How to Copy or Clone Access Cards and Key Fobs Step by Step?

In this post, you’ll learn:

  • How many RFID cards exist
  • The best ways to copy your office 125khz access cards with step-by-step instructions in LESS than 1 minute (including the tools you need)
  • Another step-by-step guide on how the more advanced 13.56MHz cards can be copied (and, of course, which equipment you need)

You’ll learn to clone cards (NFC or RFID cloner) at your office desk!

The Impact of RFID Cards and RFID Key Fobs

IDTechEx found that in 2015, the total RFID market was worth $10.1 billion. The parent directory for NFC was estimated at $10.1 billion — from $9.5 billion in 2014 to $8.8 billion in 2013.

This market sizing includes all the tags, readers, and software designed for RFID cards and key fobs, including all form factors. IDTechEx states that the market will rise to $13.2 billion by 2020. The security industry has experienced a significant overhaul with advances in technology.

For example, door security has evolved from simple padlocks and keys to RFID-enabled cards and fobs that can be swiped and triggered, as well as electric locks to open doors.

While this technology is impressive, it requires constant evolution and adaptation to defend against malicious users.

Any new technology, from the moment it is introduced to the general public, is vulnerable to manipulation and hacking by malicious users. An excellent example of this is RFID tags in 2013.

At the time, RFID technology had spread like wildfire across many sectors — tech companies, hospitals, and more were using 125-z cards to access doors secured with electric locks.

Most were using the EM4100 protocol card (125khz card) or a CMOS IC-based card, which had the information about the tag or fob stored openly. Since these ICs had no encryption or authentication, they would broadcast their information as soon as a reader was nearby.

This posed a huge security risk to companies dealing with sensitive information and products.

Essentially, anyone with the right equipment could steal or replicate these cards and fobs, whether authorized or not.

What RFID card can be copied?

RFID cards work on different frequencies and encoding standards; not all are equally easy or possible to copy. Generally, the most commonly copied RFID card types include:

  • 125kHz RFID EM4100 card: These are low-frequency and generally easier to clone. You would need an appropriate reader/writer and blank cards of the same frequency.
  • HID Proximity Cards: These are commonly used for building access and are relatively easy to clone with the right equipment.
  • Mifare NFC Classic 1K RFID cards were once very secure, but vulnerabilities have been discovered that make it possible to clone with the right tools and knowledge. They operate at 13.56MHz and use NFC (Near Field Communication) technology. To clone these cards, you would need a device capable of reading and writing NFC data, such as an NFC-enabled smartphone or a specialized device like the Proxmark3.
  • 13.56MHz cards: These are high-frequency cards, including several types, such as MIFARE Classic, MIFARE DESFire, or HID iCLASS. The ability to clone these depends on the specific card type and its security features.

However, cloning or copying an RFID card might violate privacy laws and terms of service, potentially leading to legal consequences.

How can they be copied?

Previous posts on our blog explore how HID cards can be hacked and how the Wiegand protocol, used by HID readers, can be copied by HID card cloners. This post doesn’t go into as much technical depth but should be a fast and easy way to understand the card copying component.

How to Copy 125khz Cards? — the Old Way:

Like the one seen here, a reader can easily copy the ID of an existing 125khz EM4100 or a similar protocol chip and copy it to another card or fob.

One of the first people to attack this security standard in 2013 was Francis Brown—managing partner at the security firm Bishop Fox. Brown set out to test the security of the standard deliberately and developed an Arduino-powered reader/writer that could copy existing 125khz tags and fobs.

It’s been five years since Brown developed his tool to hack into these systems, and plenty of companies have switched to a more secure, higher frequency standard.

However, many businesses have not updated and used the 125khz EM4100 cards and fobs, making them vulnerable to attacks.

How to copy 125khz cards with an RFID copier?

The “Handheld RFID Writer” (buy one here for as little as $11) works like this:

  • Turn on the device, hold a compatible EM4100 card or fob to the side facing the hand grip, and click the “Read” button.
  • The device will then beep if it succeeds, replace the copied tag with an empty one, and press “Write.”
  • The information stored on the original tag or fob will then be copied onto the new device

Done! Don’t believe how easy it is? Here’s a video to show you:

That’s how easy it is to copy or clone an access card or RFID key fob.

How to copy HID cards and get them on your phone?

People ask questions like: “How can a mobile’s NFC be used as an HID proximity card (used at the doors of a corporate office)? “and “Is the iPhone 6’s NFC transmitter capable of being used as a contactless card reader?” and so on.

