CAcert user trusted certificates (with lockscreen)
Users may meet credential problems in their application sometimes. In order to install credential, we need to install the certificate files in our media player.
Download the certificate files onto the internal flash storage (the '/sdcard' or any subfolder).
You can find the install options in below path.
Basic setting page->Click Time zone->Security->Credential storage->Install from SD
If it is the first user certificate you install, the Android Security Model forces you to use a lock-screen to unlock your device. Check if certificate files are installed correctly, you can see the certificates under Security -> Certificates -> 'User'-section.
For step by step instructions, please download attachment.