Passed 7 of 10 tests
We check each wallet from its code to the app on your device, asking these questions in order:
We stopped asking questions after we encountered a failed answer.
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 "Leaks Keys" and the following would apply:
The answer is "no". We marked it as "Leaks Keys".
We did not ask this question because we failed at a previous question.
If the answer were "no", we would mark it as "Leaks Keys" and the following would apply:
Some people claim their paper wallet is a hardware wallet. Others use RFID chips with the private keys on them. A very crucial drawback of those systems is that in order to send a transaction, the private key has to be brought onto a different system that doesn’t necessarily share all the desired aspects of a hardware wallet.
Paper wallets need to be printed, exposing the keys to the PC and the printer even before sending funds to it.
Simple RFID based devices can’t sign transactions - they share the keys with whoever asked to use them for whatever they please.
There are even products that are perfectly capable of working in an air-gapped fashion but they still expose the keys to connected devices.
This verdict is reserved for key leakage under normal operation and does not apply to devices where a hack is known to be possible with special hardware.
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 "Bad Interface" and the following would apply:
The answer is "no". We marked it as "Bad Interface".
We did not ask this question because we failed at a previous question.
If the answer were "no", we would mark it as "Bad Interface" and the following would apply:
These are devices that might generate secure private key material, outside the reach of the provider but that do not have the means to let the user verify transactions on the device itself. This verdict includes screen-less smart cards or USB-dongles.
The wallet lacks either a screen or buttons or both. In consequence, crucial elements of approving transactions is being delegated to other hardware such as a general purpose PC or phone which defeats the purpose of a hardware wallet. For big exit scams, a companion app could always request two signatures - one for the coffee you are paying and a second to empty your wallet completely. The former could be broadcast while the latter only gets collected for later use.
Another consquence of a missing screen is that the user is faced with the dilemma of either not making a backup or having to pass the backup through an insecure device for display or storage.
The software of the device might be perfect but this device cannot be recommended due to this fundamental flaw.
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
Check your file
Application information
Disclaimer: The WalletScrutiny project is sponsored by Spiral, a subsidiary of Block.
This product has a companion app:
Bitkey - Bitcoin Wallet . For the 2026 hardware revision with OLED touchscreen, see
Update, 2024-03-04: The Bitkey Hardware Wallet is now officially released
Description
The Bitkey hardware device is made from corian and stainless steel. Its security features include key handling, biometric authentication, 2 of 3 multisignature transactions, cloud backups and social recovery mechanisms.
Owners of the Bitkey can invite trusted contacts to assist in the recovery of their keys in the event of phone and device loss. Rather than using the seed phrase recovery model by itself, Bitkey utilizes social recovery. NFC technology is meant to ensure that transaction authentication would always involve the presence of two devices, or two private keys. The third key is held by Square in their servers.
BitKey’s approach to self-custody
Users can also set spending thresholds. Spending more than the threshold would need another key.
We’ll require two of those three keys to authorize any transaction; importantly, we’ll only use Square’s key to authorize transactions requested by the customer if either their hardware wallet is used or if the transaction amount is below a customer-configured spending limit. This will mean more capability in one wallet
Analysis
Setup
- Download the Bitkey app.
- Open the app and choose “Set up new wallet.”
- Pair the hardware device with the app using NFC (no initial charging required).
- If NFC issues arise, ensure NFC is enabled on the phone.
- Enroll the user’s fingerprint following the app’s prompts.
- Complete cloud backup for iOS with iCloud or for Android with Google account.
- Establish recovery contact methods, with email as a mandatory channel.
- Customize transaction and product update notifications.
- Agree to the terms of service.
Multisignature
- There are three keys involved: one in the hardware wallet, one in the mobile app, and one in Square’s servers.
- Square provides the security for the server-held key.
- Transaction authorization requires two out of three keys.
- Square’s key is used only when:
- The customer requests a transaction and uses their hardware wallet, or
- The transaction is below a set spending limit configured by the customer.
Recovery Options
Here are the available recovery options offered by Bitkey.
Cloud recovery: Lost/Replaced phone with cloud backup available
- Lost/Replaced phone without cloud backup available
- Lost/Replaced hardware device with/without cloud backup available
Cloud Health Check: Lost/Replaced Cloud account
Trusted Contacts: Lost/Replaced BOTH hardware device and phone, near the same time
- Emergency Access Kit: Bitkey app unavailable in app store(s)
Fingerprint Scanner
- The fingerprint scanner is used to unlock the device and sign transactions.
Verdict
Bitkey innovates with a combination of social recovery, biometrics, NFC and multisignature technology. From a strict security standpoint however, we cannot ignore the fact that the device does not have a display for users to verify outgoing transactions. It acknowledges this here:
Storing bitcoin shouldn’t require buying a second phone, or anything close to that. We want customers to be able to use the computer they already take everywhere,(…) From a hardware perspective, we think that means leaving out whatever we can – starting with a display. Before we make that decision, though, we’ll be reaching out to security experts across the community to make sure this is the right tradeoff for our customers.
Absent a button and a screen, the device would be engaging in blind-signing. Users would be trusting the mobile device, and the app that is preparing the transaction. Attackers who have access to manipulating the software can just as easily alter details such as the address where the bitcoin would be sent.
For this reason, we give the device a verdict of having a bad interface.
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
Software is licensed by Block, Inc. under the following MIT License (the "License"), and with no warranties or guarantees.
Source: GitHub README
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
Bitkey's 2-of-3 multisig setup is built into every wallet. You hold two keys: one on your Bitkey device and one in the app . A third is encrypted on a server and can't be used without one of your other keys.
Source: Website
Fingerprint Authentication
Fingerprint authentication in Bitcoin wallets enhances security by adding a biometric layer to the access control mechanisms. This feature leverages the unique patterns of a user’s fingerprint to grant access to the wallet, making unauthorized access significantly more difficult. Biometric authentication is generally faster and more convenient than traditional methods like passwords or PINs, as it eliminates the need to remember complex combinations. This form of authentication is particularly useful in mobile wallet applications, where ease of access and security are paramount. Fingerprint authentication minimizes the risk of phishing or brute force attacks that typically target password-based systems. Furthermore, it can be combined with other forms of security measures, like PINs or passwords, to create a multi-factor authentication system for added security. The use of biometric data, however, raises concerns regarding privacy and data security. Users must be assured that their biometric data is stored securely and not vulnerable to unauthorized access or breaches.
- Enhanced security through a unique, non-replicable form of identification
- Convenience and speed of access compared to traditional methods
- Reduced risk of phishing and brute force attacks
Potential privacy concerns and dependency on device hardware capabilities.
Why we list it for this wallet
Fully Integrated Bitkey's app and hardware were built together from the ground up to eliminate the complexities of traditional hardware wallets. Compare prices across exchange partners before you buy, and relax knowing Bitkey's biometric hardware can protect every transaction in the app.
Source: Website
NFC (Near Field Communication)
The wallet supports Near Field Communication (NFC) for wireless interaction with hardware wallets, payment terminals, or signing cards. NFC enables tap-to-sign or tap-to-pay functionality over a very short range (typically a few centimeters) without cables or QR codes.
- Convenience: Quick tap interaction — no cables to connect or QR codes to scan.
- Hardware wallet compatibility: Some hardware signing cards communicate exclusively via NFC.
- Requires NFC hardware on both devices.
- Very short range limits usability compared to QR-based air-gapped setups.
Why we list it for this wallet
Pair the hardware device with the app using NFC (no initial charging required).
Source: Website
Product page updated by Daniel Andrei R. Garcia
Community Opinions
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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.