Cryobrick (@cryobrick) header
Cryobrick (@cryobrick) profile picture

Cryobrick

@cryobrick

Air-gapped Bitcoin cold storage on feature phones. Zero cost. Plausible deniability. Your keys, your control.

 mempool
geyser.fund/project/cryobrick?hero=geyserpromotion
Joined December 2025
  • Tweets197
  • Following56
  • Followers301
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Photo by Cryobrick (@cryobrick)Photo by Cryobrick (@cryobrick)Photo by Cryobrick (@cryobrick)Photo by Cryobrick (@cryobrick)Photo by Cryobrick (@cryobrick)Photo by Cryobrick (@cryobrick)Photo by Cryobrick (@cryobrick)Photo by Cryobrick (@cryobrick)
A glimpse of why CryoBrick as a project was born.
Bitshala (@bitshala_org) profile pictureBitshala
@bitshala_orgOct 31
Now on the Bitshala FOSS Stage at Bitmela: @apalok21 presenting @cryobrick What if an ordinary KaiOS feature phone could become an air-gapped Bitcoin signing device? CryoBrick's Compass wallet generates or restores a 12-word BIP39 seed, derives BIP84 Native SegWit addresses, and exports a zpub for use with a watch-only wallet. The watch-only wallet prepares a PSBT. The offline phone reviews the transaction, signs it with the private keys, and returns the transaction hex for broadcasting. Explore the code: github.com/cryobrick/compass
Image from Bitshala (@bitshala_org)
Image from Bitshala (@bitshala_org)
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New tools are being built for CryoBrick Version 2. Stay tuned.
apalok (@apalok21) profile pictureapalok@apalok21Oct 21
If you back-up your Bitcoin wallet on paper or a metal plate and God forbid it gets exposed. What do you want it to look like? One which reveals everything or the one which reveals nothing? There are about 丰10000 in this wallet. If you find the Seed Phrase they are yours.
Image from apalok (@apalok21)
Image from apalok (@apalok21)
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Cryobrick retweeted
Bitshala (@bitshala_org) profile picture
Bitshala
@bitshala_orgAug 10
Why an Indian Startup Built a Bitcoin Hardware Wallet Disguised as a $20 Feature Phone

Why an Indian Startup Built a Bitcoin Hardware Wallet Disguised as a $20 Feature Phone

Article · @bitshala_org
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apalok (@apalok21) profile picture
apalok@apalok21Aug 2
Standard hardware wallets scream "I hold Bitcoin". So we built @cryobrick, an open-source, air-gapped Bitcoin wallet disguised as a $20 feature phone. Our Substack article covers why we built CryoBrick. Link 👇 open.substack.com/pub/apalok…
Image from apalok (@apalok21)
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CryoBrick matches titans like BlueWallet & Electrum, giving the same 128-bit entropy output as dedicated chips. Want 100% trustless security? Code is open! We are currently working on adding manual dice & coin inputs. Build with us on GitHub: github.com/cryobrick/compass
GitHub - cryobrick/compass: Bitcoin wallet for KaiOS feature phones.

GitHub - cryobrick/compass: Bitcoin wallet for KaiOS feature phones.

Bitcoin wallet for KaiOS feature phones. Contribute to cryobrick/compass development by creating an account on GitHub.

