Our wallet review process
We examine wallets starting at the code level and continue all the way up to the finished app that lives on your device. Provided below is an outline of each of these steps along with security tips for you and general test results.
Custody
Self-custodial: The user holds the keys
But This product was removed from the platform.
As part of our Methodology, we ask: Is the product self-custodial?
The answer is "yes". The user has control of their own keys.
Read more
Released
22nd June 2014
Application build
Without public source of the reviewed release available, this product cannot be verified!
See the last Issue we created.
Passed 5 of 9 tests
We answered the following questions in this order:
We stopped asking questions after we encountered a failed answer.
The answer is "yes".
If the answer was "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 was "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 was "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 was "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 was "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 was "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 was "no", we would mark it as "Can't send or receive bitcoins" and the following would apply:
The answer is "no". We marked it as "Can't send or receive bitcoins".
We did not ask this question because we failed at a previous question.
If the answer was "no", we would mark it as "Can't send or receive bitcoins" and the following would apply:
If it is for holding BTC but you can’t actually send or receive them with this product then it doesn’t function like a wallet for BTC but you might still be using it to hold your bitcoins with the intention to convert back to fiat when you “cash out”.
All products in this category are custodial and thus funds are at the mercy of the provider.
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 was "no", we would mark it as "Custodial: The provider holds the keys" and the following would apply:
The answer is "no". We marked it as "Custodial: The provider holds the keys".
We did not ask this question because we failed at a previous question.
If the answer was "no", we would mark it as "Custodial: The provider holds the keys" and the following would apply:
A custodial service is a service where the funds are held by a third party like the provider. The custodial service can at any point steal all the funds of all the users at their discretion. Our investigations stop there.
Some services might claim their setup is super secure, that they don’t actually have access to the funds, or that the access is shared between multiple parties. For our evaluation of it being a wallet, these details are irrelevant. They might be a trustworthy Bitcoin bank and they might be a better fit for certain users than being your own bank but our investigation still stops there as we are only interested in wallets.
Products that claim to be non-custodial but feature custodial accounts without very clearly marking those as custodial are also considered “custodial” as a whole to avoid misguiding users that follow our assessment.
This verdict means that the provider might or might not publish source code and maybe it is even possible to reproduce the build from the source code but as it is custodial, the provider already has control over the funds, so it is not a wallet where you would be in exclusive control of your funds.
We have to acknowledge that a huge majority of Bitcoiners are currently using custodial Bitcoin banks. If you do, please:
- Do your own research if the provider is trust-worthy!
- Check if you know at least enough about them so you can sue them when you have to!
- Check if the provider is under a jurisdiction that will allow them to release your funds when you need them?
- Check if the provider is taking security measures proportional to the amount of funds secured? If they have a million users and don’t use cold storage, that hot wallet is a million times more valuable for hackers to attack. A million times more effort will be taken by hackers to infiltrate their security systems.
The answer is "yes".
If the answer was "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 was "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.The answer is "yes".
If the answer was "no", we would mark it as "Failed to build from source provided!" and the following would apply:
The answer is "no". We marked it as "Failed to build from source provided!".
We did not ask this question because we failed at a previous question.
If the answer was "no", we would mark it as "Failed to build from source provided!" and the following would apply:
Published code doesn’t help much if the app fails to compile.
We try to compile the published source code using the published build instructions into a binary. If that fails, we might try to work around issues but if we consistently fail to build the app, we give it this verdict and open an issue in the issue tracker of the provider to hopefully verify their app later.
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 was "no", we would mark it as "Not reproducible from source provided" and the following would apply:
The answer is "no". We marked it as "Not reproducible from source provided".
We did not ask this question because we failed at a previous question.
If the answer was "no", we would mark it as "Not reproducible from source provided" and the following would apply:
Published code doesn’t help much if it is not what the published binary was built from. That is why we try to reproduce the binary. We
- obtain the binary from the provider
- compile the published source code using the published build instructions into a binary
- compare the two binaries
- we might spend some time working around issues that are easy to work around
If this fails, we might search if other revisions match or if we can deduct the source of the mismatch but generally consider it on the provider to provide the correct source code and build instructions to reproduce the build, so we usually open a ticket in their code repository.
In any case, the result is a discrepancy between the binary we can create and the binary we can find for download and any discrepancy might leak your backup to the server on purpose or by accident.
