share-public-addresses.md

Share public address

Motivation

In order for a user to receive MobileCoin transactions, they must share their PublicAddress with a sender. The sender can save this PublicAddress for future transactions. A user's PublicAddress is not considered secret and does not expose any information about the corresponding account information, past/future transactions, or balances.

Users can share their public addresses without sending a transaction. Public addresses can be exchanged prior to any transactions taking place and saved as part of a contact or contact-like data structure. This could allow for reconstruction of transaction history between known contacts using Recoverable Transaction History (RTH).

Implementation

Using the MobileCoin Android SDK, a user's PublicAddress can be obtained using the following code:

PublicAddress pubAddress = accountKey.getPublicAddress();

To generate the printable String that can be shared with another user, the following code can be used:

PrintableWrapper wrapper = PrintableWrapper.fromPublicAddress(pubAddress);
String printablePubAddress = wrapper.toB58String();

This String can then be shared with a potential sender using any suitable method (Copied text, QR code, etc.). Subsequently, a sender may recover the PublicAddress using this example code:

PrintableWrapper wrapper = PrintableWrapper.fromB58String(printablePubAddress);

if(wrapper.hasPublicAddress()) {
    PublicAddress pubAddress = wrapper.getPublicAddress();
        ...
}
else {
    // notify user of invalid PublicAddress
}