Welcome to Stamp a mobile app for signing multi sig transactions from a QR code.

Potential Uses

• Online Wallets. Stamp can be used as a safer form of 2 factor authentication.
• Online Market Places. A new wave of cryptocurrency marketplaces using multi sig transactions need an easy way for the user to sign the transaction.

How ?

Basically Stamp is a Hierarchcal deterministic Bitcoin wallet that doesn't store any Bitcoins. Rather it can issue Master Public Keys and sign P2SH transactions created with those keys.

Plan

1. Send a MPK after reading a QR code. DONE.
2. Sign a TX generated from a P2SH using the above key. IN PROGRESS
3. Fix up GUI and look and feel.
4. Test on iOS

Proposed API

Below are some example Stamp 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

To Sign a TX

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

e.g.

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

Simply take the Stamp command above and create a QR code for stamp to scan.

How do I build this ?

Stamp was written with the Appcelerator Platform http://www.appcelerator.com/. Download the IDE import the project and (hopefully) off you go.