Reader-added tags include "Keikyū : 'I don't get it'," "Suika survey", and "PiTaPa : 'I don't get it'."

We'll give you a pass on the survey this time:

Which card do you use?
• Kitaca
• Manaca
• ICOCA
• Sugoca
• Suica

The card is very handy in Taipei. The only problem is, it's ONLY used in Taipei.

myman88 said:

The card is very handy in Taipei. The only problem is, it's ONLY used in Taipei.

Aren't most cities' Suica analogues only usable in their home cities/metropolitan areas? I don't expect to be able to use an Oyster card in the Paris Metro or a Metrocard on the Chicago El. (unless it's a national-level Suica, in which case it should be usable throughout its home country)

Are balances stored on the card itself or in a central database that the readers access?

BadRoad said:

Are balances stored on the card itself or in a central database that the readers access?

My (somewhat educated) guess banks on the cards only holding an identifier. Most such cards work via RFID, with the reader sending radio waves and the card resonating back a specific message, basically the card's unique identifier. This makes them very simple to construct, and resistant to any potential hacking (someone could simply copy a card with high balance on it, without tampering with the contents, and engineering any countermeasures to that is a tall order).

Suica uses a central server and ID stored on the card; I think this is the case with all FeliCa architecture cards. (More about Suica at Japan Railway & Transport Review .)

Suica and a number of other nominally regional IC cards (in the red box, plus PiTaPa, which is a little odd) are for most purposes interchangeable, meaning that a PASMO/ICOCA/etc. will work in multiple different urban areas regardless of where it was issued. They don't have universal coverage throughout the entire country, though, as the shinkansen and many smaller (usually rural) lines and bus operators don't take them.