How Do I Book a Seat at the Edinburgh Festival Without Giving You My Name, Address, and Any Other Detail?
Well it’s that time of the year again, where Edinburgh is bursting at the seams. But you are worried about all the data breaches that are happening. So how can we generate a receipt of the booking, but not give away your identity, or the details of the booking? Let’s take an example of booking a seat in a theatre at the Edinburgh Festival, and how your privacy can be respected, but where the theatre will trust the ticket.
Booking a ticket
Let’s say there are 100 seats in a theatre, and I want to book one of them, but I don’t want the theatre company to know which seat I’ve booked, or my identity. I also want a receipt of purchase that they can verify my booking. One way would be to get a trusted agent to look after the bookings, but I don’t trust them either. So how can we do this?
Well it can be done with commutative encryption.
The steps would be:
- Initially the theatre company generates 100 receipts for each of the seats, and then encrypts them with its public key.
- Next when I want to make a booking they send me the encrypted receipts that they have left, and I select one at random, and then encrypt it with my public key.
