I'm wondering if NFC chips have some kind of unique identifier? I have Mifare Classic 1K and Mifare Ultralight C stickers that I want NFC phones to read using my android application, is there some common practice to protect the signal so someone can't just come in and scan the data using a generic app (NFC Reader), and write the data to another chip in order to fake my sticker signal. Or, is there a unique ID like how phone UUID works built in these chips?
I'm afraid with tags there is always the risk of evesdropping, man-in-the-middle or relay attacks. The best you could hope for would be encrypt the data using a pre-known secret on your device and the tag.
This still has the risk of the secret being found out and then copied.
NFC really isn't designed to be a highly secure platform.
For device to device you can implement protocols on TOP of the existing NFC stack (such as SSL) however this wouldn't work with pre-generated tags.
Yes each chip has an unique identifier, however the comments from the other people here about lack of security are of concern as this is the currently (growing) preferred hardware platform of choice for financial transactions of the future.
Cloning is a greater challenge than just sucking the data off one chip and replicating it on another.
What specific usage did you envisage for your 'highly secure' Android application?
You have MIFARE Ultralight C tags. These tags have functionality that allows one to protect access to data stored on the tag to be protected by 3DES-based authentication. That would prevent unauthorized read access.
In general, I would recommend against using the tag's unique ID as a security feature.
Related
I was wondering if it is possible to code on a NFC whatever we would code with Javacard ? I have a project where a smart card contains a biometric id to be scaned and and we want to do it wirelessly with a NFC. Do you think that is possible ? What are the boundaries of NFC ? Is it possible to do whatever we do with Javacard on NFC ? Sorry I have a lot of questions I'm not very familiar with the topic.
Yes it is possible for some Javacard's to be interacted with via NFC.
See https://github.com/OpenJavaCard/openjavacard-ndef as an example.
The answer is yes - many contactless and dual-interface cards are in fact running JavaCard applications. When you go to the higher protocol layers, the commands (APDUs) exchanged using NFC are basically the sames as using the contact interface.
In essence, NFC is a communication channel, while Javacard describes a programming framework (requiring a processor card with a certain processing power). Of course those two can be combined.
NFC is also used as term for rather dumb tags, which may provide some hardwired cryptography (as DESFire does) but not much beyond that except data storage space. There is no way, on which such a tag can process even the most basic "hello world" applet, and mastering the same communication technology does not not help much in that respect. Computing a digital signature can be considered as litmus test, what you really have.
I'm trying to implement the functionality for emulating a Mifare One (1K/S50, ISO14443A) chip to be able to use a phone with NFC capability instead of a physical Mifare card or, if possible sending only the data to the reader.
I have this type of reader/writer: https://www.evelta.com/er302-high-frequency-nfc-writer-usb/
After looking around on forums, stackoverflow questions I found this article to be the best example:
https://medium.com/the-almanac/how-to-build-a-simple-smart-card-emulator-reader-for-android-7975fae4040f
I implemented the HCE part, run the program, and the reader beleives my phone is a Mifare chip, so far so good.
My problems:
No matter what "standard" Authentication key I tried to use...it gives me Auth error. I read this question about Auth: Authentication failure for Mifare 1K NFC tag using ACR122U NFC reader, it works on a physical Mifare card...but I don't know how to set or get to know the keys for the emulated one.
I don't get why this example emulates that exact Mifare chip type...even breakpoints don't work in the APDUService, but the reader detecting a Mifare cheap somehow.
After reading about it, I get I can't 100% emulate a physical card, so I have to send all the data I want in my APDU response with the service somehow (I beleive it's the transreceive part).
However I can't even authenticate.
I tried to look for other possible solutions:
AndroidBeam: Android - Android p2p...sounds simple, relatively high-level API, but it's being deprecated, moreover it's not guaranted that the reader will even use Android...it might be a 'simple' USB reader hardware like the one I use.
SecureElement: Ironically...it seems to be the most recommended, I read that 'yes, it's possible for mifare' and things like that, yet I couldn't find a good example of it and the official Google docs don't have any good example. I read that it's for "ISO/IEC 7816-4", but Mifare 1K is ISO14443A, so I'm a bit sceptic about this API.
"Simply" sending the data to the reader: If I could just simply "push" the data out to the reader when it's reading the phone without complicating the matter or emulating anything...it would be great but I don't know if it's even possible. This whole NFC topic seems to be more and more complex.
So alltogether I only need to do one thing: taking the data and send it to the reader.
I realized it's a fairy tale like illusion to beleive it's as simple as it sounds, still, I hope there is a way to do it.
If I could send the data in it's own, without emulating Mifare or anything...after all what matters is that the data on the card, not the type of the chip, the more simple the solution will be, the better.
Sorry for possible English grammar mistakes.
The problem is you cannot use HCE on Android to emulate a Mifare Classic 1K (https://www.nxp.com/docs/en/data-sheet/MF1S50YYX_V1.pdf) as this is a custom Type NFC card. As HCE is about emulating Type 4 cards. See https://developer.android.com/guide/topics/connectivity/nfc/hce#SupportedProtocols
And the below image helps understand the type.
You can see this from it's datasheet, nowhere does it talk about AID's and standard Type 4 NFC commands
Though Type 2 and Type 4 can share the Anti Collision mechanism and Reading the UID (which is part of the process) any other access methods are not shared.
