This app was first launched on 1st March 2011 and currently has more than 1000000 downloads, a 4.0 stars rating from 22259 users and the latest APK (version 7.69) was from 26th March 2020.
Our analysis was done on 29th March 2020 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.
We found these ways of contacting the developers:
- Review of version 7.68 on 20th March 2020 (verdict: verifiable)
- Review of version 7.61 on 14th March 2020 (verdict: verifiable)
- Review of version 7.53 on 16th February 2020 (verdict: verifiable)
- Review of version 7.47 on 24th January 2020 (verdict: verifiable)
- Review of version 7.45 on 18th January 2020 (verdict: verifiable)
- Review of version 7.43 on 7th January 2020 (verdict: verifiable)
- Review of version 7.23 on 15th November 2019 (verdict: verifiable)
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.
For the latest version the test script: came to these results:
Results for appId: de.schildbach.wallet apkVersionName: "7.69" apkHash: c3e8495a55da4dffbdd969b77dccf957bcb816a4469e8adc22751fdfc8579ba4 Diff: Files /tmp/fromPlay_de.schildbach.wallet_469/apktool.yml and /tmp/fromBuild_de.schildbach.wallet_469/apktool.yml differ Only in /tmp/fromPlay_de.schildbach.wallet_469/original/META-INF: BITCOIN-.RSA Only in /tmp/fromPlay_de.schildbach.wallet_469/original/META-INF: BITCOIN-.SF Files /tmp/fromPlay_de.schildbach.wallet_469/original/META-INF/MANIFEST.MF and /tmp/fromBuild_de.schildbach.wallet_469/original/META-INF/MANIFEST.MF differ
That is what we expected to again give his app the verdict verifiable.
Verifiable: The provided Open Source Code matches the app released on Google Play
The app can be independently verified. If the provider puts your funds at risk on purpose or by accident, security researchers can see this if they care to look. It also means that inside the company engineers can verify that the release manager is releasing the app based on code known to all engineers on the team. A scammer would have to work under the potential eyes of security researchers. He would have to take more effort in hiding any exploit.
"Verifiable" does not mean "verified". There is good reason to believe that security researchers as of today would not detect very blatant backdoors in the open source code before it gets exploited, much less if the attacker takes moderate efforts to hide it.