As we cannot verify that the source provided is the source the binary was compiled from, this category is only slightly better than closed source but for now we have hope projects come around and fix verifiability issues.
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.Application build test result
(Analysis from Android review)
Update 2022-11-02: The repository has not been updated in a long time and the provider has not reacted to our enquiry to do so. This product is not verifiable.
Update 2022-04-07: This product’s provider appears to be partnering with Coinbase and with their latest update they now encourage and help their users to migrate to Coinbase Wallet, a browser extension based self-custodial wallet. The article is not (yet) talking about BRD Bitcoin Wallet Bitcoin BTC being in sunset mode or obsolete but some consolidation appears to be going on.
Update 2021-06-29: The provider informed us that the latest code can be found in a new repository. Apparently the new repository is a fork of the old repository where they changed the license from open source to some look-dont-touch license. For us, both provide the same degree of transparency so we have to revert the last change in verdict. This app does indeed share up to date source code although the git tag and the Play Store version name do differ.
Update 2021-06-27: As pointed out here, the provider stopped updating the public source repository and thus is to be considered closed source. The current version on the Play Store is 4.10.0 from yesterday. The latest version available on their GitHub is 4.9.1.1 from 2021-03-03.
This wallet claims not to be custodial and we found its supposed source code but we found no claim of verifiability and so verification was difficult.
Update: The team reacted quickly to our reach-out after our first analysis via this issue on their GitHub.
Now we find a tag build-3.14.3.3
and can try to compile that:
$ git tag | grep 3.14.3
build-3.14.3.3
$ git checkout build-3.14.3.3
...
HEAD is now at a332b4d5 Merge branch 'pablobu/DROID-1497' into 'release/3.14.3'
$ git submodule update --init --recursive
$ docker run -v $PWD:/mnt -it beevelop/cordova bash
root@e34a31867b99:/tmp# cd /mnt/
root@e34a31867b99:/mnt# yes | $ANDROID_HOME/tools/bin/sdkmanager "platforms;android-28"
root@e34a31867b99:/mnt# ./gradlew :app:assemble
root@e34a31867b99:/mnt# ls app/build/outputs/apk/brd/release/*.apk
brd-release-3.14.2.1.apk output.json
Now that doesn’t look promising, given we need version 3.14.3
and indeed the
diff is huge and goes across many code files.
The content of AboutActivity for example confirms its the wrong version. Many of the differences look harmless like this:
diff -r fromBuild/smali/com/breadwallet/presenter/activities/settings/AboutActivity.smali fromPlayStore/smali/com/breadwallet/presenter/activities/settings/AboutActivity.smali
157c157
< const-string v4, "3.14.2"
---
> const-string v4, "3.14.3"
But with these diffs we can’t give it a pass:
Binary files fromBuild/lib/arm64-v8a/libcore.so and fromPlayStore/lib/arm64-v8a/libcore.so differ
Binary files fromBuild/lib/armeabi-v7a/libcore.so and fromPlayStore/lib/armeabi-v7a/libcore.so differ
Binary files fromBuild/lib/x86/libcore.so and fromPlayStore/lib/x86/libcore.so differ
Binary files fromBuild/lib/x86_64/libcore.so and fromPlayStore/lib/x86_64/libcore.so differ
Diffoscope yields user directories in its 397662 lines of diff:
│ ├── readelf --wide --decompress --hex-dump=.rodata {}
│ │ @@ -1,7610 +1,7450 @@
│ │
│ │ Hex dump of section '.rodata':
│ │ - 0x001622e0 2f557365 72732f61 6a762f64 6576656c /Users/ajv/devel
│ │ - 0x001622f0 2f627265 61647761 6c6c6574 2d616e64 /breadwallet-and
│ │ - 0x00162300 726f6964 2f636f72 652f4a61 76612f43 roid/core/Java/C
│ │ - 0x00162310 6f72652f 7372632f 6d61696e 2f637070 ore/src/main/cpp
│ │ - 0x00162320 2f636f72 652f7375 70706f72 742f4252 /core/support/BR
This looks like NDK being the culprit for part of the diff, apart from it being the wrong version. Hopefully with Docker this can be improved.
Our verdict
We conclude that we hope for a quick resolution of the issues but for now this wallet remains not verifiable.
Tests performed by Leo Wandersleb
Previous application build tests
7th April 2022 | 4.10.0 | |
27th June 2021 | 4.10.0 | |
21st December 2020 | 4.9.0.3 |
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.