1. Magnetic Stripe Cards
A magnetic stripe card is made by coating a plastic sheet with a layer of magnetic particles. When first produced, the magnetic particles on the card are not magnetized, making the card like a blank sheet of paper. To use the card, information needs to be encoded onto it. So how is the information recorded? This is done with the help of a recording head. The recording head is a device that generates a magnetic field proportional to the current flowing through it. When the card is passed through the recording head, the magnetic particles on the card are magnetized. If the signal current changes, it can represent specific information, and the magnetic particles on the card will be magnetized to varying degrees in line with the current changes. Once the card is magnetized, it retains a magnetic pattern that corresponds to the current’s variations, effectively storing the information and giving the card its identity. By following predetermined rules, the information on the card can be read when needed. As seen from this, the working principle of magnetic stripe cards is similar to that of cassette tapes.
The advantages of magnetic stripe cards are that they are easy to read and write, and cost-effective. However, their drawbacks include being prone to wear and interference from other magnetic fields. Therefore, it is best not to store them with items like mobile phones or keys, as the magnetic field from a phone can demagnetize the card, and keys may scratch the magnetic strip.
2. ID Cards
ID cards, also known as identification cards, are non-writable contactless cards that come with a fixed card number. Once the card number is written before the card is sealed, it cannot be changed, ensuring the uniqueness and security of the card number. ID cards are commonly used for user identification in access control systems or parking systems. However, since ID cards lack key-based security authentication mechanisms and cannot store additional information, they are not suitable for integrated systems that require multiple functionalities on one card, such as payment systems.
Since ID cards only store an identification number and devices merely recognize the ID number without any encryption algorithms, they are easy to duplicate and offer low security.
3. IC Cards
Magnetic stripe cards store information through changes in the magnetic field of the stripe, while IC cards store data using an embedded integrated circuit chip, specifically an Electrically Erasable Programmable Read-Only Memory (EEPROM).
IC (Integrated Circuit) cards were invented in 1970 by Frenchman Roland Moreno. He first encapsulated an integrated circuit chip in a small copper plate, then embedded it into a plastic card, creating the world’s first IC card. The terms “IC card” and “magnetic card” refer to the technology used, and should not be confused with cards named based on their application, like credit cards or phone cards, which can come in both magnetic stripe and IC card forms. Since the introduction of IC cards, they have been called by various names internationally. In English, they are known as “Smart Cards” or “IC Cards”; in Asia, especially in Hong Kong and Taiwan, they are referred to as “smart cards” or “intelligent cards.” In mainland China, they are typically abbreviated as “IC cards.”
An IC card consists of a plastic base, often printed with patterns, text, and numbers, referred to as the “substrate.” A specific IC chip is embedded in a fixed position on this substrate. This chip is the most visible way to distinguish between a magnetic stripe card and an IC card. Different types of IC cards arise depending on the chip embedded.
IC Card Classification:
The first method of classification
for IC cards is based on the type of integrated circuit chip embedded in the card. There are two main categories: memory cards and CPU cards (also known as smart cards).
Memory Cards: These use memory chips as the core of the card and consist only of hardware. They include data storage and basic security logic control, but do not have any processing capabilities.
CPU Cards (Smart Cards): These cards use microprocessor chips as the core, combining both hardware and software. They function as a complete microcontroller system on the card, offering more advanced features such as data processing and security authentication.
Second Classification Method:
IC cards can also be classified based on the method of data reading and writing: contact IC cards and contactless IC cards.
- Contact IC Cards: These are widely used today and can be recognized by a square gold-plated interface on the surface, typically with six or eight gold contacts. These contacts are used to interact with a reader through electrical signals for data read and write operations. The card exchanges information with external devices via the contact points that are exposed on the card’s surface. For example, phone cards with a small metal chip are this type. During read and write operations (commonly known as swiping), the IC card must be inserted into a reader, and after the operation, the card is either ejected or manually removed. Contact IC cards are slower when swiped but are highly reliable, making them suitable for applications where large amounts of information are stored, and complex read/write operations are needed.
- Contactless IC Cards: These use the same chip technology and features as contact IC cards, but the key difference is that they have radio frequency (RF) or infrared transceivers embedded in the card. This allows them to communicate with the reader without physical contact, within a certain range. The basic working principle involves the external device sending an electromagnetic wave to the IC card, which has an LC resonant circuit that matches the frequency of the emitted wave. When excited by the electromagnetic wave, the LC circuit resonates, generating a charge in the capacitor. Once the accumulated charge reaches 2V, the capacitor acts as a power source for other circuits, enabling the card to either transmit data to or receive data from the reader. Public transportation cards, for instance, are contactless cards, allowing passengers to make payments without removing the card from their bag. Contactless IC cards with embedded RF transceivers are referred to as “RF cards” or “radio-frequency cards.” These are often used in scenarios such as identity verification or electronic access control. The information stored on these cards is simple, with minimal read/write requirements, and they can come in various forms, such as badges.
- As a result, contactless IC cards not only store large amounts of data and offer strong security, but they are also resistant to interference, wear and tear, and have a long lifespan. This makes them widely applicable in various fields.
Third Classification Method:
IC cards can also be classified based on their application field into two major categories: financial cards and non-financial cards.
Financial Cards: These are primarily used in banking and are the core medium of the national “Golden Card Project” in China, which aims to develop a unified financial card system. Financial IC cards are issued and managed by banks. Since the card stores key information about the cardholder, it does not always require the point of sale to be connected to the bank’s network during transactions. Compared to magnetic stripe cards that only store a small amount of data, financial IC cards offer much greater flexibility and reliability.
Non-Financial Cards: These cards are mainly used as electronic identification tools to record various information about the cardholder, serving as identity verification. Examples include IC card-based ID cards, student ID cards, access cards, attendance cards, medical cards, and accommodation cards. Since IC cards can store a large amount of data and have the capability to partition data storage, they can be used for multiple purposes with a single card, simplifying the verification process.
Security of M1 Cards and CPU Cards
M1 Cards
M1 cards are produced by NXP (formerly Philips) and are a type of contactless IC card used in applications like campus cards and transit cards. They store an ID number and can read and write data. In an M1 card system, the card sends data to the reader, and the reader responds with data to confirm the transaction or authentication. The security mechanism relies on a single algorithm, which can potentially be intercepted and exploited. While M1 cards offer more security than ID cards, they can still be compromised. There have been demonstrations of M1 card hacking showing that with the right software and simple DIY equipment, the card can be copied. Some claim that M1 cards with unique keys for each card prevent hacking, but this is not entirely accurate; such cards can still be hacked, although only one cloned card can be compromised at a time. The drawbacks include a relatively higher cost, shorter sensing distance, and suitability primarily for non-consumable systems, parking systems, and access control systems.
CPU Cards
For higher security needs, CPU cards are a better choice. A CPU card contains a microprocessor, functioning much like a miniature computer. CPU cards are suitable for various fields such as finance, insurance, law enforcement, and government. They offer large storage capacity, fast read speeds, and support for multiple functions on one card. Although CPU cards may appear similar to standard IC cards or RF cards, their performance and security are significantly enhanced. They typically include features such as random number generators and hardware encryption algorithms like DES and 3DES. When paired with a secure operating system (COS) on the CPU chip, they provide financial-grade security.
