How to Update Kali Linux

If you try to update Kali with
apt-get update
and you see these errors: 
W: GPG error: http:// http. kali. org kali Release: The following signatures were invalid: KEYEXPIRED 1425567400 KEYEXPIRED 1425567400 KEYEXPIRED 1425567400
W: GPG error: http://security. kali. org kali/updates Release: The following signatures were invalid: KEYEXPIRED 1425567400 KEYEXPIRED 1425567400 KEYEXPIRED 1425567400
This is the solution:
rm -rf /var/lib/apt/lists

apt-get update

apt-get install kali-archive-keyring

apt-get update

Source

http://superuser.com/questions/890383/kali-linux-update-fails

Posted 4-18-15 by Sam Bowne