Actually a Super-Small, High-Performance Computer? The Mechanism Behind Familiar Smart Cards is Surprisingly Unknown

When transportation smart cards first appeared in 2001, many people were amazed by the convenience of passing through ticket gates with just a tap. Today, cards with IC chips are an indispensable part of daily life and are widely used in transportation, cash, credit, and smartphone SIM cards, as well as government-issued cards like driver's licenses and Japan's Individual Number Cards. Here, we will introduce the structure and mechanism of smart cards and their latest features.

• Smart cards are like tiny brains!
• Smart cards decide how to communicate based on the application
• Even with fingerprint authentication property! ― DNP's strengths spur the evolution of smart cards

Characters

Katsujii... Kinzoku Katsujii is like a living encyclopedia: his career as a movable type spans over 100 years. Here, he shares his extensive knowledge of the DNP Group, teaching all kinds of things with his many years of experience.

Tonbo-chan... A character born from the tonbo register marks* used to align printed materials. She has a meticulous personality, hates anything misaligned, and supports Katsujii with her careful attention to detail.

A smart card is embedded with an Integrated Circuit (IC) chip. The chip consists of a central processing unit (CPU, often called the brain of a computer) and memory, giving it a basic structure nearly identical to that of a personal computer. However, because smart cards do not have their own power source, they require a card reader or other external source of electricity to be used.

Black magnetic-striped cards that were standard before smart cards simply read the information recorded on the magnetic stripe with a card reader. Smart cards, however, receive inquiries from the card reader, and the IC chip itself processes information and responds. More specifically, smart cards communicate with the card reader. The IC chip's programming performs operations such as authenticating the reader to verify it is not counterfeit and exchanging data related to card lock features.

Using two or more stacked cards should be avoided; this has to do with how contactless smart cards communicate, which we will discuss later. One reason is that in such cases the reader cannot determine which card it should exchange information with. Another reason is that, as mentioned earlier, smart cards are powered by the card reader, so if multiple cards try to communicate at the same time, there may not be enough power for them to function properly. However, some transportation smart cards are designed to allow multiple smart cards to be used stacked on top of each other.

There are various ways to classify smart cards, but here we will classify them by how they communicate and look at the three most common types of smart cards: contact, contactless, and dual interface.

The card reader comes into direct contact with the gold portion of the card with the built-in IC chip, which is often seen on the front. This allows for more stable communication. It is used for cards like ATM cards and credit cards that require stable connections for monetary and similar transactions.

These smart cards are basically made by laminating multiple layers. An antenna embedded in the card along with the IC chip sends and receives radio waves, allowing communication without direct contact with the card reader. They are used in transportation smart cards, driver's licenses, and more. They are also increasingly used in credit and prepaid cards with their growing use for small payments.

Equipped with both a contact terminal and a contactless antenna, these combine the functionality of both communication methods. This allows features to be added to the card, like enabling a contact credit card to also support contactless payments.

Let's look at how a typical contactless transportation smart card communicates with a card reader.

<Communication between a transportation smart card and a ticket gate when entering>

1. The ticket gate constantly emits radio waves within a roughly 10 cm range from its smart card touch panel to detect transportation smart cards.

2. The moment the transportation smart card comes within range of these radio waves, it receives a charge and starts operating.

3. The transportation smart card and the ticket gate exchange information, confirming they are each authentic.

4. The ticket gate writes information such as "Boarding from XX Station" onto the smart card and allows entry.

Contactless transportation smart cards can be communicated with by simply holding them over the reader. However, prompting an actual tap creates a brief interval between the card's initial detection and its steady positioning, which allows the data exchange to take place.

There are many different types of smart cards, and more advanced types are now available, including cards with fingerprint authentication feature.

A smart card with fingerprint authentication developed by DNP in 2021 integrates a fingerprint sensor into a widely used contactless FeliCa smart card. The card owner's pre-registered fingerprint data is stored on the card. When it is used, the sensor reads the user's fingerprint, compares it with the stored data, and only communicates with the card reader if they match. Smart cards have long been used for security purposes, similar to card keys. However, they cannot identify the user, making it possible for unauthorized users to use them. A smart card with fingerprint authentication, on the other hand, can only be used by its owner, providing extremely high levels of security. Fingerprint-authenticating smart cards will likely be used for applications like cards holding large amounts of electronic money and employee ID cards that control access to company premises.

Even with the new functionality such as a fingerprint authentication feature, a card's thickness must remain within the approximately 0.8 mm international standard limit. Contactless smart cards are made up of multiple layers, including the IC chip and antenna; DNP, which holds the top share of the smart card market in Japan, has utilized its extensive design technology cultivated over many years to successfully add this functionality without changing card thickness.

DNP's unique strength lies in its technological development capabilities, enabling it to build IC chip software from scratch. Another one is its manufacturing expertise, which allows it to create smart cards from diverse materials that meet strict requirements for shape, durability, and more. Together, these capabilities enable DNP to produce a wide variety of smart cards.

Recently, as the Japanese government has been promoting cashless payments, transactions using smartphones are on the rise. However, high-security smart cards, which can be used with simple actions such as inserting the card into a card reader or with just a tap, remain even more familiar to people in Japan. These cards are easy to use for people of all ages, making them universally valued. As various applications expand to include payments, identity verification, and membership cards, DNP will continue to develop advanced features that will create future standards.

Nowadays, with just a smart card, you can do everything from shopping to completing government paperwork... Now that's convenient.

That's right, smart cards are hard at work supporting life day-to-day. They may look like an ordinary card, but inside, they're packed with cutting-edge technology.

May 27, 2021 by DNP Features Editorial Department