Recently, the appearance of public NFC tags are growing in major populated areas. The company I am currently working along side with wants to increase their advertisements with a NFC tag placed on the side of their ad so users can navigate to their website and,want to later expand it to opening up the app store to download a specialised application.

How would one go about protecting the tags at that point? As these tags are available to purchase to the public and do not take two wits to program something simple & someone who specialises in programming can figure out a simple malicious hijack (there's a few which come to my head, for security sake I will not name)

So with the scenario that unattended public NFC tags, how to prevent malicious hijacking ie. Prevent person A from swapping out legit nfc tag with a malicious tag in its place?

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    On a similar note, how do you prevent someone from pasting a sticker of a QR code to a malicious URL over your legit QR code? Nov 27, 2014 at 7:12
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    Do you know people who are willing to waste their time scanning some NFC tag (or QR code) just to see even more advertising/commercial content ? I don't know any, and if no one cares about these tags then the attackers won't waste their time either (what's the point if no one will ever visit their malicious link).
    – user42178
    Nov 27, 2014 at 12:11

1 Answer 1


The two problems you are facing with NFC tags is either preventing a re-write of the tag by a malicious user, or the NFC tag being replaced by a malicious one in the advertisement.

The first problem can be resolved by using read-only NFC tags. These cannot be reprogrammed and thus thwart any attempts to modify the NFC tag contents.

The second issue is a bit harder to prevent and depends on the physical security of the advertisement. Embedding the NFC tag in such a way that it cannot be removed or, when removed, would invalidate the advertisement is one way to go. This is however specific to what that advertisement would look like. I would imagine if it's just a piece of paper, the NFC tag should be embedded in that piece of paper in such a way that if removed, the advertisement would have to be torn apart or something to that accord.

  • But then again, I could just 'paste' another NFC chip over it
    – Michael
    Nov 27, 2014 at 12:39
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    @Michael, also true. I suppose the advertisement could contain a warning that any attachments to it are not part of it and the advertisement should be discarded should there be any.
    – mart1n
    Nov 27, 2014 at 14:53

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