> the London Oyster is a Mifare Desfire EV1 There are two distinct types of Oyster card, but I don't know which is which, other than from a user perspective. A

> the London Oyster is a Mifare Desfire EV1 There are two distinct types of Oyster card, but I don't know which is which, other than from a user perspective. All I know is that I had an old style one (the one without the white D in a blue square on the back) and you could still use it, you just couldn't "connect it" to the app so you couldn't look up your travel history. There was a complicated process for returning it and getting a replacement, but as they'd already phased in paying by bank card by then, and the only advantage of an oyster card was for season tickets, I just returned it and got my deposit back. But if you're into collecting different card types, you might want to try to get hold of one of these old ones as well. They're probably somewhat rare now, as they were encouraging people to upgrade to the new ones at least 5 years ago.