), and how the industry defends itself (COPA and other pledges).

How this was checked. Patent facts (number, title, inventors, assignee, dates, status, expiry, claim 1, litigation flags) come from each patent's Google Patents page, read on 2026-10-09. Full PDFs of 39 US patents and applications, plus two court documents and an NSA licensing statement, are saved in sources/patents/ (see sources/patents/INDEX.md). News and company pages are summarised in my own words with a link. Anything I could not confirm from a primary record is marked (unverified).

A caution on "status". Google Patents says its legal status, current assignee and priority dates "are an assumption and not a legal conclusion". "Active" means Google thinks the patent is in force; it does not mean the patent is valid or that anyone infringes it. A US patent normally runs 20 years from filing (longer with term adjustment). An "abandoned" application never became a patent and can be used by anyone.

The short version

1. Bitcoin itself is not patented. I found no patent or application filed by "Satoshi Nakamoto" (a search for an absence, so unverified). The building blocks Bitcoin uses (Merkle trees, chained time-stamps, SHA-256, elliptic-curve and Schnorr signatures) were patented decades ago, and all of those patents have now expired (§1).
2. The most important live patent fight is about Bitcoin's cryptography itself. Since May 2025, Malikie Innovations, which bought BlackBerry's old patents including Certicom's elliptic-curve ones, has been suing large Bitcoin miners (Core Scientific, MARA). Malikie says running Bitcoin's ECDSA/secp256k1 signature code infringes those patents (§3.1). Most of the patents have since expired, but damages for past years can still be claimed (6-year look-back under 35 U.S.C. § 286).
3. Most other Bitcoin patent suits are about mining infrastructure: immersion cooling, flare-gas generators, grid-power contracts and container layouts. They are not about the protocol (§3.2).
4. The largest portfolios: - nChain: Craig Wright is a named inventor on its earliest filings. It claims "over 3,900 patents and applications, over 1,090 granted" (CoinGeek, 2024); an outside analysis counted about 695 (GreyB, Sept 2024). - Circle: on 2026-07-27 it bought IBM's blockchain portfolio, nearly 1,000 issued patents, and made no defensive pledge. - Bank of America and IBM: both have long been among the top filers (§4).
5. Defences: the Crypto Open Patent Alliance (COPA, founded by Square in 2020), Blockstream's 2016 defensive patent pledge, and Unified Patents' "Blockchain Zone" (2024), which in July 2025 asked the USPTO to re-examine an nChain patent with Wright as inventor (§5).

1. The building blocks: patents behind Bitcoin's parts (all expired)

The Bitcoin white paper (2008) cites Stuart Haber and W. Scott Stornetta three times (refs [3], [4], [5]) and Ralph Merkle once (ref [7]) for the time-stamp chain and the Merkle tree. This is checked against the copy in sources/satoshi/Bitcoin-whitepaper-Nakamoto-2008-bitcoin.org.pdf. Those same people held US patents on the ideas.

The elliptic-curve patents of Certicom (later BlackBerry, now Malikie) belong to this list too. They are covered in §3.1, because they are being asserted now.

2. Fringe and contested patent stories about Satoshi

These claims are widely repeated. They are recorded here with labels rather than dropped.

