У вашего броузера проблема в совместимости с HTML5
KDE seems in a sad state when it comes to being able to use encryption.
File encryption on KDE via Kgpg is hit and miss at best, there are lots of complaints on the net where Kgpg refuses to start. You need to use a terminal to start Kgpg for keys or clipboard work, although it should start from the menu... This is how to set it up and use it. Normally your keys are not set to expire and you should make a revocation cert.
Here I'm using using Kgpg in SolydK - Debian Linux.
Kgpg refuses to start and brings up the error gpg: option file `/home/username/.gnupg/gpg.conf': No such file or directory = Paste the following info into a terminal -
kwriteconfig --file kgpgrc --group "GPG Settings" --key "gpg_config_path" --type string "$HOME/.gnupg/gpg.conf"