Bitcoin Wallet

1 minute read

Published:

Wallet Logo

This app was first launched on 19th June 2017 and currently has more than 1000000 downloads, a 4.0 stars rating from 9631 users and the latest APK (version 6.0.3) was from 30th January 2020 and is newer than the below reviewed version of the app.

Our analysis was done on 20th December 2019 based on data found in their Playstore description and their website and their source repository. We discuss the issue with verification with the provider here. In our GitLab this app is discussed in Issue #60.

We found these ways of contacting the developers:

Help spread awareness for build verifiability

Please help us spread the word, asking Bitcoin Wallet by Bitcoin.com to support verifiable builds via their Twitter!

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 bad coding practice. We cannot find and tell you all the dark secrets the wallet providers might have.

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

Update: As it turns out, they organize their releases in branches and don’t use tags. At the current state of the project we would give them the benefit of the doubt: For now it looks at least like open source but version tags are missing!

“Bitcoin Wallet” by Bitcoin.com claims to be non-custodial:

Our non-custodial wallet app lets nobody but you access the coins you own.

but can we verify that?

On the playstore description there is no word about it being open source. The website links to Android, iPhone and other versions where we find a “Source Code (zip)” but that contains only a two line text file.

Again on the website there is a link to wallet where we can’t find a link to source code neither.

Searching GitHub for com.bitcoin.mwallet yields Bitcoin-com / Wallet as a good candidate for an actual repository. A wallet with more than a million downloads should probably make it easier to find its source code. But let’s see if this is it.

If you have an issue with this wallet, you are sent to Copay which this appears to be a clone of, given “Copay” is found all over the place.

Given others can’t find the latest code since half a year and tags run only up to 5.6 (with the current code using 5.9):

$ git tag | grep ^5.
5.0-hotfix1
5.0-rc1
5.0-rc2
5.0-rc3
5.1-beta1
5.1-beta2
5.1-rc2
5.1-rc3
5.1-rc5
5.2-hotfix1
5.2-hotfix2
5.2-rc1
5.3-rc1
5.4-hotfix1
5.4-rc4
5.5-rc3
5.6-rc1
5.6-rc3
$ cat app-template/bitcoincom/appConfig.json | grep Version
  "fullVersion": "5.9-rc2",
  "androidVersion": "509001",

we give up our search and assume for now that the wallet went closed source, given the apk released is using version 5.13.3.

We are happy to update this website should the provider come around and clearly offer an up to date source code.

Our verdict: not verifiable.

Verdict Explained

Not verifiable: The provided Open 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.