• "The King–Oksman–Bry patent shows who Satoshi was" (fringe). US patent application US 2010/0042841 A1, "Updating and Distributing Encryption Keys", was filed on 2008-08-15 by Neal King, Vladimir Oksman and Charles Bry and later assigned to Infineon and Lantiq.
• In 2011 the journalist Adam Penenberg (Fast Company) noted three things. The bitcoin.org domain was registered three days after the filing. The application uses the phrase "computationally impractical to reverse". It describes related networking and encryption ideas. (Wikipedia: Satoshi Nakamoto)
• The phrase is in the application: it reads "computationally impractical to reverse-map" (checked in the saved PDF).
• All three men denied being Satoshi (same source).
• The application is about refreshing encryption keys in home networks. It says nothing about money, mining or a ledger. Google Patents lists it as abandoned.
• Treat this as coincidence-based speculation.
• "SHA-256 is an NSA patent, so Bitcoin has an NSA back door" (fringe). The patent is the NSA's (see §1). But the algorithm is a public standard, the NSA released the patent royalty-free in 2007, and I found no evidence of a back door in SHA-256. A patent discloses how something works; it does not hide anything.
• "Satoshi chose secp256k1 and ECDSA to stay clear of patents and NSA-chosen curves" (contested, unverified). This is often said, but I found no statement by Satoshi. It is ironic given §3.1: Malikie now argues that Bitcoin's ECDSA use infringes Certicom patents.
• Craig Wright's claim to be Satoshi (rejected by a court). Wright is the named inventor on many nChain patents (§4.1).
• The UK High Court ruled in COPA v Wright that he is not Satoshi. Mellor J ruled in March 2024 and gave the written judgment, [2024] EWHC 1198 (Ch), on 20 May 2024. The court found that documents Wright relied on were forged (copy in sources/satoshi/COPA-v-Wright-2024-EWHC-1198-Ch-judgment.pdf; summary in Wikipedia).
• That case was about identity and copyright, not about the validity of nChain's patents. Those patents stand or fall on their own (as noted by BSV Times, 2026-09-07).
• For the identity question, see notes/2026-10-09-who-is-satoshi.md.

3. Patent litigation over Bitcoin technology

3.1 Malikie Innovations v. Bitcoin miners: elliptic-curve cryptography (active)

• Who: Malikie Innovations Ltd. and Key Patent Innovations Ltd. Malikie acquired about 32,000 BlackBerry patents in 2023 (Cointelegraph, 2025-06-03). Google Patents shows the patents below moving from Certicom to BlackBerry (2019) and then to Malikie (June 2023).
• Malikie v. Core Scientific: filed 2025-05-12 in the Eastern District of Texas, No. 2:25-cv-00519-JRG-RSP. The report says Core refused licensing talks, arguing the demand letters violated its bankruptcy orders (Bloomberg Law, 2025-05-13).
• Core asked to move the case to the Western District of Texas.
• Malikie amended its complaint to accuse Core's high-performance-computing (HPC) work as well as its mining, and Core brought in CoreWeave for indemnity.
• On 2026-06-29 the Federal Circuit refused to order a transfer (In re Core Scientific, No. 2026-140, nonprecedential). The case stays before Judge Gilstrap in the Eastern District of Texas.
• The order is saved: sources/patents/2026-06-29-CAFC-26-140-In-re-Core-Scientific-Malikie-mandamus-denied.pdf.
• Malikie v. MARA Holdings (formerly Marathon Digital): filed in the Western District of Texas. An amended complaint was reported on 2025-07-24 (Block Tribune).
• It accuses MARA's ASICs, nodes and wallets of using ECDSA on the secp256k1 curve.
• It alleges wilful infringement after MARA ignored licensing notices sent in March and April 2025.
• Case number not found (unverified).
• Patents named in the MARA complaint (per Block Tribune). I checked each on Google Patents:

• Why it matters:
• This is the first wave of suits claiming that running standard Bitcoin software infringes, rather than some company-specific feature.
• Every one of the listed patents was expired by 2026-10-09, so Malikie cannot get an order stopping anyone. But US law allows damages for infringement during the six years before suit (35 U.S.C. § 286), which reaches back to about 2019.
• The attorney Aaron Brogan warned that, if the strategy were pursued widely, it "might undermine the security of the Bitcoin network". Michael Bacina said patent holders usually aim for settlements rather than court tests (both quoted by Cointelegraph).
• Open questions (unverified): whether ordinary node operators or wallet users are at risk; prior-art defences (Bitcoin's public-key recovery and secp256k1 code trace back to the open-source libsecp256k1 project).

