This app was first launched on 1st July 2013 and currently has more than 1000000 downloads, a 4.3 stars rating from 8597 users and the latest APK is version 18.104.22.168.
We found these ways of contacting the developers:
- Website: wallet.mycelium.com/
- Twitter: @MyceliumCom
- Facebook: myceliumcom
- Reddit: r/mycelium
- LinkedIn: company/mycelium
- Review of version 22.214.171.124 on 17th June 2020 (verdict: reproducible)
- Review of version 126.96.36.199 on 17th June 2020 (verdict: reproducible)
- Review of version 188.8.131.52 on 6th May 2020 (verdict: reproducible)
- Review of version 184.108.40.206 on 6th May 2020 (verdict: reproducible)
- Review of version 220.127.116.11 on 27th April 2020 (verdict: nonverifiable)
- Review of version 18.104.22.168 on 20th March 2020 (verdict: reproducible)
- Review of version 22.214.171.124 on 20th March 2020 (verdict: reproducible)
- Review of version 126.96.36.199 on 17th February 2020 (verdict: reproducible)
- Review of version 188.8.131.52 on 16th February 2020 (verdict: nonverifiable)
- Review of version 184.108.40.206 on 7th January 2020 (verdict: reproducible)
- Review of version 220.127.116.11 on 16th November 2019 (verdict: reproducible)
Help spread awareness for build reproducibility
Please follow Mycelium Bitcoin Wallet and thank them for being reproducible via their Twitter!
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.
Disclaimer: The authors of this project have contributed to Mycelium. Andreas Schildbach was so kind and independently tested and confirmed Mycelium’s verifiability here for a past version. Independent tests would be highly welcome!
Here we test if the latest version also can be verified, following the known procedure expressed in our test script:
Results: appId: com.mycelium.wallet signer: b8e59d4a60b65290efb2716319e50b94e298d7a72c76c2119eb7d8d3afac302e apkVersionName: 18.104.22.168 apkVersionCode: 3050001 apkHash: 7fcf353ca112f61ebc16f4a5ab1243ffeb012a87cca8d143fb708bdf5f8de559 Diff: Files /tmp/fromPlay_com.mycelium.wallet_3050001/apktool.yml and /tmp/fromBuild_com.mycelium.wallet_3050001/apktool.yml differ Files /tmp/fromPlay_com.mycelium.wallet_3050001/original/META-INF/CERT.RSA and /tmp/fromBuild_com.mycelium.wallet_3050001/original/META-INF/CERT.RSA differ
This diff is what we want to see to call it reproducible.
Reproducible: The provided 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.
"Reproducible" does not mean "verified". There is good reason to believe that security researchers as of today would not detect very blatant backdoors in the public source code before it gets exploited, much less if the attacker takes moderate efforts to hide it.
To understand why some lines of difference are ok and others not one has to consider how app signing works. Android supports currently 3 signing schemes and in version 1 signing the signature is put inside the application file. As the tester must not have the release signing key, those files necessarily are missing or differ from the version on Google Play. The file "apktool.yml" was never part of the app and is generated by the analysis tool "apktool".