RFID question

I have been playing with an RFID reader (YHY502CTG) with an idea to using it for a keyless entry. It runs at 13.56 MHZ and supports ISO1443A/MIFARE. So far so good, but I am curious. When you bring a card near it, an led lights showing it senses a card. I know some credit cards also have a 13.56 chip in them. When I tried to see if it would light the led, it didn't. Anyone know what the difference is or do I just have a bad chip in the card? I have never used it, so I don't know if it works. Again, I wanted to see if my entry system could be activated by a random RFID card, but I was figuring it would be the embedded code and not something physical. Any info would be appreciated.
DocBill

I know some credit cards also have a 13.56 chip in them.

No most credit cards do not have a contactless chip in them.

When you bring a card near it, an led lights showing it senses a card.

Not quite that is showing that it has read the public ID of the card.

When I tried to see if it would light the led, it didn't

I would not expect it to.

Again, I wanted to see if my entry system could be activated by a random RFID card,

No the MIFARE cards have unique IDs on every one. Your system has to look at the number the reader returns not just the fact that the reader sees a MIFARE card.

No most credit cards do not have a contactless chip in them.

Actually many do. On closer inspection I have 2. They can be identified by a WiFi-like logo on the card. Mastercards call it paypass or blink. If the cards have a public ID, why wouldn't the card be detected?

No the MIFARE cards have unique IDs on every one. Your system has to look at the number the reader returns not just the fact that the reader sees a MIFARE card.

I do check the ID's. I just wanted to see how susceptible the system was to being cracked. The curiosity about the credit card was just a by-product.

wmassano:
Actually many do. On closer inspection I have 2. They can be identified by a WiFi-like logo on the card. Mastercards call it paypass or blink. If the cards have a public ID, why wouldn't the card be detected?

It could be that its not a 13.56 Mhz chip on that card. If it is a 13.56Mhz chip, then maybe the IC on your reader isnt equipped to handle reading the credit card RFID.

Actually many do. On closer inspection I have 2. They can be identified by a WiFi-like logo on the card. Mastercards call it paypass or blink. If the cards have a public ID, why wouldn't the card be detected?

Well I don't know where in the world you are but I have never seen one in the UK.
Like the previous poster said Wi-Fi is not RFID. Also there are many standards of 13.56 MHz chips and they are not all interoperable.
As to being cracked, yes you can do it but it is more in the realms of films than real life. Remember an old proverb is :- a lock only stops an honest man

To UNTengineer: Could be, but all the info I have seen says it's 13.56. Like I said, it was just curiosity.

To Grumpy_Mike: USA and they are fairly common here. Many retail stores have a blink terminal. I believe they are good for under $25 purchases. I never use them, but some of my cards have the chip. There was a report on TV some weeks ago about how some guy bought a reader on ebay (about $70) hooked it up to his laptop and was getting credit card info. In fact, with the owner's permission, he used the info obtained from bumping (to get closer enough to read the card in his pocket) his target to clone a card onto a hotel room keycard and then used the card to charge several hundred dollars from retail stores. No one even questioned that it was a room key. Scary!