Smartphone Security Measures

On Android smartphones, you can install apps from providers other than the Play store (Google Play) and other carrier-provided official markets. These unknown apps, or apps from unknown sources, may not be sufficiently verified to be safe, and therefore as a general rule, you should not install such apps.
Android smartphones are initially set to block installations of unknown apps or apps from unknown sources. When you attempt to install such an app, a warning will be displayed. You can still install such apps by allowing installation of apps from unknown sources or apps from a particular source, but this setting does not need to be turned on for normal use.
Keep this setting turned off unless you are completely aware of the risks.

On another note, while it is possible for you to click an app file (APK file) attached to a message and install it on your Android smartphone, generally APK files are not attached and sent via emails. In most cases, they contain malware. You should ignore such messages from unknown senders, but even messages from people you known can be impersonated. Unless you can be sure that such files are safe by checking with the sender in person or over phone, it is better not to install such attachments.

Biometric authentication using fingerprints and face recognition is a safer alternative authentication method to authentications using a login ID and password. Not using a password simply reduces the risk of unauthorized login by a third party that steals passwords from phishing sites. Active use of biometric authentication is recommended when using services that offer biometric authentication.

KDDI's "login by fingerprint and face recognition" uses the smartphone's device lock function. Use a PIN code for device lock that cannot be guessed easily so that you can protect your smartphone in the event of theft or loss.

Information generated in the device for biometric authentication (called "private key") is also shared with Google Password Manager and iCloud Keychain, which means that once your Google account or Apple ID is compromised, all of the services that you have set up biometric authentication for can suffer unauthorized access. Be careful about how you manage login information (including passwords and secret questions) of management services that share a private key.

For some services, you can achieve secure authentication by using an authentication app.
Authentication apps are generally used as additional login authentication. As authentication apps use a smartphone-generated authentication code that is only valid for a short period of time, there is little concern for password peeping or interception and you can securely log in.
However, you need to keep in mind that, for services that use emails or SMS for resetting the authentication app, there is still a risk of a third party resetting the authentication if your email account is taken over or your SMS is intercepted.

When you set up an authentication app to be used for a service, you are prompted to enter an authentication code after entering your login ID and password. You then check your authentication app for the authentication code and enter that code to log into the service.

Examples of such authentication apps are Google's Authenticator app and Microsoft's Authenticator app. While iOS (iPhone) does not have such apps, it provides a password management function that you can access from Settings - Password.

Authentication on X

You can use a password management app that is installed separately from the services that you are using.
By using a password management app, your device can identify the URL of the website of the service and automatically enter the corresponding ID and password. This saves you from needing to remember the password, which makes it easier for you to use more complex, safer passwords.
Additionally, this allows you to notice that something is wrong when the automatic password entry is not working. If automatic password entry does not work on a website that appears to be the one that you are familiar with, you can suspect that it may be a cunningly disguised phishing site.

A password management app is also available from au.
This is also available to UQ mobile and povo users by subscribing to au Smart Pass Premium.

• Password management: Data storage (For au users) (in Japanese only)
• Data storage (For UQ mobile/povo users) (in Japanese only)

• If you have not registered for au ID, you can register from here (in Japanese only).

Using simple passwords creates an increased risk of unauthorized access by brute-force attacks or dictionary attacks.
Even when you are using a complex password, if you are sharing it with other websites and it leaks from one of them, it is no longer safe to use.

To ensure password security, it is important to set a strong password and not share one password across multiple websites.
Since remembering all of your passwords can be difficult, consider using a password management app as mentioned above.

Set a screen lock when you purchase a smartphone. A screen lock can reduce the risk of someone else seeing the information in your smartphone in case you misplace your smartphone.

A remote lock function and location search function are provided as preparation in case your smartphone is lost or stolen. Setting these functions in advance is recommended. With these functions, you can remotely lock your smartphone and/or delete data on your smartphone to prevent information leaks in case of loss or theft.

If your smartphone is lost or stolen, you may lose important information saved on your smartphone. There may be cases where you have to delete data on your smartphone using the remote support function to avoid leakage of important information.
It is recommended that you make a backup of your smartphone data so that you can recover data later even if you end up losing the data on your smartphone.
au provides a data storage service that saves the photos, contacts, and other important data saved on your smartphone to au's servers.
This is also available to UQ mobile and povo users by subscribing to au Smart Pass Premium.

Data storage (in Japanese only)

You can safely use Wi-Fi by connecting to a Wi-Fi service provided by a telecom carrier.
au provides Wi-Fi services at stations and cafés.

• au Wi-Fi SPOT (For au users) (in Japanese only)
• au Wi-Fi Access (For UQ mobile/povo users) (in Japanese only) Use of au PAY is required.

With public Wi-Fi, many people share the Wi-Fi-network to connect to the Internet. Therefore, a Wi-Fi network without sufficient security leaves a chance of having your transmitted or received data tapped by a third party. As an approach to use Wi-Fi networks safely even in such environments, you can use a VPN to protect your communications. When using a VPN, communications take place over a virtual dedicated network, which prevents data tapping by a third party.

au Wi-Fi Access (in Japanese only) provides a security mode that offers a VPN when using a Wi-Fi service.

• Subscription to au Smart Pass Premium is required.

When downloading an app from App Store, you will see "App Privacy" displayed at the bottom of the app download screen, and by tapping [See Details], you can view what kind of data that app may handle.

When downloading an app from Google Play, you will see "Data Safety" displayed at the bottom of the app download screen, and by tapping [See details], you can view what kind of data that app shares and collects.

This function protects your smartphone from installing malware from email attachments and phishing and other dangerous websites.
However, security software is not a be-all-end-all solution and cannot defend against all dangers. Do not put excessive trust in security software-simply avoid accessing suspicious websites.

This function detects dangerous Wi-Fi networks and stops your smartphone from connecting to detected dangerous networks.
In some cases, this function may come with a function that performs VPN connection for Wi-Fi connections. For a detailed explanation of VPN connections, see "Using Wi-Fi carefully."

This function detects phishing and other malicious websites and displays a warning similar to a warning screen on a Web browser, preventing you from accessing such websites when you make an attempt. This function prevents unauthorized access based on the security software company's information.
Likewise the warnings in Web browsers, users are not warned on all unsafe websites, so you cannot be too careful even when a warning screen is not displayed.

Dark Web refers to a part of the World Wide Web that is "underground" and cannot be searched by normal search engines. On the dark Web, cyber-criminals trade personal information such as email addresses, and the dark Web monitoring function checks whether the user's personal information is being traded on the dark Web.

Since different types of security software support different functions, it is necessary to thoroughly check what functions you need before making a selection. Some products are also provided combined with computer security software, which is another option that you can select according to your usage needs.
KDDI offers security software at au Style/au shops.
It can also be purchased at the au Online Shop (see sales page for sales conditions, etc.).
au Online Shop (in Japanese only)

In addition, if you are using an Android smartphone, you can subscribe to au Smart Pass Premium to use Virus Block, which prevents virus infection.
Virus Block (in Japanese only)