In the following segment, we’ll focus on your typical HID card, which works off of 13.56 MHz and is a bit more advanced to copy:

Why are these cards more difficult to copy?

Since the frequency is significantly higher than the 125 kHz version, the amount of bits that can be sent per second is significantly higher. That means the data on the chip to be encrypted will be greater, rendering it more secure.

Now that encryption is available for these cards, they communicate with a reader device to send out a signal, and the reader reads it. Unlike before, however, it no longer advertises all of its data; instead, it only broadcasts public data—like its ID and name.

How do we copy them?

To access sensitive information, you must provide that memory sector with the right key—otherwise, it will appear blank.

Even though these cards are much more secure, once you know the encryption algorithm, you can decrypt them and access sensitive information. With that, people can also clone these cards relatively easily.

Since most Android smartphones running the Android OS have NFC, reading these cards and sometimes cloning them is easy.

—(If you don’t want to order equipment on eBay, skip over this part and learn how to duplicate the card using a smartphone and an app)—

  1. Prepare to copy your HID cards—the tools you need: We need a few cheap components from eBay—it’s sold under “NFC reader.” You can also check the NFC reader on Alibaba for higher volumes. I got my NFC reader/writer on NewEgg, which lists it as the “NFC ACR122U RFID” reader/writer tool. It runs on Windows, Mac, and most Linux systems.
  2. Once you have the copy tool, you need a Windows-based computer. Install its drivers and start using it. You’ll also need a computer to run the software, and following this guide, you can hack Mifare Classic 1K Cards. Here’s the BlackHat Guide.

Hold on! I hope you haven’t ordered the NFC reader yet because if you have an Android, you can do it with your phone!

Cloning Mifare NFC cards with a mobile phone:

Here’s the easiest way to copy NFC cards to a phone:

Although the BlackHat guide works well, it can be frustrating since you have to get some components together and hack away at a guide for an hour or two to see some results.

The easiest way to clone Mifare NFC Classic 1K Cards is by using an Android smartphone with NFC capabilities. That’s right; your cellphone can be used to compromise a company’s security if they are using these types of cards (RFID security system).

Just download the “Mifare Classic Tool” for Android. Pro Tip: It took me a while to figure out why it doesn’t work, but you must turn on NFC. Go to your settings and search for NFC; enable it. We can start cloning cards that have never changed their default sector password.

How is the app used to copy the card?

The app comes with the default keys set by the manufacturer of NFC cards; you would not believe how many people never bother to change this. Tim Theeuwes has a great guide on cloning NFC cards using your NFC-enabled smartphone. The following images are from his guide, which can be found here.

Hacking NFC via an app:

Once we have read the key or fob we want, we can store all of the information in a file. We can then write this information back onto a blank card, essentially cloning the original or fob. Figure 5 below shows the “Write Sector” portion of the app, where you can write individual sectors or all of them.

The critical sector to remember is sector 0, which contains the UID and manufacturer’s data; if you copy sector 0 to another fob, you’ve made a copy.

The Reader Pro uses the Mifare Desfire EV1 2K NFC cards, some of today’s most secure NFC cards. They provide an added security level to the existing Mifare Desfire NFC cards, making them incredibly secure.

Mtools with ACR122u or PN532

MTools is a mobile application, typically used on Android devices, that allows you to read from and write to MIFARE Classic 1K and 4K cards, which are RFID cards operating at a frequency of 13.56 MHz. It’s often used with an external NFC reader/writer, such as the ACR122U or PN532.

Here’s how you can use MTools with these readers:

  1. Install MTools on Your Device: You can download and install MTools from the Google Play Store.
  2. Connect Your NFC Reader/Writer: The ACR122U or PN532 can be connected to your Android device via USB. Some newer Android devices may require a USB-C to USB-A adapter.
  3. Launch MTools and Select Your Reader: When you open MTools, you can select your NFC reader/writer from the options in the app.
  4. Read/Write Cards: Once your reader is selected, you can use MTools to read from or write to compatible MIFARE Classic cards. Follow the prompts in the app.

Remember, it’s essential to use this technology responsibly. Always respect privacy and legal boundaries when dealing with RFID and NFC technology. Unauthorized copying or cloning of RFID cards can potentially be illegal or unethical.

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About Author

  • Vincent Zhu

    Vincent Zhu has 10 years of smart lock system experience and specializes in offering hotel door lock systems and home door lock system solutions from design, configuration, installation, and troubleshooting. Whether you want to install an RFID keyless door lock for your hotel, a keyless keypad door lock for your home door, or have any other questions and troubleshooting requests about smart door locks, don't hesitate to contact me at any time.