Beta channel

In order to receive updates quicker than others, you need to enable beta versions of the software in Google Play

As beta testers, please make sure you have a recent backup of the masterseed and all private keys inside Mycelium. Beta testers will experience many bugs. So far, restoring the wallet from masterseed has never been necessary, but we offer no guarantees.

Building

To build everything from source, simply checkout the source and build using gradle on the build system you need:

JDK 1.8

The project layout is designed to be used with a recent version of Android Studio (currently 4.1.2)

Build commands

To get the source code, type:

git clone https://github.com/mycelium-com/wallet-android.git
cd wallet-android
git submodule update --init --recursive

Linux/Mac type:

./gradlew clean test mbw::assembleProdnetRelease mbw::assembleBtctestnetRelease

Windows type:

gradlew.bat clean test mbw::assembleProdnetRelease mbw::assembleBtctestnetRelease

Voila, look into mbw/build/outputs/apk/ to see the generated apk. There are versions for both prodnet and testnet.

Alternatively you can install the latest version from the Play Store.

If you cannot access the Play store, you can obtain the apk directly from the Mycelium Bitcoin Wallet download page.

App Download Verification

All versions released by Mycelium are signed with the same release keys. If you do not trust the apk you can check that signature with apksigner:

apksigner verify --print-certs --verbose mycelium.apk

The output should look like:

Verifies
Verified using v1 scheme (JAR signing): true
Verified using v2 scheme (APK Signature Scheme v2): true
Verified using v3 scheme (APK Signature Scheme v3): false
Number of signers: 1
Signer #1 certificate DN: CN=Mycelium Developers, O=Mycelium, L=Vienna, C=AT
Signer #1 certificate SHA-256 digest: b8e59d4a60b65290efb2716319e50b94e298d7a72c76c2119eb7d8d3afac302e
Signer #1 certificate SHA-1 digest: be575ec3b3b52e0b2392146cbdb245c91ef5a04f
Signer #1 certificate MD5 digest: 7aec063675b0206aba3b6175b89abc7d
Signer #1 key algorithm: RSA
Signer #1 key size (bits): 2048
Signer #1 public key SHA-256 digest: 6d9c0cda9dcd3ec5efcdca41243829b1dcf1e9a91c6309bca167807282590a20
Signer #1 public key SHA-1 digest: b34336038c7ca678285c14aebe78b7d5add90e4c
Signer #1 public key MD5 digest: a78bdb2b6d074db4b1ff12eb9cddcfa3
WARNING: ...

Deterministic builds

To validate the Mycelium image you obtain from Google Play Store, you can rebuild the Mycelium wallet yourself using Podman and compare both images following these steps:

Get the source as above
Create your own builder image from our simple Dockerfile
```
$ podman build --no-cache --tag mycelium_builder .
```
Build using disorderfs to eliminate non-determinism caused by file ordering
```
$ podman run --rm --interactive --tty \
    --device /dev/fuse \
    --cap-add SYS_ADMIN \
    --volume .:/app \
    mycelium_builder \
    bash -c "apt update;
    apt install -y disorderfs;
    mkdir /project/
    disorderfs --sort-dirents=yes --reverse-dirents=no /app/ /project/;
    cd /project/
    ./gradlew -x lint -x test clean :mbw:assembleProdnetRelease;"
```
If you see errors about local paths not being found, remove/move away local.properties.

As container might run as a different user, its generated files will also be "not yours". Make them yours using chown as super user.

The app can now be found in mbw/build/outputs/apk/prodnet/release/mbw-prodnet-release.apk.

As maintainer with release keys you want to run a slightly different command: Add these parameters: --volume 'path/to/keys.properties':/project/keys.properties --volume 'path/to/keystore_mbwProd':/project/keystore_mbwProd --volume 'path/to/keystore_mbwTest':/project/keystore_mbwTest Build all these targets :mbw:assBtctRel :mbw:assProdRel :mbw:assBtctDeb :mbw:assProdDeb and to get an error on missing release keys, add this gradle option -PenforceReleaseSigning

Note: for those who use Docker Toolbox $(pwd) should be under your home user folder since this is the only folder that is shared with VM.

