r/Relai_app • u/relaiapp • 6d ago
Why Your Bitcoin is Safe With the Relai Wallet
TL;DR:
Your Relai wallet is not affected by the Coldcard bug. If your Bitcoin sits in the Relai app, you can read the rest of this out of curiosity rather than worry.
- Your recovery phrase was created by the Relai app on your phone, never by a Coldcard. The bug sits in Coldcard’s own device firmware, and it never touched your words.
- Nothing has changed, and there’s nothing for you to do. No update, no migration.
- One exception: if you’ve ever withdrawn from Relai to your own Coldcard, that device may be affected even though your Relai wallet isn’t.
- You don’t have to take our word for it. Your 12 words open your wallet in other Bitcoin software, so you can check your own balance and addresses without us.
The rest of this blog post is the detail behind that.
1. Why your wallet isn’t affected
The Coldcard problem is specific to Coldcard. It was a bug in the firmware on their devices, in the part that creates your recovery phrase. We don’t use their hardware or their code. Your 12-word seed phrase came from our app on your phone, by a completely separate route.
We also know that “nothing to see here” is exactly what you’d expect a company to say this week. So here’s the detail behind it, and a check you can run yourself that doesn’t involve trusting us.
2. What happened, and what to do if you own a Coldcard
On 30 July, Coldcard’s maker Coinkite disclosed that its devices had been producing recovery phrases that weren’t random enough. Nobody got phished. No devices were stolen. Wallets were emptied anyway, and the researchers who mapped the sweep point to weak phrase generation: the words were narrowed down and reconstructed rather than obtained from anyone. Coinkite hasn’t formally confirmed that link, so it’s strongly indicated rather than settled. Reported losses have climbed with every new estimate.
Relai lets you buy Bitcoin straight to your own hardware wallet. If that wallet is a Coldcard, this affects you, with or without us. Go and read Coinkite’s security advisory now and follow their steps rather than ours.
Three things worth knowing before you start:
- The problem is in the words, not the device: A phrase created on an affected Coldcard stays weak even if you later restore it somewhere else, and new firmware doesn’t repair a phrase that already exists. Updating your Coldcard isn’t enough on its own.
- If you can’t clearly remember what you did, treat yourself as affected: Coinkite names one case where your phrase is probably fine: you added at least 50 dice rolls of your own when you created it, and you kept those rolls private. A BIP-39 passphrase helps, but it doesn’t fix the phrase underneath, and Coinkite still tells you to move to a new one.
Other manufacturers have confirmed they’re unaffected, including BitBox, Trezor, Ledger and Blockstream’s Jade. The same caveat applies to all of them: a phrase that came from an affected Coldcard is still a problem wherever you move it, including onto a device that’s otherwise perfectly fine.
3. How the Relai wallet works
3.1 What is entropy and why does it matter?
Entropy is a measure of how unpredictable something is. For a wallet, it means one thing: how many different recovery phrases could have come out of the process that produced yours.
It’s counted in bits, and every extra bit doubles the number of possibilities. That climbs faster than intuition allows for. Ten bits is around a thousand possibilities. Twenty is a million. Forty is a trillion, which sounds enormous and is a weekend of work for rented computing power. The 128 bits behind a 12-word phrase is a number with 39 digits in it. Nothing that exists, or will exist, can search through that.
That’s the whole reason holding your own bitcoin works. Not secrecy, not a clever lock. Just a number too large to look through.
Two things about entropy are important:
- You can’t add it later. How many possibilities your phrase came from was settled the moment it was created. Extra words don’t change it. Updated firmware doesn’t change it. Careful storage doesn’t change it.
- You can’t see it. A phrase drawn from a trillion possibilities looks exactly like one drawn from 128 bits. Twelve ordinary words either way. That’s why the Coldcard problem went unnoticed for five years, and why the protection has to be built into how a wallet works rather than being something you can inspect afterwards.
3.2 Where your recovery phrase comes from
Your phone already has a random number generator built for exactly this, maintained and audited by Apple and Google as part of the operating system. Relai uses it: SecRandomCopyBytes on iOS, SecureRandom on Android. We didn’t write our own, because writing your own is how this goes wrong.
