Sudo timeout in wich debian/ubuntu systems doesn't ask for password is 15minutes, if i remember well.
In any case, you could invalidate the last password given by "sudo -k"
[501]gaspa@saturnino:~$ sudo -i
[sudo] password for gaspa:
root@saturnino:~# exit
[502]gaspa@saturnino:~$ sudo -k
[503]gaspa@saturnino:~$ sudo -i
[sudo] password for gaspa:
root@saturnino:~#
Sudo timeout in wich debian/ubuntu systems doesn't ask for password is 15minutes, if i remember well.
In any case, you could invalidate the last password given by "sudo -k"
[501]gaspa@ saturnino: ~$ sudo -i saturnino: ~$ sudo -k saturnino: ~$ sudo -i
[sudo] password for gaspa:
root@saturnino:~# exit
[502]gaspa@
[503]gaspa@
[sudo] password for gaspa:
root@saturnino:~#