Retrieve Google Play Mycelium APK from your phone Gets package path:

  $ adb shell pm path com.mycelium.wallet
  package:/data/app/com.mycelium.wallet-1/base.apk

Retrieve file:

  $ adb pull /data/app/com.mycelium.wallet-1/base.apk mycelium-signed.apk

Extract content from both apks you want to compare, using ApkTool:

  java -jar ~/path/to/apktool.jar d mbw-prodnet-release.apk
  java -jar ~/path/to/apktool.jar d mycelium-signed.apk

Compare signed apk with unsigned locally built apk using a diff tool

  diff --brief --recursive  mbw-prodnet-release/ mycelium-signed/ | grep -v "META-INF/CERT.RSA\|META-INF/CERT.SF\|META-INF/MANIFEST.MF"

The expected difference between these files are elements that depend on the signature, that only the project's maintainer can reproduce:
- original/META-INF/CERT.RSA
- original/META-INF/CERT.SF
- original/META-INF/MANIFEST.MF

Features

With the Mycelium Bitcoin Wallet you can send and receive Bitcoins using your mobile phone.

HD enabled - manage multiple accounts and never reuse addresses (Bip32/Bip44 compatible)
Masterseed based - make one backup and be safe for ever. (Bip39)
100% control over your private keys, they never leave your device unless you export them
No block chain download - install and run in seconds
Ultra fast connection to the Bitcoin network through our super nodes
For enhanced privacy and availability you can connect to our super nodes via a tor-hidden service ( .onion address)
Watch-only addresses (single or xPub) & private key (single or xPriv) import for secure cold-storage integration
Directly spend from paper wallets (single key, xPriv or master seed)
Trezor enabled - directly spend from trezor-secured accounts.
Mycelium Entropy compatible Shamir-Secret-Shared 2-out-of-3 keys spending
Secure your wallet with a PIN
Compatible with other bitcoin services through the bitcoin: URI scheme

Please note that bitcoin is still experimental and this app comes with no warranty - while we make sure to adhere to the highest standards of software craftsmanship we can not exclude that the software contains bugs. Please make sure you have backups of your private keys and do not use this for more than you are willing to lose.

This application's source is published at https://github.com/mycelium-com/wallet We need your feedback. If you have a suggestion or a bug to report create an issue.

More features:

Sources available for review
Multiple HD accounts, private keys, external xPub or xPriv accounts
Multiple Bitcoin denominations: BTC, mBTC, bits and uBTC
View your balance in multiple fiat currencies: USD, AUD, CAD, CHF, CNY, DKK, EUR, GBP, HKD, JPY, NZD, PLN, RUB, SEK, SGD, THB, and many more
Send and receive by specifying an amount in fiat and switch between fiat and BTC while entering the amount
Address book for commonly used addresses
Transaction history with detailed information and local stored comments
Import private keys using SIPA (the ones beginning with a 5) and mini private key format (Casascius private keys) from QR-codes or clipboard
Export private-, xPub- or xPriv-keys as QR-codes, on clipboard or share with other applications
Share your bitcoin address using Twitter, Facebook, email and more.
Integrated QR-code scanner
Client side load balancing between three 100% redundant server nodes located in different data centers.
Sign Messages using your private keys (compatible with bitcoin-qt)

Authors

Credits

Thanks to all collaborators who provided us with code or helped us with integrations! Just to name a few:

Nicolas Bacca from Ledger
Sipa, Marek and others from Trezor
Jani and Aleš from Cashila
Kalle Rosenbaum, Bip120/121
David and Alex from Glidera
Wiz for helping us with KeepKey
Tom Bitton and Asa Zaidman from Simplex
(if you think you should be mentioned here, just notify us)

Thanks to Jethro for tirelessly testing the app during beta development.

Thanks to our numerous volunteer translators who provide high-quality translations in many languages. Your name should be listed here, please contact me so I know you want to be included.

Thanks to Johannes Zweng for his testing and providing pull requests for fixes.

Thanks to all beta testers to provide early feedback.