Casa
@CasaHODL
Casa helps you secure your bitcoin. For the long term.
Take self-custody of your BTC and other assets with an inheritance plan.
Support: help@team.casa
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JUST IN: Casa's Chief Security Officer Jameson Lopp says Bitcoin faces no immediate threat from quantum computing. 👀
"We are orders of magnitudes away from a real usable quantum computer that can crack the algorithm that is used to secure your Bitcoin." 👏
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Social engineers pretending to be Google Support keep calling me, so I took the opportunity to create this educational video showcasing their tactics.
As attackers get more sophisticated, multi-vendor multisig reduces single points of failure and human error while leaving the keys with you.
Secure sovereignty comes from setups that assume things will go wrong, include a plan, and still leave you in control.
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Seeing reports of another round of snail mail social engineering letters from "Ledger" that try to trick you into scanning a QR code that takes you to software that steals your seed phrase.
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Learn more about multi-vendor multisig and how to protect your bitcoin for the long term:
Multi-vendor Multisig is not optional.
It is MANDATORY for self custody.
Compromised crypto hardware is nothing new. We've seen them as far back as 2018 with counterfeit Trezor One devices being sold.
@CasaHODL's security model has protected our clients against supply chain attacks since inception:
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Thoughts on the growing Ledger supply chain incident and security today:
It's a coincidence that this came to light so soon after the Coldcard incident, and doesn't look great for hardware wallets (even though this one doesn't appear to be Ledger's fault).
It's not a coincidence that security incidents in general are becoming more frequent in our industry and others.
The bad actors now have better tools than ever to try to steal your money. They can trivially look for software vulnerabilities with AI. They have mountains of data about you from a decade+ of unavoidable (for you) data leaks that helps them trick you with social engineering. And the value secured is juicy enough to attempt sophisticated supply chain attacks, because now we've seen that a successful attack on a random reseller can result in $100M+ stolen.
As regulations encourage more assets to be tokenized and the value of the whole ecosystem grows in general, we should expect more attention from sophisticated bad actors.
And we should also expect that there will continue to be vulnerabilities - whether that is in a hardware wallet or at a custodian.
This isn't only a problem in the crypto world either. It already affects traditional financial accounts in similar ways, and will probably get even wilder as people start connecting AI to their accounts.
The only answer is for you to assume things will be compromised and protect yourself accordingly by distributing your risk and eliminating single points of failure.
This is why we built Casa, and we can help you do it right.
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We are an official Ledger reseller and source the Ledgers that we provide to our clients directly from Ledger.
They are then stored in an access controlled location until being sent to Casa clients with the original Ledger packaging intact.
The Ledger supply chain incident is another reason why we designed Casa to integrate with many different hardware signers and vendors - to protect against vulnerabilities from any one device.
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Multi-vendor multisig protects you against supply chain attacks. @CasaHODL users unaffected.
The best thing you can do to protect your Bitcoin against this is to make sure that you are not reusing addresses that you have already spent from.
When you spend from a Bitcoin wallet on-chain, it reveals the public key(s) for that wallet. If the public key becomes known, then it could theoretically be reverse-engineered to crack the private key (in this hypothetical future where ECDSA is cracked). However when you deposit into a fresh address, it’s quite hard to correlate it to any specific wallet.
If you are using Casa, we manage this for you. When you send BTC from Casa, the change automatically goes to a new address in your wallet. Anytime you receive into Casa, we give you a fresh address without any deposits in it.
It's hard to say how likely it is that the core wallet cryptography underpinning Bitcoin and other cryptocurrencies could be cracked by non-quantum means; but you certainly can't discount the fact that OpenAI and others are solving a ridiculous amount of long-standing mathematics problems right now.
I think this risk results in further necessary investigation (and transparency?) around how some of the largest exchanges and custodians are managing address reuse. Unfortunately address reuse has historically been a best practice at some companies for managing wallets, because it helps avoid fat-fingering and other human mistakes. It’s possible the cryptographic breakthrough risk will start to outweigh the human mistake risk.
I also think this is another great argument for why the distribution of risk via self custody benefits the Bitcoin network as a whole. We saw with the Coldcard exploit that it took time to crack many individual wallets, giving people time to move assets to safety. The more centralized the custody of Bitcoin is, the more risk there is from a vulnerability in wallet cryptography.
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I think the Coldcard incident proved that the singlesig era is coming to an end. The tools used to successfully execute that attack will only get better, and trusting a single vendor with my stack just isn't something I would personally do in today's age.
Multi-vendor multisig is the answer for anyone wanting to self-custody now.
