Writing on Mifare classic 1K card.

[aitor]

Dear all,

I work with some terminals where the customers have to show the Mifare 1K card and some information is written on it. Occasionally the information written on the card is deleted and 0x00 is written in the whole bloque.


Some clients tend to remove the card before the writing is completed, but I don´t understand why are the cards written with zeros.

Can somebody help me?
Thank you in advance.

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[mifaresdk]

Hi,

I am not sure what happen in your case for this issue. But you should take in mind that a user may remove the card from the antenna area before all operations are complete. This is called “tearing” and you should look at features of “anti-tearing”.

The MIFARE Classic does not support anti-tearing by hardware, but you can implement it in software. You define two sets for the data you want to write. One is the backup of the other. If you could write two times and both were successfully, then the content is accepted. Otherwise you know the previously write operation was interrupted and you use the backup value and back off the other one.

Kind regards,
The MIFARE Team

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