3.2 Mining-infrastructure suits (cooling, power, gas, containers)

Why it matters: these suits show where the money is in Bitcoin patents: mining hardware, cooling and power deals, not the protocol. Several turned on validity challenges at the PTAB or on who the true inventor was, rather than on infringement.

3.3 Mining chips: AsicBoost and Bitmain

• AsicBoost is a shortcut in SHA-256 mining. Several "mid-states" share one message expansion, which saves about 20% of the work (Hanke, arXiv 1604.00575, 2016).
• Timo Hanke and Sergio Demian Lerner filed it as WO 2015/077378 (priority 2013-11-19, applicant Sunrise Tech Group).
• The US member is US 11,113,676 B2. It was granted 2021-09-07, is active until 2036-04-16, and has been assigned to "Circle Line International Ltd". That is an unrelated name; do not confuse it with Circle Internet Group (relationship unverified).
• The family includes EP 3 095 044 B1 and CN 106415530 A. Google flags litigation in the family, details not found (unverified).
• Bitmain's Chinese filing CN 105245327 A was filed 2015-08-21. Its inventors include Jihan Wu (吴忌寒) and Micree Zhan (詹克团). It optimises a Bitcoin proof-of-work chip by holding one input fixed and varying another, an AsicBoost-style idea. Google lists it as "pending" (stale or unverified).
• The 2017 "covert AsicBoost" dispute (contested):
• On 2017-04-05 Gregory Maxwell said some mining hardware secretly used AsicBoost in a form that clashes with SegWit, implying Bitmain.
• Bitmain replied that it "holds the AsicBoost patent in China", that its chips support it, and that it had not used it on mainnet (Bitcoin Magazine).
• The original mailing-list post was blocked to me (gaps).
• The open, "overt" form was later standardised as version-rolling in BIP 320.
• Intel also filed (and abandoned) a "version rolling" mining-engine application, US 2022/0058167 A1.
• Bitmain v. MicroBT (China):
• Bitmain's 2017 patent suit against MicroBT was dismissed in 2018, and the Bitmain patent was revoked.
• In 2021 Bitmain filed a trade-secret suit in the Beijing IP Court for 99 million yuan (about $15 million) against MicroBT and its founder Yang Zuoxing, Bitmain's former chip designer (The Block, 2021-04-07).
• Outcome not found (unverified).
• Newer mining-chip patents:
• Bitmain US 12,621,175 B2 (granted 2026-05-05): N compressors share one input while each works through its own group of inputs.
• Intel US 10,313,108 B2 (granted 2019-06-04): energy-efficient double-SHA-256 mining accelerators.
• Block WO 2024/010804 A1 (filed 2023-07-05): precomputing parts of SHA-256 message expansion as constants for an energy-efficient mining chip.
• Coinbase US 12,063,291 B2 (granted 2024-08-13): SHA-256 circuitry with 64 rounds that store only the A and E registers. It was first assigned to 21, Inc. and moved to Coinbase on 2022-11-15.

3.4 Exchanges

• Anuwave v. Coinbase (D. Del., June 2019) asserted US 8,295,862, "Method and system to enable communication through SMS communication channel". It targeted Coinbase's text-message commands (Decrypt).
• Anuwave is described as an affiliate of the patent-assertion firm IP Edge.
• Google shows the same patent asserted in many courts, and it has now expired (fee related).
• Outcome not found (unverified).
• This is the typical "patent troll" pattern: a generic, older patent aimed at a crypto company's ordinary feature.

