US Patent 7694332 Digital receipt for a transaction

A first user (110) requests a service provider (130) to create (200,400) a record of a transaction. The service provider (130) creates (230,430) a digital receipt (300,700,900), which includes a description (310,710,720,910,1020) of the transaction understandable by humans, tamper-proof evidence (320) of the transaction, and a verification prompt (330,740,940,1030). A second user (120) who desires to verify the transaction displays (265,465) the digital receipt (300,700,900) and activates (270,470) the verification prompt (330,740,940,1030). Upon activation, the tamper-proof evidence (320) is verified without requiring further human interaction to identify the tamper-proof evidence.