Type 4 Spec for reference is at http://apps4android.org/nfc-specifications/NFCForum-TS-Type-4-Tag_2.0.pdf
I have seen some USB readers that offer on reader emulation of other card types but not HCE where the host does the emulation not the NFC hardware.
The Authentication on Type 4 Cards or emulated ones is handled differently.
You can emulate a MIFARE DESFire Card as that is a Type 4 card.
The specs of your card reader are not documented well and it looks very "lite" and that it does not support any of the higher level protocols needed to talk to non Mifare Classic cards. It could support them but as Mifare protocol was the original spec, it could be possible for it to be and old design and only support the Mifare protocol.
I am extremely new to NFC as a technology and have a very basic question. I am investigating the use of NFC tags in the field of authentication. At a broader level imagine a PKI architecture. A private key resides on the NFC tag, and an app can access it for authentication/signing/validation etc.
I understand that smart cards are the de-facto standards for such things, but the cost of NFC tags is far far less. My question is what level of protection is offered by NFC tags for such a scenario or is NFC tag a good choice for such a design?
Can I somehow ensure that a tag is readable by only a certain device? As in, can another user just use his phone/NFC reader to read the key on the tag? What methods are available to protect/restrict access to the data residing on the NFC tag?
There is nothing inherent in an NFC tag that restricts access to read the data to one device. For the most part everyone can read, and everyone can write if the tag has not been made read-only. Some of the newer NTAG series of chips have password features allowing only software with the password to write the tag.
All NFC tags come with a unique manufacturer supplied id that is often uses in security implementations. It is very difficult, but not impossible to clone that ID. It is very easy to close the data on an NFC tag. There are a new set of "secure" tags being developed, but these often have a server-side component. One thing to note, is that while the data on the tag can be read by anyone, that says nothing about what value they actually get.
Many people encrypt the data and store the encrypted value on the NFC tag. The decryption key is then known by the software and can then read and interpret the tag's data. This requires custom software as its not a part of the current NDEF spec. This is really the same as SSL, where someone can sniff the network traffic but not know what the actual data is. In general we advise customers to make the NFC tags as "dumb" as possible and leverage NDEF for the broadest compatibility without custom software.
DISCLAIMER: I am the CEO of GoToTags, an NFC software and tag solutions provider.
NFC tags are basically a data store. They may provide restrictions for accessing data, but they remain a data store. If you implement a PKI with a NFC tag, you only store keys on the tag, no computation is done on tag.
On the other hand, PKI smart cards store the keys, but they also provide the computing resources for calculations done with the keys. Moreover, they are designed in a way keys never leave the card (on demand or by side-channel attacks). This way, you may expect key not to leak.
Because they offer different services, NFC and PKI card interfaces complexities are not the same at all.
Note some PKI smart cards do offer a contactless interface. This is not NFC tag interface, but rather PKCS#15 over ISO14443-4.
I'm new to the NFC standards and I have only played with Ntag203, Mifare Classic and Desfire. I'm trying to figure out what is the advantage of Desfire for our application.
I have looked through ISO 14443 and ISO 7816-4 standards and I can only figure out that the Desfire provides a standards compliant API to manage encryption to ensure interoperability between OEM client applications, readers and cards.
Let's say I am building a mobile client that needs to encrypt and store data using the same scheme as Desfire (AES or 3DES) - can I do that completely client side with , say ntag203, and not violate any security standards.
I have worked with PCI-DSS and am worried if this is some kind of mandatory technology to be able to process sensitive data like health records, payment balance, etc
For my master thesis I'm investigating the possibility to use an NFC enabled phone for opening off-line door locks. These locks currently work with DESFire cards which contains authorisation data. Furthermore, the card is also used to update configurations and obtain maintenance messages to/from the lock. The goal is to update and read this information to/from the lock via an application on the phone that communicates with an external server over the internet ultimately making the exchange of this information more efficient.
Currently, I think the best choice for getting card emulation to work is to use an SD card with NFC and a secure element. This provides two possibilities:
1) A possibility is to implement a custom made java card applet that emulates a DESFire card. Theoretically, this should be feasible as DESFire cards optionally supports APDUs (ISO7816).
2) Some of the NFC SD cards available on the market offer DESFire emulation as a ROM.
I've the following questions:
For option 1 I wonder what will happen if the off-line lock / reader initiates communication using DESFire 'native' commands instead of APDUs. Is it possible to interpret non-APDU commands from java card? If not, it probably means it will not work?
Is it possible to manage the content of an emulated DESFire card in option 2? The NFC SD cards that I saw provides a proprietary API to access the secure element. It allows this by transceiving APDUs. The emulated DESFire, however, is not a java card applet in this case but it is a ROM which may or may not support this communication with APDUs.
I know this question is not strictly related to programming. But I found that there are quite some people on stackoverflow with expertise on NFC related topics. In fact, I found most of my information here.
Thanks
In order to answer 1 you would need to examine carefully ETSI 102 705 and see if the API lets you process CLT events (lower level protocol exchanges) instead of the contactless chip. I think this is unlikely.
In option 2 there surely is a way to manage the contents, otherwise the proposed desfire emulation would be totally worthless, but this might end up being partly proprietary, or requiring a substantial effort in cryptography, in which case you need to obtain the right keys.
All in all, if I were you, I would do ISO7816 (14443-4) card emulation using javacard, and forget about all the NXP proprietary stuff, which is built to make you buy licenses and associated software solutions.