3.5 nChain and Craig Wright

• No nChain patent-infringement lawsuit found (unverified). I found none in news, the court records reachable to me, or Google's litigation flags on the nChain patents checked. Bitcoin SV community threads speculate about enforcement (r/bitcoincashSV). Wright's well-known suits were about copyright, database rights and identity, not patents (see notes/2026-10-09-who-is-satoshi.md).
• The challenge going the other way: on 2025-07-10 Unified Patents filed an ex parte re-examination request against nChain's US 12,032,677 B2 (Unified Patents).
• The patent is "Agent-based Turing complete transactions integrating feedback within a blockchain system", by Craig Steven Wright and Stephane Savanah.
• Plain words of claim 1: running a loop on a computer and letting the blockchain's state steer it, where the process is automated voting or hands out tokens tied to cryptocurrency.
• The outcome of the re-examination was not found (unverified).

4. Company portfolios

4.1 nChain / Craig Wright

• Size (contested):
• CoinGeek reported that nChain held "over 3,900 patents and applications" with "over 1,090 … granted", and ran a licensing programme of over 480 licences. In GlobalData's Q4 2023 table nChain led blockchain filings (77 that quarter, versus Bank of America 39, IBM 34, Tencent 32) (CoinGeek, 2024-02-01, updated 2025-03-17).
• CoinGeek is part of the same Calvin Ayre-linked business group as nChain (affiliation from common knowledge, unverified here), so treat its counts as the company's own claims.
• GreyB counted about 695 nChain patents as of September 2024. Most were filed in the UK, then the US, China and Japan (GreyB).
• The gap is probably applications versus grants and family versus member counting (unverified).
• Who owns it now: recent US grants (2025–26) list nChain Licensing AG (Zug, Switzerland) as assignee.
• BSV Times reports two more Wright-inventor US patents granted 2026-08-25 to nChain Licensing AG (numbers not found, unverified).
• On 2025-01-01 Teranode Limited bought nChain UK's trade and assets. It was renamed Neobridge Solutions Limited on 2026-09-04, and its 2024 accounts name C. Ayre as ultimate controller.
• Whether the patent portfolio moved with that sale is not shown in public records (BSV Times, 2026-09-07).
• Licensing: the BSV node software is released under the Open BSV License (version 5 in the GitHub repo; BSV Times reports version 6 for Teranode). Its key condition is that the software "must only be used on the BSV Blockchains". If you break that, "you can be enjoined from violating BSV's intellectual property rights" (bitcoin-sv LICENSE). Whether nChain's patents are licensed royalty-free only for BSV is often said but unverified; I found no patent-licence text.
• Representative patents (all checked; PDFs saved for the US ones):

4.2 Coinbase (COPA platinum member)

• The March 2014 batch: about nine Coinbase applications with a 2014-03-17 priority date (filed 2015-03-17, published 2015-09-17), naming Brian Armstrong, Fred Ehrsam and others. Several became patents; their claims were narrowed during examination.
• US 10,755,241, "Hot wallet for holding bitcoin" (granted 2020-08-25). Store a vault address's private key, split it into overlapping codes, send each code to separate remote storage, delete the key locally, and move hot-wallet value into the vault.
• US 10,510,053, "Send cryptographic currency to email address" (granted 2019-12-17).
• US 10,229,396, "Bitcoin exchange" (granted 2019-03-12): a matching engine and clearing for buy and sell offers.
• US 10,614,430, "Instant exchange" (granted 2020-04-07).
• US 10,891,600, "User private key control" (granted 2021-01-12).
• US 9,436,935, "Tip button" (granted 2016-09-06).
• Abandoned: "Bitcoin private key splitting for cold storage" (US 2015/0262171), "Personal vault" and "Off-block chain transactions in combination with on-block chain transactions".
• Later security patents:
• US 9,735,958, "Key ceremony …" (filed 2015-05-19, granted 2017-08-15). A master key is split into N shares held by custodians, with separate TLS keys, so no single person can unlock the signing system.
• US 10,903,991, "Systems and methods for generating signatures" (granted 2021-01-26). Multi-party computation (MPC) signing, in which key shares sign without ever reassembling the key.
• US 11,394,543 (granted 2022-07-19): encrypted backup of wallet secrets, with the key held by a separate recovery agent.
• Why it matters: the 2014 filings were an early sign that exchanges would patent custody methods. Coinbase is now a COPA platinum member (COPA members). Its pledge covers patents COPA calls "foundational" to crypto (COPA FAQ). Which specific Coinbase patents count as "foundational" is unverified.

