Systems and methods for allowing separate parties to identify each other through the use of matching computer-coordinated identifiers are discussed. In some cases, the methods include using a processor of a computer system to identify a first computer device configured to provide a first perceptible identifier, using the processor to identify a second computer device that is configured to provide a second perceptible identifier, and using the processor to send the first perceptible identifier to the first computer device and the second perceptible identifier to the second computer device, wherein the first and second perceptible identifiers correspond with each other to provide a two-sided, computer-coordinated verification. In some cases, the described methods include modifying the first and second identifiers as the first and second computer devices come into proximity with each other. Other implementations are discussed.