In one embodiment, a unique (or quasi unique) identifier can be received by an application store, or other on-line store, and the store can create a signed receipt that includes data desired from the unique identifier. This signed receipt is then transmitted to a device that is running the application obtained from the on-line store and the device can verify the receipt by deriving the unique (or quasi-unique) identifier from the signed receipt and comparing the derived identifier with the device identifier stored on the device, or the vendor identifier assigned to the application vendor.