To protect your data from cyber threats or any information leakage while connected to various devices, using a valid certificate on your Synology NAS is recommended.¹ If you're not using a Let's Encrypt certificate, such as a self-signed certificate, importing the certificate to an Android/iOS device is required. This article will guide you on how to manually import an existing certificate into your Android/iOS device.

Importing an existing certificate

For iOS devices

1. Upload the certificate file on DSM > File Station.
2. On your iOS device, go to DS file and locate the certificate file that you want to import.
3. Tap the horizontal ellipsis > Share,and then choose Save to Files to save the certificate file on your iOS device’s local storage.
4. On your Files app (an iOS built-in app), locate and tap on the certificate file. The "Profile Downloaded" message will appear, and then tap Close.
5. Go to Settings and tap Profile Downloaded.
6. Tap Install on the Install Profile page and enter the passcode to proceed.
7. Tap Install on the Warning page and tap the Install button again to confirm the installation.
8. Tap Done on the Profile Installed page.
9. Go to Settings > General > About > Certificate Trust Settings. Under Enable full trust for root certificates, turn on the toggle switch for your trusted certificate.

For Android devices

Due to the variety of available Android devices on the market, the installation methods, UI, and steps may vary. Refer to this tutorial or contact your device manufacturer for further assistance.