sudo asks for the user password. Thus, changing the user password (which is also used for login), will also affect sudo invocations.
However, you can set in the
/etc/sudoers for your user the
rootpw flag, in which case it would ask for the root password instead.
The relevant excerpt from the sudoers(5) man page is:
Authentication and logging
The sudoers security policy requires that most users authenticate them‐
selves before they can use sudo. A password is not required if the
invoking user is root, if the target user is the same as the invoking
user, or if the policy has disabled authentication for the user or com‐
mand. Unlike su(1), when sudoers requires authentication, it validates
the invoking user's credentials, not the target user's (or root's) cre‐
dentials. This can be changed via the rootpw, targetpw and runaspw
flags, described later.
Similarly, the keyword for not requesting a password for sudo is NOPASSWD.
If you want to set the root password, you can use
Note that when changing sudo permissions, it is recommended to keep a root console open (eg.
sudo -s) until it is verified in a different terminal that it indeed works, and you haven't locked out yourself.