I quote from Debian Wiki (https://wiki.debian.org/WiFi/HowToUse) :
"Restrict the permissions of /etc/network/interfaces, to prevent pre-shared key (PSK) disclosure (alternatively use a separate config file such as /etc/network/interfaces.d/wlan0 on newer Debian versions): " What should I put in the file called wlan0? Said wiki does not provide examples. Best regards. Stella