4.3 Ledger (gap)

• I could not list Ledger SAS's patents. The search tool found none, Justia and PlainPatent were behind Cloudflare challenges, and the USPTO search API rejected my unauthenticated request (see gaps).
• Ledger is not on COPA's member list, checked 2026-10-09. Other hardware-wallet makers are: SatoshiLabs (Trezor), Coinkite and Foundation Devices (COPA members).
• No patent suit by or against Ledger was found (unverified).

4.4 Bank of America

• BofA is among the most active blockchain filers: 39 blockchain applications in Q4 2023 per GlobalData, as cited by CoinGeek. It publishes a patent list at bankofamerica.com/company/patents.
• The 2014 cryptocurrency batch, by inventors including Thomas Durbin and James Ronca:
• US 2015/0262173 A1, "System and Method for Wire Transfers Using Cryptocurrency" (filed 2014-03-17; abandoned). Route a customer's wire through buying bitcoin on one exchange and selling it on another when that is "optimal".
• US 10,255,600, "Cryptocurrency offline vault storage system" (filed 2014-06-16, granted 2019-04-09). Customer deposits go into a networked vault that is disconnected from the network once holdings exceed a threshold.
• US 10,275,772, "Cryptocurrency risk detection system" (granted 2019-04-30). Score the risk of a transaction from blockchain data, for example the age of the coins.
• US 10,127,552, "Cryptocurrency aggregation system" (granted 2018-11-13).
• Three sibling applications (transaction payment, transaction validation, suspicious-user alert) were abandoned.
• Later: US 11,188,897, "Multi-tiered digital wallet security" (2021), and US 11,790,363, "Cryptocurrency storage distribution" (2023).
• Why it matters:
• A large US bank has held granted patents on custody ("offline vault") and on screening coins by history since 2018–19.
• BofA is not a COPA member.
• A hot wallet is a network-connected key store; cold or offline storage is key storage kept off the network. The vault patent is a bank's version of that standard defence against hot-wallet theft.

4.5 IBM → Circle (July 2026)

• IBM filed widely on enterprise blockchains (Hyperledger-style). Two examples:
• US 10,367,645, "Proof-of-work for smart contracts on a blockchain" (granted 2019-07-30).
• US 11,568,416, "Cryptocurrency transaction pattern based threat intelligence" (granted 2023-01-31). It pulls crypto addresses out of phishing emails and graphs their transactions to track criminal campaigns.
• 2026-07-27: Circle bought IBM's blockchain portfolio: "over 680 patent families and nearly 1,000 issued patents worldwide", covering ledger technology, finance, insurance, supply chain and cloud. The price was not disclosed (Circle press release).
• Circle did not join COPA or make a defensive pledge. It is a member of the LOT Network, which guards only against patents being sold to trolls (Tech Times, 2026-07-28).
• Fortune's Jeff John Roberts argued the patents could be used for litigation or royalty campaigns (Fortune, 2026-08-03). This is opinion, not a reported action.
• On 2026-10-09 Google Patents still listed IBM as current assignee of the two IBM patents above. Either the assignments are not yet recorded or those two were not in the deal (unverified).
• Why it matters: in one deal the largest US blockchain patent holder became a company with no non-assertion pledge.