github.com
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🔒 CryoBrick is safe & unaffected by recent wallet bugs! We use standard software CSPRNG via device-level system entropy to generate unique 128-bit keys. "System noise" means your phone captures random, microscopic clock-cycle timing variations between background tasks.
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🔒 Security Check: CryoBrick is fully safe and unaffected by the recent RNG vulnerabilities impacting hardware wallets. We generate 128-bit private keys using a robust software CSPRNG rooted in the device's system entropy, ensuring your wallet is entirely unique. (1/2)
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Want maximum security? You don't have to trust the phone's system. CryoBrick is 100% open-source on GitHub. If you want to customize your setup or add a feature to manually input physical dice rolls or coin flips, the code is completely open for you to build! (2/2)
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apalok (@apalok21) profile picture
apalok@apalok21Jun 6
Full version with better formatting is on Substack 👇 open.substack.com/pub/apalok… Would love to hear your thoughts in the comments there. Is MicroStrategy accelerating Bitcoin adoption or diluting its essence? #Bitcoin #MicroStrategy #SelfCustody
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Man, it’s easy to get black-pilled seeing all this dystopian stuff like VPN bans for age verification and the broader push toward digital IDs, social credit systems, and CBDCs. But seeing people all around the world tinkering to make Bitcoin better freedom money makes me bullish!
Bitcoin Lab (@bitcoinl4b) profile pictureBitcoin Lab
@bitcoinl4bApr 12
Cryobrick es un proyecto de cold storage Bitcoin airgapped que corre en feature phones basicos, esos celulares de teclado fisico que cuestan pocos dolares, el concepto es simple, el celular queda completamente desconectado de internet y funciona como hardware wallet de bajo costo, el app se llama Compass y permite crear y restaurar carteras Bitcoin sin ninguna conexion de red, costo de hardware cero, plausible deniability porque parece cualquier otra app, your keys your control, proyecto nuevo creado en diciembre de 2025, vale la pena seguirlo en cryobrick.com​​​​​​​​​​​​​​​​ 🧡⚡️
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Thanks @studentofbtc for the opportunity, it was an incredible experience participating in this Accelerator. The memories of interacting and working with these amazing group of builders will be cherished.
Santosh V | Bitmela Jaipur 🇮🇳 (@studentofbtc) profile pictureSantosh V | Bitmela Jaipur 🇮🇳
@studentofbtcApr 24
India is almost invisible on the global Bitcoin stage. We export talent but don’t build brands. This accelerator was an attempt to change that. Here is what 9 teams built over 12 weeks with 0.1 BTC on the line.....👇
Image from Santosh V | Bitmela Jaipur 🇮🇳 (@studentofbtc)
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The 12 weeks flew by. Lots of learning and lots of growing. Let's make it count.
Santosh V | Bitmela Jaipur 🇮🇳 (@studentofbtc) profile pictureSantosh V | Bitmela Jaipur 🇮🇳
@studentofbtcApr 23
India's first Bitcoin accelerator 🥳
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Cryobrick introduces an air-gapped Bitcoin cold storage solution that runs on basic feature phones. The phone remains completely disconnected from the internet and functions as a low-cost hardware wallet. Using the “Compass” app, users can create and restore wallets fully offline. No internet, near-zero cost, and strong plausible deniability.
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TFTC (@TFTC21) profile picture
TFTC
@TFTC21Apr 20
New open-source project Cryobrick converts cheap KaiOS feature phones into offline Bitcoin hardware wallets. Fully air-gapped and disguised as a Compass app.
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🚨 JIO PHONE BECOMES A BITCOIN VAULT! Cryobrick — an innovation by Indian developers that could replace hardware wallets. ✦ WHAT IS CRYOBRICK? ↳ Air-gapped cold storage for basic feature phones! ↳ Fully offline — no internet, no hacking ↳ Stealth mode — hidden like a normal app ↳ Made in India by local developers ✦ WHY IT’S SPECIAL? ↳ Low cost: Ledger/$150+, Trezor/$200 vs Jio Phone ₹699 ↳ Full custody with 12-word seed phrase ↳ Open source — transparent, no backdoors ✦ INDIA ANGLE ↳ 500M+ basic phone users can now carry a cold wallet in their pocket — no banks, no high costs Trezor $200. Ledger $150. Jio Phone ₹699. Game over for expensive hardware wallets?
Image from Crypto Aman (@cryptoamanclub)
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apalok (@apalok21) profile picture
apalok@apalok21Apr 15
Hello everyone, thanks for showing your love and support for CryoBrick. We really appreciate it. Order CryoBrick 👇 cryobrick.com/ Our GitHub 👇 github.com/cryobrick
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Cryobrick (@cryobrick) profile picture
Cryobrick@cryobrickApr 14
Replying to @elchiapp @bitcoinl4b
hey so JTAG does gets you the localStorage dump for sure, but even though your get that, the wallet mnemonic is encrypted with AES-256-GCM behind a mandatory 12+ char passwd (letters, num, and symbols). So after your 15 mins you've got an encrypted blob and a brute force prblem🙃
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Your old Nokia 3310 can now become a Bitcoin wallet. This open source wallet, Cryobrick, can be hidden on basic cellphones like any normal app, giving you private and offline custody. Play Snake and HODL on same device. - @RunwithBitcoin
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BlueWallet (@bluewalletio) profile picture
BlueWallet
@bluewalletioApr 13
So cool! Free Open Source Software undefeated.
Bitcoin Lab (@bitcoinl4b) profile pictureBitcoin Lab
@bitcoinl4bApr 12
Cryobrick es un proyecto de cold storage Bitcoin airgapped que corre en feature phones basicos, esos celulares de teclado fisico que cuestan pocos dolares, el concepto es simple, el celular queda completamente desconectado de internet y funciona como hardware wallet de bajo costo, el app se llama Compass y permite crear y restaurar carteras Bitcoin sin ninguna conexion de red, costo de hardware cero, plausible deniability porque parece cualquier otra app, your keys your control, proyecto nuevo creado en diciembre de 2025, vale la pena seguirlo en cryobrick.com​​​​​​​​​​​​​​​​ 🧡⚡️
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Bitshala (@bitshala_org) profile picture
Bitshala
@bitshala_orgApr 13
Bitshala’s BOSS Summit Summer 2026 🇮🇳

Bitshala’s BOSS Summit Summer 2026 🇮🇳

Article · @bitshala_org
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