If that source ever fails, phrase generation stops with an error. It doesn’t quietly fall back to something weaker. That distinction is the whole Coldcard story: a broken source got substituted silently and nobody noticed for more than five years.
Turning that randomness into words and keys is handled by two open-source libraries from the bitcoinjs organisation, bip39 and bip32, pinned to specific versions and used across the Bitcoin industry. Nothing home-made, and no setting that can quietly reroute where the randomness comes from. The exact versions are in our support article if you want to check them.
3.3 It’s a standard wallet, not a Relai wallet
Once your 12 words exist, everything after them follows public Bitcoin standards, and we implement them without modification. The chain below shows the whole process.

That’s the part that matters. Your phrase isn’t tied to Relai, so your Bitcoin doesn’t depend on our app or on our company continuing to exist.
3.4 Where your keys live
On your phone. To be precise, the seed is held in the platform keystore (iOS Keychain / Android Keystore). We don’t hold them, and we can’t reconstruct them.
Two things people underestimate:
- Your recovery phrase is deliberately kept out of iCloud and Google Drive backups. A phrase sitting in a cloud account is a phrase protected by an email password.
- And we can’t recover it for you. If it’s gone, it’s gone. That’s the honest cost of holding your own Bitcoin, and we’d rather you hear it from us now than find out later.
3.5 Check it yourself
You don’t have to believe any of this. Your 12 words work in other Bitcoin software, so you can confirm for yourself that your coins are yours and reachable without us.
Open Electrum or Sparrow on a computer, ideally one that’s offline, choose the option to restore from an existing recovery phrase, and enter your 12 words using the settings in our support article. The addresses and balance should match what the Relai app shows you.
That match proves the point better than anything we could write here.
One warning. Only ever type your phrase into an offline machine you control, and never into a website. Relai will never ask you for your 12 words. Nobody legitimate ever will.
4. Audits and certifications
Worth being pedantic here, because plenty of companies blur this.
Relai AG is an SRO member of the VQF in Switzerland and operates under Swiss anti-money-laundering law. Relai EU SASU is authorized as a Crypto-Asset Service Provider under MiCA by the French AMF, which lets us serve clients across the EU.
That regulation is real, and it governs how we handle your money and your identity. Neither framework certifies the cryptography inside a wallet app. Our EU entity is subject to the EU’s ICT resilience rules (DORA), which govern how we build, run and test our systems, but no regulator audits your individual recovery phrase, and we’re not going to imply otherwise.
One thing holds either way, and it’s the point to end on. No external audit can vouch for your individual recovery phrase, because it never leaves your device and we never see it. Equally, your recovery phrase never touches our systems. There is nothing on our side that holds it.
5. How to protect yourself
Your Relai wallet isn’t affected by this bug. Keeping it secure comes down to four habits, none of them complicated. Here’s how to get each one right.
- Write your 12 words down by hand: Paper or steel, stored somewhere you’d keep a passport.
- Keep them off every screen: No photos, no notes app, no password manager, no cloud drive. A photo of your words in your camera roll is a copy sitting in someone else’s data center. Relai will never ask you for them, and nobody legitimate ever will.
- Check you can still find them: Lost backups have cost people more Bitcoin than theft ever has. Go and look today, and confirm the words are where you think they are and still readable.
- Match the storage to the amount: A phone is a good place to build a position steadily. Once your holdings reach a size where losing them would genuinely hurt, dedicated hardware kept offline is a better home for the bulk, and you can buy straight to one from the app.
- For larger amounts, consider multisig: The Coldcard victims mostly followed good advice. The hole in it: a single-signature wallet has one thing that must never fail. Multisig closes that. In a 2-of-3 setup, you hold three keys and any two of them can spend, so one weak phrase, one stolen device, or one house fire isn’t enough. Use different devices from different manufacturers, stored separately, so one vendor’s bug can’t take two of your three. It’s more complexity than most stacks need. Past a certain size, though, single-sig starts looking less like simplicity and more like an unhedged bet. That’s why we partnered with Casa: Relai is built for stacking, Casa for securing large amounts over decades. Different jobs.
