Coinkite®: @OPENDIME, 1st & only #Bitcoin bearer instrument. @COLDCARDwallet ultra-secure open hardware wallet @theBLOCKCLOCK @TAPSIGNER est. block 141,000

Bitcoin
Joined May 2013
Coinkite’s standard data-retention practice is to blank customer records after 120 days, retaining only email and country. Customers can request earlier blanking after delivery. Our August notice explains the current legal-preservation exception: blog.coinkite.com/update-on-…
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I joked about CatCard being the “ColdCard x Mt Gox collab” but after spending weeks going down a self custody research rabbit hole I like this more and more especially as part of a multi-vendor/sig setup. @MagicalTux isn’t getting enough credit for this one, but it’s pretty impressive.
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Multi-vendor multi-sig users today having combined each of these gems into a 3-of-5
"the password you are attempting to use was part of a data breach are you sure you want to continue using it?" drone strike my house man i don't care anymore
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Coinkite retweeted
Authenticity systems have tradeoffs. Remote check is convenient, but concentrate trust & attacker incentives in one key. #COLDCARD chose distributed verification: local checks w/ a clear case, matched bag number, verified firmware & GENUINE|CAUTION LEDs blog.coinkite.com/understand…
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Coinkite retweeted
Keep your seed offline and safe from hacks. Dual secure elements protect every key.

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Authenticity systems have tradeoffs. Remote check is convenient, but concentrate trust & attacker incentives in one key. #COLDCARD chose distributed verification: local checks w/ a clear case, matched bag number, verified firmware & GENUINE|CAUTION LEDs blog.coinkite.com/understand…
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Coinkite retweeted
A clear case is not decoration. It lets you inspect a COLDCARD for a component swap or implant. The tamper-evident bag, anti-phishing words, dual Secure Elements and verified firmware add independent checks. That’s defense in depth. coldcard.com/docs/physical-n…
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Press 2 at the OK TO SEND? screen to open Transaction Explorer. Step through every input being spent and every destination or change output instead of approving from a summary alone. coldcard.com/docs/ready-to-s…
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Coinkite retweeted
Monday, Oct. 12, 2026 update: We remain locked out of @COLDCARDwallet and are still waiting for @X to restore our access.
We are investigating how a post containing a phishing link was published from this account. It has since been deleted. Do not visit or interact with that link. COLDCARD’s only official website is coldcard.com. This account has used offline 2FA with tightly restricted access since 2017. We have contacted @X and are reviewing all account access. We will share further verified updates here.
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Monday, Oct. 12, 2026 update: We remain locked out of @COLDCARDwallet and are still waiting for @X to restore our access.
We are investigating how a post containing a phishing link was published from this account. It has since been deleted. Do not visit or interact with that link. COLDCARD’s only official website is coldcard.com. This account has used offline 2FA with tightly restricted access since 2017. We have contacted @X and are reviewing all account access. We will share further verified updates here.
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Coinkite retweeted
I’m still running @COLDCARDwallet What else can people do? there is no peer. Update and roll your dice.
COLDCARD is a Bitcoin-only signing device. It does not require a COLDCARD account or mandatory companion app. Pair it with compatible wallet software and keep the signing key offline. coldcard.com/mk5
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Coinkite retweeted
COLDCARD now supports #Codex32 Shamir backups for existing BIP-39 and passphrase wallets. Choose your threshold. Same addresses. No coins moved. In 5.6.3 and 1.5.3Q. Save 10% when paying with Bitcoin. Learn more blog.coinkite.com/shamir-bac…
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Coinkite retweeted
I had a look at how many GitHub Stars different Hardware Wallet Projects have.
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COLDCARD is yours to verify, modify, and run. 👨‍💻 Learn how to change the open-source firmware, test it in the simulator, build a development-key DFU for Mk4/Mk5 or Q, and install it on a dedicated device. blog.coinkite.com/build-run-…
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Coinkite retweeted
🚨 New COLDCARD firmware is out: 5.6.2 for Mk4/Mk5 and 1.5.2Q for Q. View TRNG Words is back. We also added an offline tool to verify dice-roll or coin-flip mixing, USB ncry v3, and more transaction, Virtual Disk, firmware and wallet-state fixes. Please update promptly: coldcard.com/downloads Full notes: blog.coinkite.com/coldcard-f…
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Coinkite retweeted
How the new COLDCARD seed generation works (MK4/MK5 ≥5.6.1 and Q ≥1.5.1Q): Track the security status here: coldcard.com/security/status Explore the interactive tool and source code here: scgbckbone.github.io/seedflo…
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🚨 New COLDCARD firmware is available: 5.6.1 for Mk4/Mk5 and 1.5.1Q for Q. This release follows three weeks of sustained review since our July 31 hotfix. We continue to acknowledge the customers who suffered severe financial losses from the seed-generation attack. Every newly generated seed now requires one source of user entropy: at least 65 key presses with unpredictable timing, 50 physical dice rolls, or 128 physical coin flips. This input is combined with fresh entropy from the STM32 TRNG, SE1, and SE2. The release also adds staged-PSBT verification immediately before signing, stronger USB and firmware-update boundaries, improved Delta Mode isolation, active-wallet backup fixes, stronger RNG initialization and fault checks, safer SIGHASH defaults, and many additional security and correctness improvements. Important: Updating does not repair an existing seed generated on affected firmware. If the advisory applies to your seed, update your device, generate and verify a new seed, then move your funds. We strongly recommend that all Mk4, Mk5, and Q users update and verify the signed firmware download. Thank you to every researcher who reported issues, reproduced edge cases, reviewed fixes, and helped make this release stronger. blog.coinkite.com/coldcard-s…
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🚨 URGENT: The threat is still active. Follow the advisory for your model: update your COLDCARD, generate a new seed, then carefully move your funds. Please share this with less-online users who may not see it. xitter.cf/COLDCARDwallet/status/…
🚨URGENT COLDCARD SECURITY UPDATE Read carefully before acting. 👉Mk3 seed generated on 4.0.1+ without ≥50 private, independent dice rolls: begin a careful migration now. 👉Mk4/Mk5 <5.6.0 or Q <1.5.0Q: update first, generate a new seed, then migrate. blog.coinkite.com/entropy-te…
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Coinkite retweeted
Please treat this as urgent. Migrate your funds. Follow the advisory for your model, upgrade your device, generate a new seed, and carefully move your funds. Help spread the word, especially to people who are less online and may not see this update. The threat is still ongoing.
🚨URGENT COLDCARD SECURITY UPDATE Read carefully before acting. 👉Mk3 seed generated on 4.0.1+ without ≥50 private, independent dice rolls: begin a careful migration now. 👉Mk4/Mk5 <5.6.0 or Q <1.5.0Q: update first, generate a new seed, then migrate. blog.coinkite.com/entropy-te…
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COLDCARD FIRMWARE HOTFIX UPDATE CAN BRICK DEVICES A new bug has been identified in COLDCARD’s emergency firmware hotfix. While the update fixes the original entropy vulnerability, researchers say a temporary hardware RNG error can leave the device stuck on a fatal error screen before the PIN prompt, preventing users from accessing the upgrade menu.
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