4.6 Visa

• US 11,507,929, "Digital fiat currency" (application US 2020/0151682, filed 2019-11-08, granted 2022-11-22, active to ~2040).
• Granted claim 1, plainly: a central bank's computer, holding a certificate from the payment network, turns a banknote's serial number and denomination into a digital token recorded on a blockchain, then has the paper note taken out of circulation.
• Why it matters: it is a payments-network design for central-bank digital currency (CBDC) and tokenised cash.
• US 11,055,707, "Cryptocurrency infrastructure system" (filed 2015-06-24, granted 2021-07-06). A permissioned crypto network in which "issuer" nodes may create currency and "distributor" nodes may only pass it on, with keys issued by a management server.
• Visa holds many more crypto filings (for example "Federated custodian" and "Rapid cryptocurrency transaction processing"), as seen in Google's related-document lists. They were not reviewed one by one.

4.7 Mastercard

• US 9,948,467, "Method and system for blockchain variant using digital signatures" (filed 2015-12-21, granted 2018-04-17). A permissioned blockchain in which a domain key signs each member's key and blocks are checked against those signatures.
• US 10,963,881, "Method and system for fraud control of blockchain-based transactions" (filed 2015-05-21, granted 2021-03-30). Card-network messages carry a blockchain network identifier so that blockchain payments can be tied to verified card accounts.
• Why they matter: they show the card networks patenting the bridge between identity-checked card rails and blockchains. Neither Mastercard nor Visa is a COPA member.

4.8 Square / Block (COPA founder)

• US 10,540,639, "Cryptocurrency payment network" (priority 2017-07-26, granted 2020-01-21; continuations US 11,710,108, 2023, and US 12,106,271, 2024). A payment request in dollars is paid from the payer's crypto balance, and the service swaps through its own balances so the payee receives dollars: a Cash App-style flow.
• WO 2024/010804: Block's mining-chip hashing application (see §3.3).
• COPA: Square launched COPA on 2020-09-10 and said it would contribute its own crypto patents. Its stated reason was that "locking up foundational cryptocurrency technologies in patents stifles innovation" (CoinDesk). Block is a platinum member (COPA members).

4.9 Others worth knowing

• Blockstream:
• US 10,812,274, "Transferring ledger assets between blockchains via pegged sidechains" (granted 2020-10-20). Inventors are Adam Back, Gregory Maxwell, Matt Corallo, Luke Dashjr, Mark Friedenbach and Andrew Poelstra.
• "Cryptographically concealing amounts …" (Confidential Transactions), granted as US 11,062,303 on 2021-07-13.
• Both are covered by Blockstream's defensive pledge (§5).
• It is notable that well-known Bitcoin Core contributors are named inventors on these patents.
• BitGo: US 2015/0120569, "Virtual currency address security" (2014; abandoned). Its claim was to build an address from several parties' public keys: 2-of-3 multisig custody. A later BitGo grant with a similar title is US 11,120,438 B1, "Cryptocurrency address security" (2021); its family link to the 2014 application was not checked.
• Accenture: US 9,967,088, "Rewritable blockchain" (granted 2018-05-08). A trusted key-holder can rewrite a past block using a "chameleon" hash. It is the opposite of Bitcoin's immutability, and it is often cited in debates about editing ledgers for GDPR-style erasure.
• PayPal, Fidelity (FIS), Intel, Alibaba/Ant and Tencent also hold many blockchain filings (seen in Google's related-document lists). They were not reviewed in depth here.

