> Every Suica card has a chip storing two things: a unique card ID, and your current balance. Both of those live on the card itself, rather than a central serve

> Every Suica card has a chip storing two things: a unique card ID, and your current balance. Both of those live on the card itself, rather than a central server. When you remove the network and run locally, you’d expect it to be amazingly fast. But it’s also effectively physical cash. And that has many downsides as well.