Wallet Logo

BTC.com – Bitcoin Wallet

latest release: 4.4.9 last analysed  3rd March 2021
Not reproducible from the source provided
3.9 ★★★★★
8th September 2015

Published:

Our last analysis is based on data found in their App Store description and their source repository.
details below 

Help spread awareness for build reproducibility

Please help us spread the word, asking BTC.com – Bitcoin Wallet to support reproducible builds  via their Twitter!

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.

If you find something we should include, you can create an issue or edit this analysis yourself and create a merge request for your changes.

The Analysis

This app claims:

  • Bitcoin (BTC) & Bitcoin Cash (BCH) support
  • 100% control of your private keys

so it’s a self-custodial BTC wallet. And it’s also open source:

This wallet is a free and open source software. You can view the code on GitHub at http://github.com/blocktrail/blocktrail-wallet.

That’s great but can we reproduce the app?

On Google Play the “current version” is 4.4.7 and on GitHub we find a tag for that.

The Readme.md also contains compile instructions. Let’s do this:

$ git clone https://github.com/blocktrail/blocktrail-wallet
$ cd blocktrail-wallet/
$ git checkout v4.4.7 
$ docker run -it --volume $PWD:/mnt --workdir /mnt --rm beevelop/cordova bash
root@f74eea3c3d23:/mnt# npm install -g npm # make sure npm is latest version
root@f74eea3c3d23:/mnt# npm_config_engine_strict=false npm install -g ionic@4.3.1 cordova@8.1.2 gulp
root@f74eea3c3d23:/mnt# npm install
(node:39) ExperimentalWarning: The fs.promises API is experimental
npm ERR! code 1
npm ERR! path /mnt/node_modules/@sentry/cli
npm ERR! command failed
npm ERR! command sh -c node scripts/install.js
npm ERR! Error: Command failed: /mnt/node_modules/@sentry/cli/sentry-cli --version
npm ERR! error: Failed to load .sentryclirc file from the home folder.
npm ERR!   caused by: Permission denied (os error 13)

npm ERR! A complete log of this run can be found in:
npm ERR!     /root/.npm/_logs/2021-03-05T02_14_24_795Z-debug.log

so as .sentryclirc apparently is a file that has to be in the home folder with some sort of credentials, we probably can’t build the project without this further step and conclude the app is not verifiable.

Apart from there being source code it is worth mentioning that the app was not updated since July 2019 and many 1* ratings complain about financial loss!

Verdict Explained

Not reproducible from the source provided

The app provider also shares code but we could so far not verify that the published code matches the published app!

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.