5. Defences: how Bitcoin projects protect themselves from patents

1. Expiry and prior art. Bitcoin's core building blocks were patented in 1979–2001, and those patents have all expired (§1). Open publications such as the white paper, BIPs, mailing-list posts and code commits are prior art, which can defeat later patents claiming the same idea.
2. Crypto Open Patent Alliance (COPA), founded 2020-09-10: - Members promise not to use crypto-foundational patents offensively, except to defend themselves or the community, or against impersonators. The pledge is described as "legally binding and enforceable". - Members can draw on a shared patent library for defence. Joining does not require contributing patents. Membership is free for individuals and priced by revenue for companies (COPA FAQ). - Platinum members are Aquarius, Block, BtcTurk, Coinbase and Microstrategy. General members include Blockstream, Kraken, Chaincode Labs, Mempool, BitPay, SatoshiLabs, Coinkite, Foundation Devices, Uniswap, Worldcoin and others (members page, 2026-10-09). - Meta was reported to have joined in 2022, but the article link returned 404 (unverified), and Meta is not on the current list. - COPA was also the claimant that defeated Wright's Satoshi claim (§2).
3. COPA × Unified Patents "Blockchain Zone" (2024-10-01). COPA members get free cover from Unified Patents, which challenges patents of non-practising entities ("patent trolls") at the USPTO instead of paying settlements (COPA announcement). Its first public crypto target was the nChain patent above (§3.5).
4. Blockstream's defensive patent pledge (2016-07-19; v1.1 2017-04-24): - Blockstream will assert its software patents only defensively and offers them under the Defensive Patent License 1.1. It says the pledge binds future owners of the patents (pledge; EFF, 2016). - Contested: critics argued a company pledge is still "trust us" (IP Watch, 2016-07-21; r/btc thread).
5. USPTO challenges: - Inter partes review, post-grant review and ex parte re-examination are the tools used in the mining cases above (Crusoe vs Upstream, IPRs on Lancium, Midas and Certicom patents) and by Unified Patents vs nChain. - Outcomes are mixed. Upstream's claims survived on Director Review. Lancium's IPR was not instituted. Midas's IPR is pending.
6. LOT Network (Circle is a member) only stops a member's patents from being sold to trolls. It does not limit the member's own suits (Tech Times, above).
7. The counter-model: field-restricted licences. The Open BSV License lets BSV software be used only on BSV and threatens injunctions otherwise (§4.1). It is the opposite approach to COPA.

Link to hacks (the wider research question). Several custody patents describe the standard defences against theft of exchange keys:

• splitting keys into shares (Coinbase US 10,755,241, nChain US 10,659,223);
• multi-custodian key ceremonies (Coinbase US 9,735,958);
• MPC signing (Coinbase US 10,903,991);
• disconnected "offline vaults" (Bank of America US 10,255,600).

The 2014 Coinbase and BofA filings came weeks to months after Mt. Gox failed in February 2014 (date from general knowledge, not re-checked here). That is timing only: the filings do not mention Mt. Gox (any causal link unverified). For the hacks themselves, see sources/hacks/. Patents on these methods could, in principle, be asserted against wallets that use the same techniques. For the companies checked here, COPA membership (Coinbase, Block) or the DPL (Blockstream) makes that unlikely. BofA, Circle (ex-IBM), Visa, Mastercard and nChain have no such pledge.

6. Gaps and open questions

• Ledger's patents: not listed (sites blocked). Check https://patents.google.com/?assignee=Ledger+SAS&oq=assignee:(Ledger+SAS) in a browser.
• nChain: an exact count of grants versus applications, how many name Wright, and whether the portfolio passed to Teranode/Neobridge.
• Malikie: the MARA case number and the full patent list (the US 8,522,286 discrepancy).
• Outcomes not found: the US 12,032,677 re-examination; Digital Shovel; Anuwave v. Coinbase; BearBox's Federal Circuit appeal (2025, unverified).
• Mastercard: its widely reported "linkage of blockchain-based assets to fiat accounts" patent was not identified by number.

Spark run on this topic (pointer added by the completeness check, 2026-10-09)

The local Spark run 20261009-143847--what-patents-have-been-granted-or-filed-on-bitcoin-and-block finished on 2026-10-09. Its findings are not merged into this note yet. Its CONTESTED and UNDOCUMENTED answers, the claims its verifier rejected or found only partly supported, the facts it dropped, and the pages it refused or skipped are all listed and flagged in RESEARCH-STATUS-2026-10-09.md § 6, as the editor asked (include everything the Spark rejects, labelled). Its "no patents found" answers for nChain, Coinbase and Bank of America are wrong. The patents saved in sources/patents/ show grants for all three (§ 6.1).