# Bitcoin Wallet With Zero Seed-Phrase Exposure

Hey, I've been working on a secure Bitcoin wallet concept and would love your thoughts. Here's the core idea:

## Key Security Goals
- No seed phrases to lose or expose
- No private key material ever in app memory
- Hardware-backed security at every level
- Physical verification required for transactions

## Nuri.com Prototype
Registration, Login, Sign with Fingerprint Card
https://youtu.be/OtA2LiEpdz0

Fingerprint Registration
https://youtube.com/shorts/M9kvBfX7o6Q?feature=share

## Core Architecture
1. **Split-Key Approach**: Private key split between device and server using FROST (2-of-2 threshold signatures)
- Device share sealed inside Secure Enclave/StrongBox
- Server share held in HSM
- YubiKey Bio acts as gatekeeper that must be physically touched

2. **Spending Flow**
- YubiKey provides unlock secret via WebAuthn hmac-secret extension
- Device share used inside secure hardware (never in RAM)
- Server signs its portion after verifying YubiKey assertion
- App combines signatures for valid Taproot transaction

3. **Recovery Options**
- Backup passkeys (second YubiKey or platform passkey)
- Optional social recovery share (2-of-3 FROST)
- Emergency export option similar to Zengo's "Guaranteed Access"

## Protection Against Common Threats
- RAM scrapers: Only see public signature data
- Rogue dApps: Still need physical YubiKey touch
- Server breach: Only has Share B, cannot sign alone
- Lost devices: Multiple recovery paths available

All components would use open-source libraries like frost-secp256k1, BDK, and python-fido2 for implementation.

## Value Proposition

Nuri is “agnostic” and works with any software wallet that support hardware wallets. You can also connect your existing bank. It is an universal and agnostic biometric hardware security key that you can use with Google, Apple, Microsoft, and many more (https://fidoalliance.org/passkeys/)

a) a FIDO2 passkey enabled hardware security key, biometric passkey like yubikey.com (priced 100 USD)
b) a bitcoin hardware wallet like ledger.com (priced 100 USD)
c) a metal, biometric VISA/Mastercard “wearable” (priced 100 USD)

You can connect any existing VISA/Mastercard to Nuri. Or any of these banks: https://www.inviswearables.com/pages/supported-banks
Or, you can get a new Nuri Bank Card + IBAN Bank Account for free.
You can buy Bitcoin with Apple/Google Pay or Bank to Bitcoin Transaction.
You can pay your bills in Europe, US, Canada, Mexico from start on with Bitcoin to Bank transactions (here is an example: https://youtu.be/Xb8YUHQ9KzU)

## MPC

https://portalhq.io

## Passkey

https://www.mastercard.com/global/en/personal/payment-passkeys.html

## Links and References
- https://www.mermaidchart.com/raw/5218575b-0bfa-4f0d-9253-5dc5c4de8da2?theme=light&version=v0.1&format=svg
- https://www.mastercard.com/global/en/personal/payment-passkeys.html
- https://www.mermaidchart.com/app/projects/bb9914a7-5c02-4735-a741-6177a3bf1230/diagrams/5218575b-0bfa-4f0d-9253-5dc5c4de8da2/version/v0.1/edit
- https://turnkey.com
- https://portalhq.io
- https://www.mastercard.com/global/en/personal/payment-passkeys.html
- https://corporate.visa.com/en/products/visa-payment-passkey.html
- https://www.fireblocks.com/what-is-mpc/
- https://www.authsignal.com/
- https://fidoalliance.org/fido2/
- https://www.yubico.com/
- https://safety.google/authentication/passkey/
- https://tokenize.it
- https://lnvpn.net/
- https://rns.id/app

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