Binbin,
Password authentication is disabled for our AMIs. If you want to enable it you need to modify /etc/ssh/sshd_config file and set:
PasswordAuthentication yes
PermitRootLogin yes
We strongly do not recommend it as it is a quite big security risk. Use it at your own responsibility.
--Marek
On 25 paź 2011, at 02:58, Binbin Wang wrote:
> Thanks Marek, while I changed the passwd of the root user, I still need the key to ssh login the system?
>
> Are there any configuration I need to change? Then I can log in the system only with my root credential, instead of the key pair?