I found some boom barriers,used for gate system, were integrated with UHF reader + access controller and a UHF stickers (attached in car's windshield) for access control using wiegand protocol.

In my review of UHF tags, its memory can be write protected but not read protected because any UHF reader can still read it, right? Therefore it is easy to clone. So how can we make this gate system with passive uhf tag be more secure from someone who wants to trespass?

Or in general, can we make a readable object, from any state, more secure?

2 Answers 2


can we make a readable object, from any state, more secure?

You need an RFID tag that uses a challenge-response protocol. The reader would send a challenge key and the card must return a cryptographic signature of the challenge key, without ever exposing the secret signing key itself in the transmission. The card should then be designed with physical tamper resistance to make it difficult, if not impossible, to extract the key from the card without damaging the card.

  • Check that the challenge-response protocol is actually secure, too. Mifare Classic is pretty much completely broken, for example. Jan 28, 2018 at 7:06

The 'quick fix' approach would be to use a Gen2 IC that has a unique serial number in the TID memory. This serial number is pre-programmed during the production of the IC, and is guaranteed to be unique. Most modern ICs support this functionality, and it is not easily cloned.

  • One can buy tags on ebay with writeable serial numbers. Jan 28, 2018 at 7:05
  • There is a difference between serial (part of EPC memory) and TID; the TID is never writeable - or you should develop your own ICs. That might eventually happen, but is currently not the case.
    – Danny
    Jan 29, 2018 at 7:31
  • I'm not familiar with Gen2 tags, but MiFare claimed the same and there are now clones available with writable unique IDs on ebay. At the very least, expect that they will be cloneable some day. I've found offhand references to cloning a Gen2 TID, but nothing solid. Jan 30, 2018 at 5:46

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