Passed all 8 tests
We check each wallet from its code to the app on your device, asking these questions in order:
The answer is "yes".
If the answer were "no", we would mark it as "Fake" and the following would apply:
The answer is "no". We marked it as "Fake".
We did not ask this question because we failed at a previous question.
If the answer were "no", we would mark it as "Fake" and the following would apply:
The bigger wallets often get imitated by scammers that abuse the reputation of the product by imitating its name, logo or both.
Imitating a competitor is a huge red flag and we urge you to not put any money into this product!
The answer is "yes".
If the answer were "no", we would mark it as "Announced but never delivered" and the following would apply:
The answer is "no". We marked it as "Announced but never delivered".
We did not ask this question because we failed at a previous question.
If the answer were "no", we would mark it as "Announced but never delivered" and the following would apply:
Some products are promoted with great fund raising, marketing and ICOs, to disappear from one day to the other a week later or they are one-man side projects that get refined for months or even years to still never materialize in an actual product. Regardless, those are projects we consider “vaporware”.
The answer is "yes".
If the answer were "no", we would mark it as "Un-Released" and the following would apply:
The answer is "no". We marked it as "Un-Released".
We did not ask this question because we failed at a previous question.
If the answer were "no", we would mark it as "Un-Released" and the following would apply:
We focus on products that have the biggest impact if things go wrong and while pre-sales sometimes reach many thousands to buy into promises that never materialize, the damage is limited and there would be little definite to be said about an unreleased product anyway.
If you find a product in this category that was released meanwhile, please contact us to do a proper review!
The answer is "yes".
If the answer were "no", we would mark it as "Not a wallet" and the following would apply:
The answer is "no". We marked it as "Not a wallet".
We did not ask this question because we failed at a previous question.
If the answer were "no", we would mark it as "Not a wallet" and the following would apply:
If it’s called “wallet” but is actually only a portfolio tracker, we don’t look any deeper, assuming it is not meant to control funds. What has no funds, can’t lose your coins. It might still leak your financial history!
If you can buy Bitcoins with this app but only into another wallet, it’s not a wallet itself.
The answer is "yes".
If the answer were "no", we would mark it as "A wallet but not for Bitcoin" and the following would apply:
The answer is "no". We marked it as "A wallet but not for Bitcoin".
We did not ask this question because we failed at a previous question.
If the answer were "no", we would mark it as "A wallet but not for Bitcoin" and the following would apply:
At this point we only look into wallets that at least also support BTC.
The answer is "yes".
If the answer were "no", we would mark it as "Provided private keys" and the following would apply:
The answer is "no". We marked it as "Provided private keys".
We did not ask this question because we failed at a previous question.
If the answer were "no", we would mark it as "Provided private keys" and the following would apply:
The best hardware wallet cannot guarantee that the provider deleted the keys if the private keys were put onto the device by them in the first place.
There is no way of knowing if the provider took a copy in the process. If they did, all funds controlled by those devices are potentially also under the control of the provider and could be moved out of the client’s control at any time at the provider’s discretion.
The product cannot be independently verified. If the provider puts your funds at risk on purpose or by accident, you will probably not know about the issue before people start losing money. If the provider is more criminally inclined he might have collected all the backups of all the wallets, ready to be emptied at the press of a button. The product might have a formidable track record but out of distress or change in management turns out to be evil from some point on, with nobody outside ever knowing before it is too late. The answer is "yes".
If the answer were "no", we would mark it as "No source for current release found" and the following would apply:
The answer is "no". We marked it as "No source for current release found".
We did not ask this question because we failed at a previous question.
If the answer were "no", we would mark it as "No source for current release found" and the following would apply:
A wallet that claims to not give the provider the means to steal the users’ funds might actually be lying. In the spirit of “Don’t trust - verify!” you don’t want to take the provider at his word, but trust that people hunting for fame and bug bounties could actually find flaws and back-doors in the wallet so the provider doesn’t dare to put these in.
Back-doors and flaws are frequently found in closed source products but some remain hidden for years. And even in open source security software there might be catastrophic flaws undiscovered for years.
An evil wallet provider would certainly prefer not to publish the code, as hiding it makes audits orders of magnitude harder.
For your security, you thus want the code to be available for review.
If the wallet provider doesn’t share up to date code, our analysis stops there as the wallet could steal your funds at any time, and there is no protection except the provider’s word.
“Up to date” strictly means that any instance of the product being updated without the source code being updated counts as closed source. This puts the burden on the provider to always first release the source code before releasing the product’s update. This paragraph is a clarification to our rules following a little poll.
