SSH Permission Denied Error on EC2 Instances

Generate a new key from the source EC2 server [e.g. Ansible Master Node].

  $ ssh-keygen

Change the permission for the generated keys

  $ chmod 600 id_rsa.pub
  $ chmod 600 id_rsa

Copy the id_rsa.pub key entry to the authorized_keys in the target servers [e.g. Host Node]

When trying to connect to the target server, a permission denied error occurs:

To resolve, I changed the permission of the authorized_keys in the target server.

  $ chmod 600 authorized_keys