QR Code Security - Tips for Safe Usage

Security Risks Hidden in QR Codes

QR codes offer the convenience of accessing URLs simply by pointing a smartphone camera, but this ease of use also introduces security risks. The biggest concern is that you cannot verify the destination URL just by looking at a QR code.

With traditional text links, you can visually inspect the URL before clicking. QR codes, however, encode information in a pattern of black and white dots that humans cannot decipher. This characteristic has led to a growing number of attacks exploiting QR codes worldwide.

Common Attack Methods

There are several patterns of attacks that exploit QR codes. Understanding these common techniques is the first step in defense.

• QR Phishing (Quishing): Distributing QR codes that redirect to fake websites impersonating legitimate services. Attackers pose as banks, payment services, or delivery companies to steal login credentials and credit card numbers. Cases of QR codes embedded in phishing emails are also increasing.
• QR Code Overlay: A physical attack where criminals place a fraudulent QR code sticker over a legitimate one at stores or public facilities. Cases of parking payment QR codes being replaced have been reported internationally.
• Malware Distribution: Directing users to download malicious apps through QR code links. Fake messages like "A security update is required" trick users into installing rogue applications.
• Malicious Wi-Fi Connection: Placing QR codes that automatically connect devices to a malicious Wi-Fi network, enabling traffic interception. This risk is particularly relevant in public spaces like cafes and airports.

Security Measures for Individual Users

Here are practical security measures that individual users should follow when using QR codes in daily life.

• Check the URL after scanning: Always verify the URL displayed before your browser opens it. Check whether it is a legitimate domain and whether it contains suspicious strings.
• Verify HTTPS: Confirm that the destination starts with HTTPS. Sites using only HTTP do not encrypt communications, creating a risk of information interception.
• Be cautious with public QR codes: QR codes posted at parking lots, restaurants, and public transit may have been replaced. Check whether stickers appear to be layered on top of each other and whether the code is naturally integrated into the printed material.
• Keep your OS and apps updated: Updating your smartphone's OS and browser to the latest version helps prevent attacks that exploit known vulnerabilities.
• Avoid scanning suspicious QR codes: Do not scan QR codes of unknown origin, codes posted on the street, or codes included in suspicious emails.

Security Measures for Businesses and Stores

Businesses and stores that use QR codes in their operations need measures to prevent their codes from being exploited and to protect their customers.

• Regular QR code inspections: Periodically check that QR codes posted at your premises have not been replaced. Codes in publicly accessible locations require extra vigilance.
• Manage shortened URLs: If your QR codes use shortened URLs, a compromised URL shortener account could allow attackers to redirect the link. Enable two-factor authentication and regularly review access logs.
• Use dynamic QR codes: Dynamic QR codes allow you to change the destination URL after creation, enabling immediate deactivation if issues arise. However, verify the security of the dynamic QR code service itself.
• Display the URL alongside the QR code: Printing the destination URL as text near the QR code allows users to visually verify the link, increasing resistance to overlay attacks.
• Employee security training: Train staff who handle QR codes on how to check for replacements and how to report suspicious codes.

QR Code Payment Security

QR code payments are widely adopted in Japan, but since money is directly involved, heightened security awareness is essential.

• Merchant-Presented Mode (MPM) risks: In this mode, the store displays a QR code and the customer scans it to pay. There is a risk that the QR code could be replaced, redirecting payments to an attacker's account.
• Consumer-Presented Mode (CPM) safety: In this mode, the store scans a QR code displayed on the customer's smartphone. Since the code is dynamically generated with a short expiration, CPM is considered more secure than MPM.
• Protect your payment app: Enable biometric authentication or passcode lock on payment apps to prevent unauthorized use if your smartphone is lost.

For QR codes involved in payments, the balance between convenience and security is particularly critical.<% if (typeof amazonTag !== 'undefined' && amazonTag) { %> For a deeper understanding of cashless payment systems, books on cashless payment are a helpful resource.<% } else { %> For a deeper understanding of cashless payment systems, books on cashless payment are a helpful resource.<% } %>

Summary of Safe QR Code Usage

QR codes are extremely useful tools when used correctly, but it is important to understand the security risks involved. Here is a summary of key points:

• Always check the URL after scanning and avoid accessing suspicious links
• Be skeptical of QR codes posted in public places as they may have been replaced
• Keep your OS and apps up to date at all times
• Businesses should conduct regular QR code inspections and provide employee training
• Handle payment QR codes with extra care and strengthen app security settings

To safely enjoy the convenience of QR codes, maintain security awareness in your daily usage.