We are not concerned about the license as long as it allows us to perform our analysis. For a security audit, it is not necessary that the provider allows others to use their code for a competing wallet. You should still prefer actual open source licenses as a competing wallet won’t use the code without giving it careful scrutiny.
The product cannot be independently verified. If the provider puts your funds at risk on purpose or by accident, you will probably not know about the issue before people start losing money. If the provider is more criminally inclined he might have collected all the backups of all the wallets, ready to be emptied at the press of a button. The product might have a formidable track record but out of distress or change in management turns out to be evil from some point on, with nobody outside ever knowing before it is too late.Build Verifications
If you have a binary for a version that doesn't appear on the list, you can dropselect the file here to register it so somebody can verify its reproducibility:
Application information
Related to
App Description
Self-described as:
The Gold Standard of Bitcoin Custody
It features multisig, group wallets, coin control and hardware support. It also incorporates the latest advancements in Bitcoin such as Taproot, MuSig2 and Schnorr. Protect yourself from $5 wrench attacks with the feature called “Decoy Wallet”. Windows, Linux and macOS binaries are available.
Private key handling is discussed here.
From their FAQ:
Nunchuk is a self-custodial wallet developed using open standards (seed phrase backup is defined in BIP39, while wallet configuration backup is defined in BIP129). That means you always have complete control over your funds. As long as you maintain proper backups, you can recover your Nunchuk wallets elsewhere. Please click here to see our recovery guides.
It is also source-available and for verification
Multi Signature
Bitcoin allows to define addresses controlled by more than one private key. Two-of-three for example would mean that any two of a list of three private keys would be required to send coins from this address.
With keys from distinct devices or users, an attacker would have to compromise multiple devices or users at once. Multi signature thus allows to protect against one device catching a virus, one wallet having a backdoor (if the multi signature works across different providers’ wallets), one hardware wallet not being trusted (if hardware wallets can be used for multi signature), etc.
- There are no good standards yet for multi signature accounts. This might mean that an account that works with one provider’s wallet won’t load in any other wallet which can complicate recovery should that wallet go out of business.
- Using Multi Signature results in bigger and thus more expensive transactions.
- Using Multi Signature accounts makes it easier for blockchain analysis companies to follow the trail of a wallet.
- Multi Signature accounts require backups of additional descriptors, making financial loss from user error more likely.
Why we list it for this wallet
It features multisig, group wallets, coin control and hardware support.
Source: Store
Advanced UTXO Control
The wallet offers advanced control over which Unspent Transaction Outputs (UTXOs) are spent. This goes beyond simple coin selection — it may include the ability to freeze or exclude specific UTXOs (e.g., dusting attacks or tainted coins), label UTXOs, or select inputs manually. The user does not necessarily need full visibility of all UTXOs, but has meaningful control over what gets spent.
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Privacy: Prevent spending from UTXOs linked to unwanted transaction history, or avoid merging coins from different sources in one transaction.
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Dust protection: Mark suspicious incoming transactions as “do not spend” to avoid revealing your wallet’s full UTXO set.
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Fee optimization: Strategically select inputs to manage transaction size and fees.
Why we list it for this wallet
It features multisig, group wallets, coin control and hardware support.
Source: Store
Free and Open Source (FOSS)
The wallet’s source code is published under a license approved by the Open Source Initiative (OSI) — such as MIT, GPL, Apache, or AGPL — allowing anyone to inspect, modify, and redistribute it. This is a prerequisite for independent security audits and reproducible builds. Licenses that are merely “source available” but not OSI-approved (e.g., those with Commons Clause restrictions, commercial use prohibitions, or other non-free terms) do NOT qualify. Reproducible builds are not sufficient alone.
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Transparency: Anyone can verify what the code does — including whether it contains backdoors, bugs, or privacy-violating behavior.
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Community auditing: More reviewers means vulnerabilities are more likely to be found and fixed.
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Forkability: If the project is abandoned or goes rogue, the community can fork and continue it.
FOSS alone does not guarantee security. The released binary must also be reproducible from the public source to ensure users are actually running the code that was audited.
Why we list it for this wallet
GNU GENERAL PUBLIC LICENSE Version 3, 29 June 2007
Source: License
An issue has been opened at https://github.com/nunchuk-io/nunchuk-desktop/issues/86
Product page updated by Daniel Andrei R. Garcia
Community Opinions
These comments are contributed by Nostr users.
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Do your own research
In addition to reading our analysis, it is important to do your own checks. Before transferring any bitcoin to your wallet, look up reviews for the wallet you want to use. They should be easy to find. If they aren't, that itself is a reason to be extra careful.