I work at @CasaHODL and will always advocate for the service because it allows you to be sovereign while still having somebody there every step of the way for setup, inheritance and ongoing support.
Many are technical enough to run a DIY multisig, and that might work for a lot of people.
The point here is that the risk is too high now to trust a single vendor when the tools are available to spread that risk across vendors in a way that any sort of attack or device malfunction to one or even two keys doesn't result in loss of funds.
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Two footguns most bitcoiners miss when setting up multisig according to @lopp.
Not backing up your wallet descriptor, and treating multi-vendor multisig as "set it and forget it.”
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Casa makes multisig easy.
Stay sovereign, stay safe, for the long term.
Someone breaks into your house, puts a gun to your head and demands your Bitcoin. You physically can't hand it over.
That's what proper custody looks like, and it's why one of the most radical ideas in Bitcoin is that it could bring silence to systemic violence.
Bitcoin won't stop crimes of passion. But no man is better than his incentives, and the uncomfortable truth is that crime does pay.
You can acquire assets through stealing and extortion, and physical property is what makes that profitable.
Gold in your closet can be seized by any man willing to threaten you for it.
Bitcoin is the first non-physical property that can be directly owned, which makes it far harder to seize by force. Domain names came close, but a centralized third party controls them, so they can be seized by legal coercion.
Bitcoin has no third party to coerce. Hold your own keys and you hold a bearer asset, like gold coins that aren't physically there.
Ownership comes down to keeping a secret.
That secret only protects you if you custody it properly. Write your private key (the password to your coins) on paper and lock it in a safe, and you've turned non-physical property back into physical property, seizable like the gold.
Multi-key solves this. Picture the nuclear launch scene, men with briefcases handcuffed to their wrists, 2 or 3 keys turned together in sequence before anything fires. You can hold Bitcoin the same way.
Break the private key into 3 pieces, or 5, or 7, called shards, and require a simple majority to move funds, 2 of 3 or 3 of 5, in a sequence you designate.
Then distribute them across your circle of trust. Your accountant holds one, your lawyer another, you hold the third.
Nothing moves without you, so you keep full control, and you gain redundancy, since losing one shard still leaves 2 of 3 between you and your accountant.
Which brings it back to the gun. You can't hand over what you can't move.
Pre-designate a safe word with your key holders, and when the thief forces you to call them, that word tells them to refuse. It's a custody schema as immune to coercion as anything you'll ever get, and it's what we trust with nuclear launch codes.
In a Bitcoinized multi-key world, crime pays less. Even warfare becomes less profitable, and therefore less prevalent, thanks to Bitcoin.
Bitcoin lowers the profitability of force, and humans do whatever is profitable, so the businesses built on force thin out.
There are only two ways to acquire wealth.
Making, where you produce and trade by consent, or taking, where you seize by force what makers have built.
Bitcoin tilts the landscape of human action toward making.
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Collaborative custody is great because it makes multisig easy and approachable, so people know they won’t do something wrong.
On a 3-of-5 you usually have more keys, which means your transaction process has more friction, on purpose, for additional security. One thing that is also great about collaborative custody with Casa, and often not mentioned, is the convenience.
If you are traveling and you are on a 3-of-5, you can carry a hardware wallet with you, and if your phone is also one of the signers, you can request the Casa Key for a signature and move funds without having to travel to one of the keys that should be geographically distributed.
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During his keynote at the C4 Security Summit @lopp from @CasaHODL talked how attackers are increasingly going after the people behind the systems.
Strong technology matters, but attackers often look for another way in, like through human behavior.
More Summit clips coming soon!
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Multi-vendor multisig means one bad key can't move funds on its own. Multisig alone does not repair a key with bad entropy.
If two of your three keys share the same entropy bug, they can share the same weakness.
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Bitcoin key generation depends on entropy: the randomness behind your seed.
When that randomness is weaker than expected, the seed is guessable no matter which device holds it or how long the phrase is.
July's Coldcard firmware disclosure made that concrete for a lot of bitcoiners. If you generated a seed on affected firmware and later moved it to a different wallet, the weakness moved with it.
Do you know where the randomness behind your seed came from?
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Setting up a multi-vendor 3-key vault is easier with someone walking you through it live.
Join the Casa team on Thursday, August 27 at 8:00am PT for a hands-on workshop where we will set up your first multi-vendor 3-key vault, step by step, with time for your questions along the way.
Bring your own device to follow along in real time, or watch and set yours up afterward.
Register free:
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Why does Casa store one key on your phone?
It’s about defense in depth. I’ve personally seen the phone key save ~tens of millions of dollars for people who have messed up with their hardware keys.
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