BRD Bitcoin Wallet. Cryptocurrency, Bitcoin Cash

Published:

Wallet Logo

This Android app was first launched on 21st July 2016 and currently has more than 1000000 downloads, a 3.9 stars rating from 12453 users and the latest release is version 4.4.2.

Our last analysis was done on 16th December 2019 based on data found in their Google Play description and their website and their source repository. We discuss issues with the provider here.

We found these ways of contacting the developers:

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Disclaimer

The following Analysis is not a full code review! We plan to make code reviews available in the future but even then it will never be a stamp of approval but rather a list of incidents and questionable coding practice. Nasa sends probes to space that crash due to software bugs despite a huge budget and stringent scrutiny.

Do your own research!

Try out searching for "lost bitcoins", "stole my money" or "scammers" together with the wallet's name, even if you think the wallet is generally trustworthy. For all the bigger wallets you will find accusations. Make sure you understand why they were made and if you are comfortable with the provider's reaction.

The Analysis

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.

Verdict Explained

Not verifiable: The provided Source Code could not be verified to match the app released on Google Play.

This verdict means that the provider did share some source code but that we could not verify that this source code matches the released app. This might be due to the source being released later than the app or due to the provided instructions on how to compile the app not being sufficient or due to the provider excluding parts from the public source code. In any case, the result is a discrepancy between the app we can create and the app we can find on GooglePlay 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 app 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 app 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 app 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.