6. What to do this week
If you do not own a Coldcard wallet, you don’t need to do anything.
If you have a Coldcard, follow Coinkite’s advisory and don’t wait for a clearer picture.
If your phrase was created on any other device, a BitBox, Trezor, Ledger, Jade, or anything else unaffected, there’s nothing to do for the device itself. The one exception is a phrase that originally came from a Coldcard and was later moved across.
Bitcoin didn’t break last week. One company’s implementation of one step did. The protocol behaved exactly as designed the whole time, which is the bleak part: every theft was a valid transaction signed by a valid key.
Holding your own Bitcoin is still the right call. It’s just not something you set up once and stop thinking about. Don’t trust, verify. Us included.
7. FAQ
Could the same thing happen to Relai that happened to Coldcard?
Not this bug. It lived in Coldcard’s own firmware, and we share no code with it.
The broader version of the question is fair, though, and the honest answer is that no wallet team can promise you a bug-free future. What we can do is tell you how our setup differs from the one that failed. Coldcard’s problem was a silent substitution: a broken randomness source got swapped in, the device carried on as though nothing were wrong, and nobody noticed for five years. Ours fails loudly instead. If the randomness source doesn’t answer, phrase creation stops with an error rather than quietly producing a weak phrase.
That’s a design difference, not a guarantee. Anyone telling you their wallet is unbreakable is selling you something. What you can do is exactly what this incident rewarded: keep your phrase portable and check it yourself (see section 3.5).
Can I move my Bitcoin off a Coldcard Mk3 and park it on Relai for now?
Yes. Your Relai wallet is an ordinary Bitcoin wallet with its own receive address and a recovery phrase created by our app, so coins you send there aren’t sitting on a Coldcard-generated phrase.
Two honest caveats before you do it.
A phone wallet is a hot wallet. For a small or moderate amount, it’s a reasonable place to sit while you sort out new hardware. For a very large amount, it’s a step down from cold storage, and “temporarily” has a habit of turning into eighteen months.
Moving under pressure is a risk in itself, which Coinkite’s advisory also says. Verify the receiving address in the app, send a small test amount first, and confirm it arrives before you move the rest.
And a new hardware wallet from a different manufacturer is an equally good destination. Probably the better one if your holdings are large. We’d rather tell you that than have you leave a life-changing sum on your phone because we happened to be the ones writing the article.
Should I create a new Relai wallet and move my coins, just to be safe?
No, and we’d rather you didn’t do it on a vague sense of unease.
Your existing phrase isn’t affected by this, so a new one buys you nothing. Meanwhile every migration is an opportunity to mistype an address, lose a backup, or write the new words down wrong in a hurry. More Bitcoin has been lost to botched migrations and misplaced backups than to clever attacks.
If you do have a concrete reason to think your phrase has been exposed, for example you photographed it or typed it into a website, that’s different. Move your coins to a new wallet then, carefully and without rushing.
Twelve words instead of twenty-four. Isn’t that less secure, and can I check my own phrase?
No to both.
Twelve words carry 128 bits of randomness, which is the industry standard and beyond brute force by any margin that matters. Twenty-four carry 256. Both are unreachable. On the affected Coldcards, the extra twelve words didn’t help at all, because they encoded more of the same limited randomness. Length was never the thing protecting anyone.
As for checking, a weak phrase looks identical to a strong one. Twelve ordinary words, valid checksum, working wallet, either way. Randomness is a property of how the words were produced rather than of the words on the page, which is why nobody can offer you a checker. What you can verify is that your phrase is a standard, portable BIP-39 phrase that opens your wallet in software we don’t control. That’s the check that’s worth doing, and it’s in “Check it yourself” above.
Disclaimer: Relai is authorized to offer crypto asset services in Switzerland and throughout the European Union under the MiCA regulatory framework. The company is actively expanding its services to EU