SSH use key cannot log into Linux system

Today the test key is logged into the Linux system with the following issues:

[Email protected]:~# ssh [email protected]-P 80-i alickicxxxxxxx.key

@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@
@ warning:unprotected PRIVATE KEY file! @
@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@
Permissions 0777 for ' Alickxxxxxxx.key ' is too open.
It is required this your private key files are not accessible by others.
This private key would be ignored.
Bad Permissions:ignore Key:alickicxxxxxxxxxxx.key
Permission denied (PublicKey).

Workaround:

chmod Alickicxxxxxxxxxxx.key

Then try it again. To restrict other users from using this key first. This key can only be used by the root user.

SSH use key cannot log into Linux system