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I know NFC is the new in thing and it may go a long way specially w/ payment systems.

I'm new to this wireless tags thing.

I'm a PHP applications developer and I'm gona do a few applications like Daily Time Recording and Membership app for an establishment.. My requirements are simple.. rather relying on barcode on ID's , or magnetic strips, I wanted to employ RFID, or perhaps NFC for this system.

All I need at the moment is the secure ID of the tag to be combined w/ an entry / profile in MySQL and do my magic from PHP side. I don't need long range reading /writing capabilities like RFID.

Would like to know the following:

1) W/c is generally cheaper to implement? Cheaper readers? Cheaper tags?

2) Which is more secure based on the above? I was told NFC is more secure, but w/ people being able to read and write on tags using their phones, how secure is it really? I do not plan to store vital info on the NFC chip, or if I do ill probably use some encryption to jarble the text data 3) NFC tags can be set as READ ONLY.. how does that work? is that secure? reliable? 4) Is it easier to mimic the tag's id/serial vs rfid serial?

and lastly, not to ask you guys to shop for me, but more on to point me to the right direction.. is there a reader/writer that has API's built in so that i can interface w/ it immediately using PHP?

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  • \$\begingroup\$ RFID is a one way system, NFC allows two way communications (effectively an intercom). It looks like all you need is an RFID system. How easy are they to spoof? instructables.com/id/RFID-8 \$\endgroup\$ – JIm Dearden Jul 3 '13 at 11:01
  • \$\begingroup\$ thanks but yes, what is cheaper though? i mean from first impressions NFC seems to be cheaper over all.. specially on the per chip costs plus allowing 2 way com when needed. is this accurate assumption?? \$\endgroup\$ – BrownChiLD Jul 4 '13 at 4:12
  • \$\begingroup\$ Consider that the chip cost is not the only factor. With RFID you'll issue a card/tag that is already mass produced, and has to develop only the other end. With NFC you have to do both (or let the person use a cellphone, which also isn't cheap). That means developing and manufacturing PCB, case, etc. Not to mention FCC (or equivalent) certifications. \$\endgroup\$ – fceconel Jul 4 '13 at 17:41
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RFID certainly is cheaper and simpler.

The main difference between the two is that with RFID the person carries a card/tag/etc. that can be thought as "passive". It is only powered when near (and by) the receiving antenna. NFC is to be embedded in cellphones and uses its source of power (the battery).

RFID is pretty secure for most applications. It is widely used around the world for bus fares. Only when you have applications that require more security (credit/debit card transactions, for instance, in which the average transaction amount is significantly higher) it wouldn't be recommended. Thus enters NFC.

For a test/demo environment, I'd recommend you to visit SparkFun or Adafruit. Their products are aimed at the hobby market, so they are pretty easy to start using. In general they'll open a virtual serial port via USB, so what you'll need in PHP is just any standard library for sending/receiving data through a serial port.

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  • \$\begingroup\$ FCeconel, thanks man .. that was helpful. About the NFC though, when comparing the "tags", arent NFC just about the same price and power-less as well? Is there any proposed designs to make long range powered NFC tags? \$\endgroup\$ – BrownChiLD Jul 5 '13 at 4:02
  • \$\begingroup\$ NFC may or may not be powerless, but if it is, then will be essentially equal to RFID. To take advantage of two way communication you need some "intelligence" in the device - a cellphone or a microcontroller - whose are very difficult, if not impossible, to make work without a local source of power. \$\endgroup\$ – fceconel Jul 5 '13 at 17:59
  • \$\begingroup\$ Also notice that the increased security when using NFC is not given by NFC itself (its protocol is not much different from RFID) but by such cellphone or microcontroller when they implement some cryptographic authentication. \$\endgroup\$ – fceconel Jul 5 '13 at 18:06
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    \$\begingroup\$ RFID has the advantage that many people already have a tag, so instead of issuing yet another tag/key/card, you can just let the user put their card on the reader, and you associate the number with the user. Heck, back in highschool they let you use your bankcard or whatever magstripe-card you wanted for access. \$\endgroup\$ – Lenne Jun 30 '16 at 11:04
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    \$\begingroup\$ My retrofitted car immobilizer uses RFID. I can program the immobilizer to use the RFID-chip in my cat; I tried it before the cat got it injected though. ;-) \$\endgroup\$ – Lenne Jun 30 '16 at 11:08
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2) Depending on which NFC tag you use, it will have built in encryption. If security is something you require have a look at MiFARE DESFire and MiFARE UltraLight. The tag is split into sectors of 64 Bytes. Each sector has its own access keys (think of these as passwords).

3) You set the read-only bit for a sector, and the tag blocks any write requests to that sector.

4) Normal tags cannot have their serial (UUID) changed. This information is stored in sector 0 of the tag. Normally sector 0 is locked at the factory, although "magic chinese" cards exist with this sector unlocked and therefore UUID changeable. Also, it is worth noting that MiFARE classic UUIDs are not entirely unique. NXP used all the UUIDs, so they are cycling through them all. Chances are that you won't have 2 tags with the same UUID, but don't depend on chance for critical applications.

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