Abstract
A method includes receiving, from a second user device, an interaction message comprising an amount and a condition, and a witness. The method also includes verifying an identify of the second user device, and the interaction message by determining that the witness satisfies the condition. Responsive to verifying the interaction message, the method includes adjusting an online balance for the second user device, generating a response message that indicates that the interaction message was successfully evaluated and the amount was added to the online balance, and transmitting the response message to the second user device.