The OnChain.IO wallet. A simple user interface hiding a HD wallet with some advanced features.

Wallet	BIP 39	BitID

Notes

• Wallet functionality coming soon. i.e. spend and receive via QR code.
• The onchain.io app can be used as a safer form of 2 factor authentication. It is used by the https://www.onchain.io online wallet to split keys across devices.
• The onchain.io protocol for transaction signing has been implemented in the bitwasp project as a multi sig marketplace.
• The landing page for the android app is here Android Bitcoin Wallet

How ?

Basically the onchain.io is a Hierarchcal deterministic Bitcoin wallet.It can issue Master Public Keys and sign P2SH transactions created with those keys.

API

Below are some example commands.

Get a Master Public Key

mpk|service-name|Callback URL (POST)|Pipe seperated paramers you supply

e.g.

mpk|mywallet.com|hxxp://mywallet.com/external_mpk|user|980190962

Get a Public Key

pubkey|service-name|Callback URL (POST)|Pipe seperated paramers you supply

e.g.

pubkey|mywallet.com|hxxp://mywallet.com/public_key|user|980190963

To Sign a TX

sign|service-name|Callback URL (GET and POST) to get the TX|Pipe seperated paramers you supply

e.g.

sign|mywallet.com|hxxp://mywallet.com/sign_tx|user|980190962

For TX signing, your call back URL will be called twice. Once with a GET operation to get the existing TX. Seconds with a POST operation to send the signed TX back to your service.

Simply take the command above and create a QR code for the onchain.io app to scan.

Setting the wallet seed.

The first time it's run the onchain app will generate a BIP32 wallet seed. To backup the seed click on the menu and select "Show BIP39 Seed"

To set a seed generate a QR code containing a 24 word BIP39 compatible passphrase. Scan the passphrase in with the onchain app.

How do I build this ?

Built with Android Studio.