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Posted on r/Philippines: How did the MRT's old stored value tickets work?

Haven't ridden the MRT regularly for a long while, I assume these were phased out since may Beep card na.

Specifically, where did they store value? I remember parang thin magnetic (?) card lang sya na parang wala namang chip. And if writeable sya, wouldn't that be insecure, i.e. people might figure out how to change the value of the card.

If there's some kind of centralized database, wouldn't that introduce some kind of network delay for example when the ticket is processed as you leave the station? Mabilis lang maprocess yung ticket e (otherwise, it's a problem during rush hour)

Lol sorry if it's a weird question, baka sakali lang may nakakaalam dito; I remember thinking about this when they were first introduced and I never did get an answer.

Tue, May 31, 2022, 10:29 p.m. / / notes / #philippines #reddit_submission / Syndicated: reddit / 💬 4

Last modified at: May 31, 2022, 10:30 p.m. Source file


kamanue said...

Check this website.

Basically its a magnetic stripe card, for sure walang central database yung lumang system is more on as static data and reader lang wherein the card will only read and write off the balance and read the validity date of the card.

hungryroy said...

Thanks. Although the linked article doesn't actually explain the storage mechanism. (Also grabe naman itong official gazette hindi nagrerenew ng HTTPs cert lol)

So basically you're saying writeable naman ung card (para maupdate yung balance), but in that case what prevents someone from getting the hardware to read/write magnetic stripe cards and basically reset balances? Or meron syang some sort of encryption to prevent that?

BantaySalakay21 said...

Why bother tampering with it? Magkano yung equipment to read/write the magnetic data storage of ghe card? Then ang hassle lang sa totoo yung pagsakay ng MRT lalo na kapag rush hour. Is it really worth tampering with?

hungryroy said...

IDK, I work in software, so I have to think of this sort of thing.

In theory, you only need one person with the device and he could maybe make some side money resetting tickets for other people at a low cost, etc.

You're probably right that it's not worth it though.