[3ndL3ss]

hey all

i want to talk about rfid , about this kind of tags HERE --- cloth tags ,

can we really rewrite the data of this tags to bypass the security alarme ??
for ex : read data of this tag using android apps like ( NFC Tools ) then rewrite it !
can some one here talk about this idea, because i never seen befor a subject talking about colths rfid :p !

[Pikami]

Yes it is possible... well there is a catch tho.
Different cards act in different ways, some cards just give all the information they have that is easy to clone because you just have to replicate the information sent.
There are cards that are more secure that just give some public info and keep the private info private here's how it works:
1. NFC tag sends it's UID to the reader
2. Reader sends an authentication block to the tag
3. Tag picks a random number and sends it to the reader
3. The reader picks a new random number, "A shit load of math happens" using the block and the random number from the tag on the reader and then it sends the new block to the nfc card
4. The tag decrypts the block and gets the reader's random number
5. The tag now uses it's random number, reader's random number, UID, encrypts the Secret key and sends it.
And that's basically how Mifare cards work.
So in the case I described you could clone the card because the Mifare cards use 48 bit keys so it would take like 10h to brute-force

Okay so the thing is, it depends on the cards and implementation.

[Synthx]

This sounds very interesting to me, I want to keep up with this thread and see what everyone has to say. Thanks for sparking the topic.

[3ndL3ss]

Yes it is possible... well  there is a catch tho.
Different cards act in different ways, some cards just give all the information they have that is easy to clone because you just have to replicate the information sent.
There are cards that are more secure that just give some public info and keep the private info private here's how it works:
1. NFC tag sends it's UID to the reader
2. Reader sends an authentication block to the tag
3. Tag picks a random number and sends it to the reader
3. The reader picks a new random number, "A shit load of math happens" using the block and the random number from the tag on the reader and then it sends the new block to the nfc card
4. The tag decrypts the block and gets the reader's random number
5. The tag now uses it's random number, reader's random number, UID, encrypts the Secret key and sends it.
And that's basically how Mifare cards work.
So in the case I described you could clone the card because the Mifare cards use 48 bit keys so it would take like 10h to brute-force

Okay so the thing is, it depends on the cards and implementation.

you think that there is a some shit protection like Mifare cards !?? ( well i don't know )
as u can see here our RFID tag have these features:
Protocol: EPC C1G2 (ISO18000-6C) --- not important
Frequency: 860-960MHz --- i don't know if our reader can catch this frequency by default // or enter this frequency manually to read/write
EPC memory: 96bits,maximum 480bits
User memory: 512bits
Read range: 2-4M --- same here don't know what's this :/ !
EAS function: AM+RFID or RF+RFID
Detection area: ＞1M(one antenna system)
Re-write: 100,000 times

can someone tell us more !
thanks