How about this:
- When you turn up at the venue, to get "through the barrier", you have to put into a machine the card that you used with which to purchase the ticket. And you're not allowed to hand it back to someone behind the barrier. You have to put it back in the machine to come out, too.
- If someone can't attend, then they get a refund and any spare tickets go back on sale in a second wave.
If you look how the touting works, it's normally a case of people with multiple credit cards and multiple accounts, often using humans (rather than bots) to buy as many tickets as possible.
I'm sure there are problems with this method, but how many touts are going to be cool with handing over *their own credit card* to the random Swiftie who buys that particular ticket from them and only getting it back after the concert? I wouldn't, for sure! Maybe they'll cancel the cards before the gig. Trust me, after opening and closing 30 credit accounts every 2 months, the banks will stop giving them new cards. And if they've somehow used the same card to buy multiple tickets (which is supposed not to happen anyway), you either go in as a group or not at all... and stadium staff would easily spot a group of 40 completely unrelated people all going in on the same credit card (breaching the "non resale" rule and thus being refused entry).
Essentially, you're preventing the main mechanism of touting, by ensuring that the original purchaser of the ticket HAS TO attend the venue, or at least trust the attendee of their ticket with their credit card... whilst giving genuine "I can't attend" people the option of a full refund, with a second wave of ticket sales perhaps they day before the event for any that were refunded.
Note that no additional information here is collected other that what you provide ANYWAY, so people concerned about IDs and privacy need not worry! Sure, you could make it more secure by having to present [any form of] ID that matches the name on the card... but I reckon just the above might be enough to stop 90% of the touts.
Go on, rip my "great idea" apart now... please...