Casa
Casa Technical Briefing
Published June 8, 2021
Supported by Costanoa Ventures and IowaEDA
Overview
Casa demos its personal key-manager product for Bitcoin self-custody — a safe, visually-consumer-first way to hold Bitcoin private keys without falling off the "one key, one pool of coins" cliff that has already lost an estimated 4M of Bitcoin\'s 21M total supply. At Casa\'s highest security tier, five keys protect one Bitcoin pool (mobile phone, three hardware wallets, one emergency Casa-held key) under a 3-of-5 multi-sig — losing any one key doesn\'t risk your funds. A separate "checking account" uses a single mobile key for fast spending. The send flow shows the multi-sig in action: the phone signs first, Casa emails a prompt to plug in a Trezor or Ledger for the second signature, and a third hardware approval broadcasts the transaction to Bitcoin\'s network. QR-code-based signing on next-gen hardware wallets will eliminate the email step. Casa\'s replace-a-lost-key flow skips seed-phrase recovery entirely — mark the key compromised, add a new hardware device, and transfer funds with the remaining healthy keys. Premium service tiers offer concierge-style support for high-net-worth holders.
0:00 Introduction to Casa
Nick introduces Casa as a safe and simple way to hold Bitcoin private keys. Of Bitcoin's 21M total supply, an estimated 4M coins have been lost in a decade — mostly to mistakes, not theft — blocking mass adoption for anyone unwilling to risk their savings.
1:00 The private-key tradeoff
Bitcoin private keys give you sole control of your money without needing a bank — but if you lose the key, you lose everything. The common workaround (leaving keys with Coinbase) trades control for security, which Casa is trying to unbundle.
1:30 Casa as a personal key manager
Casa is a new kind of product — a personal key manager that lets you safely manage your own Bitcoin private keys. Its core idea: instead of one key, use multiple keys to protect one pool of Bitcoin, so losing a key doesn't mean losing the money.
2:30 Casa's 5-of-3 multi-sig setup
At the highest security tier Casa holds five keys securing one Bitcoin pool: one on your phone, three on hardware wallets (Trezor/Ledger), and one emergency key held by Casa. Multi-sig means any three of five keys are enough to spend.
3:30 Checking account — single mobile key
For everyday spending, Casa offers a checking-style wallet with a single mobile key — easy one-tap sends from your phone without pulling out hardware devices, paired with the multi-sig vault for savings.
4:30 Sending 1 BTC — three signatures
Sending Bitcoin from the vault: the phone key adds the first signature, Casa emails a prompt to plug in your Trezor/Ledger for the second, and a third hardware signature finalizes the spend. Stolen phone alone cannot move funds.
5:30 QR-code signing on next-gen hardware
New hardware wallets with screens let Casa skip the email step entirely — sign by scanning a QR code into the hardware device and return the signature via QR, a major UX upgrade.
6:30 Replacing a lost key without a seed phrase
With multi-sig, losing one key doesn't require seed-phrase recovery. Mark the key as lost or compromised in-app, add a new hardware wallet, and transfer funds to a healthy new wallet using three of the remaining keys.
8:30 White-glove help for high-balance holders
Casa offers premium service tiers with concierge-style support — call a human for help — positioned as the opposite of Coinbase's days-long support queue, specifically for high-net-worth Bitcoin holders.
Presented by Nick Neuman and Michael Haley — Casa · website
Topics: Custody, Wallets, Crypto Infrastructure
