Re: [Trisquel-users] WARNING: The following packages cannot be authenticated!

[freeworld4]

I tried this
$ sudo apt-key update
$ sudo apt-get update
Then $ sudo apt-get install packagename
Source:  
https://askubuntu.com/questions/75565/why-am-i-getting-authentication-errors-for-packages-from-an-ubuntu-repository  
accessed 10-19-15