Why is it difficult to scan citizen ID for biometric authentication?

From July 1, people must authenticate biometrics when transferring money online over VND10 million at a time or VND20 million accumulated per day. However, according to a survey conducted by reporters on June 24, 87% of more than 14,000 readers had difficulty scanning their ID cards with smartphones. Only 13% said the operation was normal. Some readers tried many ways but failed and said that the NFC chip on the ID card was malfunctioning.

Mr. Huy Nguyen, co-founder of Phygital Labs - a startup specializing in in-depth research on solutions related to NFC to identify digital objects, said: "The probability of an NFC chip on a card or smartphone being faulty can happen but is extremely small."

According to him, to explain why NFC scanning is difficult, we first need to understand how this technology works.

What is NFC?

NFC stands for Near Field Communication. This is not a new technology, developed from RFID (Radio Frequency Identification) technology for many decades. A series of devices in life are applying this technology, such as elevator magnetic cards, automatic toll cards on the road. Closer to home, the mobile payment features of Apple Pay, Samsung Pay or Google Pay all use NFC technology.

RFID and NFC work on the principle of inductive coupling. The biggest difference between the two technologies is the transmission range. While RFID can be read from a few dozen meters away if the tag is powered, NFC has a maximum operating range of a few centimeters. This is to limit the possibility of accidental activation, helping to secure sensitive data.

"Technically, NFC is a static chip, does not use batteries, does not use electricity, and does not emit signals by itself. It is only 'awakened' when charged with a magnetic field. Therefore, in addition to the chip attached to the card, NFC needs an additional reader, in this case a smartphone," Mr. Huy explained.

Smartphones that support NFC scanning will transmit a magnetic field through a coil. When placed near an NFC-enabled card, the magnetic field creates an electric current and "calls the NFC on the card", then transmits data wirelessly to the smartphone. This mechanism makes it difficult for many people to operate on NFC because the reader and the chip must be placed close together, accumulating enough magnetic field to be able to start.

Factors affecting NFC data transmission

From research and real-life customer experience, Mr. Huy said the two factors that affect NFC scanning are user behavior and technology.

First is user behavior. Many people determine the location of the NFC chip on the card, of the reader on the smartphone, so they do it by continuously scanning the location.

"As explained how NFC works, users need to fix the chip, place the device close enough and give the smartphone time to read. Scanning the card causes the chip to lose connection before it has enough magnetic field to transmit data. After a few unsuccessful attempts, many people panic, thinking that the phone has a problem, the chip on the card is faulty and are impatient to do it again," said Mr. Huy.

According to the co-founder of Phygital Labs, this causes more than 90% of failed NFC scans.

The remaining probability is due to technical factors. In particular, the antenna is the most important part of the NFC chip. "The larger the chip, the larger the antenna. If the chip is too small, scanning will be difficult. The chip on people's current cards has almost no problem with size," said Mr. Huy. He did not rule out the possibility that the phone supports NFC but the card reading microchip is faulty, this probability is "very small" but still possible.

Another factor that affects data transmission is the surface of the chip being covered. Since NFC is activated by a magnetic field, if the chip is covered by a metal layer, the energy will be dispersed, not enough to "wake up" the NFC chip on the card, the scan will also fail. Or when underwater, the chip does not have a waterproof circuit, which will also affect data transmission.

Regarding the fact that with the same smartphone and a chip-embedded CCCD card, people can scan NFC on public applications such as VNeID but encounter errors on some banking applications and e-wallets, experts say this comes from the priority order on the device or application.

"For example, on an iPhone, the device will perform multiple tasks at the same time, in order of priority such as searching for wifi and then 4G. NFC is usually placed in the last group. Some people open the application, scanning NFC will be faster and more stable because the developer has rewritten the device's priority order, depending on the purpose such as payment or sending messages," said Mr. Huy.

Notes for successful NFC scanning

Most smartphones on the market support NFC. Apple has integrated this technology since the iPhone 6, but it was not until the iPhone X that the company expanded the ability to read more NFC chips.

Before scanning, users need to determine if their smartphone supports NFC and enable it if necessary. On iPhone X and later, go to Settings -> Shortcuts -> Automation -> NFC -> Enable. On Android smartphones, go to Settings -> Connections -> NFC -> Enable.

Next, you need to locate the NFC chip on the card and the reader on the smartphone. On the chip-mounted CCCD, the NFC is hidden under the red seal area, not the exposed copper chip cluster. On the iPhone, the chip-reading antenna is usually on the back, near the top edge of the device. On Android devices, each manufacturer places it in a different location.

When scanning, users should fix the card on a flat surface, then put the phone in the correct position, hold it still and wait for the connection. Some factors such as the case, plastic bag protecting the CCCD can also affect the signal transmission.

Finally, if you have tried following the instructions but failed, you should go to the nearest bank counter for direct support.