A ticket is valid if and only if it gets you into the concert. You can ask the concert organizers to validate tickets for you. Most concert organizers have conc

A ticket is valid if and only if it gets you into the concert. You can ask the concert organizers to validate tickets for you. Most concert organizers have concentrated on two sites that allow them to validate tickets. That is why Ticketmaster is valuable, despite its terrible reputation. A cryptographically signed I owe you is and will always be meaningless. What is meaningful is the signature at the end of the chain, when the concert organizer lets you in.