May Newsletter

MK4 reservations, NFC integration, P2TR support, gift cards, new European reseller & new team member

Coinkite

NVK

, and

cfunk

May 27, 2022

GM #CalculatorCrew,

In this ever-changing Bitcoin landscape, we're always working hard to build Sleep At Night Technology ™

We have some news you won't want to miss!

MK4 update

We are now 80% through shipping backorders 🚢🚢🚢

COLDCARDs MK4 are going out quick—now is the best time to get in line for reservations because the line keeps getting longer!

Reserve your MK4 now

COLDCARD Software Updates

Mk4’s Firmware version 5.0.3 has many updates, most notably for Taproot advocates. Folks will be happy to know that P2TR and Bech32m are now deployed on COLDCARD MK4 as of 5.0.3. For the older Mk3, we have recently shipping an update, Mk3’s 4.1.5, with the same P2TR features.

And then… on Friday we released 5.0.4 for Mk4! It has numerous improvements focusing on the needs of Bitcoin developers, such as support for RegTest (for use on your own Regression Testnet coins) and major upgrades to our testing setup. From outside contributors, we have improved encryption for HSM users, documentation fixes, and better reproducible builds.

Yes! THREE releases in just one month!

Read more about it in Bitcoin Optech’s newsletter:

Bitcoin Optech @bitcoinoptech

Changes to services and client software: - MyCitadel Wallet released - Tauros exchange supports Lightning - Lightning Multiplexer announced - Coldcard adds taproot sends

bitcoinops.orgBitcoin Optech Newsletter #200This week’s newsletter summarizes a discussion about the minimum change to Bitcoin’s Script language necessary to enable recursive covenants, examines a revised proposal to add an OP_TX opcode, and reviews research into adapting output script descriptors for hardware signing devices. Also included a…

Coinkite Gift-Cards

You’ve asked, we’ve listened: Coinkite virtual gift cards are here.

Pay in Bitcoin KYC-free and receive the unique codes directly to your preferred inbox.

COLDCARD @COLDCARDwallet

A lot of you asked us for a better way to anonymously buy family and friends COLDCARDs while having them sort our shipping by themselves... KYC free GiftCards 🎉

Coinkite @Coinkite

Checkout our new Coinkite Gift Cards! https://t.co/fsjrJd3ZZn https://t.co/zAVaoAiItV

NFC compatibility

Are you building mobile Bitcoin wallets?

Get TAPSIGNER samples

Offer NFC capabilities to your users by integrating with Coinkite’s TAPSIGNER and SATSCARD. We also offer white-label solutions.

DETERMINISTIC OPTIMISM @nvk

When we launched COLDCARD, PSBT had no compatible wallets. Now it's the standard. NFC will take some time to get integrated in wallets, that's Just how pushing new technology works... Low time preference development™ Let your favorite app wallet maker about it :)

COLDCARD Mk4’s Firmware 5.0.4 has NFC improvements, upgrade.

New European reseller

The privacy focused fulfillment service Copiaro is now shipping COLDCARDs MK4 from Germany. Along with BTCDirect.eu, they make up the list of our un-official European resellers.

Copiaro Stuttgart @copiaro

🚨 🚛💨 // Ab sofort verfügbar // Now available // 📦🚨 Die neue @Coinkite Coldcard MK4 #Bitcoin Hardware Wallet 😎⚡️🔥 copiaro.de/produkt/coldca…

copiaro.deDie neue Coldcard MK4 - Bitcoin Hardware Wallet - Version 2022 | CopiaroDie neueste Ausgabe von Coinkites Coldcard hat mit der im Jahr 2022 veröffentlichten Version MK4 ein ganz neues Level der Bitcoin-Sicherheit erreicht.

Top shout-outs

Dennis Porter @Dennis_Porter_

This is the most secure #Bitcoin hardware wallet on the planet. It’s not close. Been a happy customer for years and excited to get the brand new Mk4 from @COLDCARDwallet. Thanks @nvk 🙏🇨🇦

New tutorials from our community

burn the bridge @econoalchemist

The @COLDCARDwallet MK4 can handle #Bitcoin transactions up to 2MB in size. The MK3 could handle txs up to only 384kB. To demonstrate the difference in memory, I tried to sign a tx with 251 inputs using both the MK3 & MK4:

media.econoalchemist.comColdCard MK4 - 251UTXO testDemonstration of large transactions on the Coldcard MK3 vs. MK4. Learn more at: https://coldcard.com/docs/coldcard-mk4

Keep It Simple Bitcoin @KISBitcoin

How To Use @COLDCARDwallet Seed XOR. Create additional layers of security to protect your Bitcoin. The possibilities are ENDLESS. ✅What is Seed XOR ? ✅How to Split An Existing Seed ✅How to Combine Many Seeds

keepitsimplebitcoin.comHow To Use Coldcard Seed XOR | Keep It Simple BitcoinColdcard Seed Xor is a plausibly deniable way of storing secrets in two or more parts that look & behave like the original secret. One 24-word seed phrase becomes two or more parts.

In other news…

BitcoinBinary.org has now a Build Bot and the 5K bounty was claimed 🎉
Help us add more Bitcoin notable dates to Bitcoin.holiday
BitcoinBounties.org now keeps a sum of all available bounties, 10+ BTC up for grabs.
New team member: Welcome to C Funk a.k.a. C-to-tha’Funk for joining the ranks of Coinkite as business development manager! Since 2017, C Funk has been committed to orange-pilling the world by helping Bitcoin start-ups with building communities and developing partnerships. DM her on Twitter, Telegram, LinkedIn or Reddit to inquire about sponsorship and partnerships opportunities with Coinkite.
Get tipped in Bitcoin on COLDCARD Telegram channel for great contributions