Understanding NFC and IC Smart Cards: A Comprehensive Guide

All the <span>cards</span> mentioned in this article, unless otherwise specified, are contactless cards and will not be stated otherwise.

Overview

Before analyzing NFC and the IC cards around us, we need to introduce some basic concepts:

Near Field Communication (NFC) technology evolved from contactless Radio Frequency Identification (RFID), developed jointly by Philips Semiconductors (now NXP Semiconductors), Nokia, and Sony in 2004. It is based on RFID and interconnection technology. NFC is a short-range high-frequency wireless technology that operates at a frequency of 13.56 MHz within a distance of 20 centimeters. Its transmission speeds are 106 Kbit/s, 212 Kbit/s, or 424 Kbit/s. Currently, NFC has become an international standard ISO/IEC IS 18092, EMCA-340, and ETSI TS 102 190. NFC operates in both active and passive reading modes.

Each complete NFC device can operate in three modes:

• Card Emulation Mode: This mode is equivalent to an IC card using RFID technology. It can replace the numerous IC cards currently in use (including credit cards) for shopping, IPASS, access control, tickets, etc. A significant advantage of this method is that the card is powered through the RF field of a contactless card reader, allowing it to work even if the host device (like a mobile phone) is out of battery. For NFC devices to perform card emulation (Card Emulation), they must have an embedded Security Element (SE) NFC chip or implement Host Card Emulation (HCE) through software.

• Reader/Writer Mode: Used as a contactless reader, for instance, to read information from electronic tags on posters or exhibition displays.

• Peer-to-Peer Mode: This mode is similar to infrared and can be used for data exchange, though it has a shorter transmission distance, faster creation speed, and lower power consumption (similar to Bluetooth). When two NFC-enabled devices connect, they can perform point-to-point data transmission, such as downloading music, exchanging images, or synchronizing device address books. Therefore, through NFC, multiple devices like digital cameras, PDAs, computers, and mobile phones can exchange information or services.

Source: zh.wikipedia.org/wiki/Near_field_communication

To summarize this lengthy explanation, the general idea is that NFC is a technology that allows data to be transmitted within a few centimeters. Common applications of this technology include our national second-generation ID cards, electronic passports, and public transport cards. There are many specific applications of NFC around us, and sometimes we mistakenly think they are implementations of other technologies. For instance, people often say that bank cards or public transport cards have been “demagnetized,” but in fact, these cards no longer use magnetic strips or other traditional magnetic materials to record data; instead, they support contactless RFID electronic chips. The failure of these cards is generally not due to damage to some magnetic material but rather physical damage to the coils or chips, such as bending the card or other similar technologies damaging the stored data, making it unreadable.

I won’t elaborate on traditional RFID technology here; just understand it as a special kind of wireless communication technology. NFC is limited to the 13.56 MHz frequency band, while RFID operates across low frequency (125 KHz to 135 KHz), high frequency (13.56 MHz), and ultra-high frequency (860 MHz to 960 MHz). NFC works effectively at distances of less than 10 cm, making it very secure, while RFID can operate effectively from a few meters to several dozen meters. There are many RFID standards, and unifying them is quite complex (it seems impossible to achieve uniformity), so relevant technical standards are adopted only in specific industries with special requirements. The most common application of traditional RFID is in libraries, where special tags are attached to books. These tags can be read over a relatively large range, allowing for convenient self-service book borrowing management. Readers can place books in a specific area to read which books have been borrowed, unlike traditional libraries where an administrator manually scans the barcode on the title page, greatly improving efficiency. Many logistics operations also manage transport boxes using similar methods, allowing for remote sorting and easier management. NFC has developed from such technology, making it more suitable for everyday use.

Are all the various cards we can swipe in life NFC?

The answer is clearly no. To determine if a card supports NFC technology, there are several methods:

1. Use a NFC-enabled Android phone to swipe. Although phone manufacturers often claim “full-featured NFC,” this only applies to the previously mentioned “card emulation mode.” When it comes to reading NFC cards, aside from the iPhone, there isn’t much difference among others. I recommend an app called “MIFARE Classic Tool,” which can be downloaded from GitHub and Google Play:

• Play: de.syss.MifareClassicTool

• GitHub: ikarus23/MifareClassicTool

• F-Droid: de.syss.MifareClassicTool

• I will add available domestic mirrors later Using this app, you can read some information from NFC cards, but this app does not support all NFC cards; it only supports MIFARE series and similar technology simulation cards (this issue will be discussed later). If this app does not respond, but other applications on the phone, such as QQ, WeChat, financial apps, etc., do respond to it, then this card is also a type of NFC card.

If the contactless cards we commonly use are not NFC cards, then what kind of cards are they? The most common ones are ID cards.

ID card, short for Identification Card, is a type of non-writable induction card containing a fixed number. Like magnetic cards, ID cards only use the