So i did inctruction from this site: http://wiki.archlinux.org/index.php/Using_SSH_Keys

scp got same error, and when logging using ssh i got:Agent admitted failure to sign using the key.
If on server i set chmod 777 ~/.ssh/ then ssh error wont appear, but scp error is still there.

Generally, ssh is configured not to allow root logins. There are very good reasons for this.

So you should not be using sudo scp ...

The permissions on your ~/.ssh/ directory must not be set as 777 because this reduces your security to "no security at all".

You need to learn that ssh is the secure shell.

As such, it will refuse to work if it thinks your configuration is not secure. This is the correct behaviour for a properly crafted security tool: "If I am not set up correctly, then do not work, because otherwise users might think they are secure, but they are not, because ssh is not set up properly".

There are many HOWTOs on the internet, but try these for a start:

http://sial.org/howto/openssh/publickey-auth/
http://www.cyberciti.biz/tips/linux-...practices.html

I did everything from this tutorial and i dont have "Agent admitted failure to sign using the key." error anymore.
But still can't use scp! Still got "Host key verification failed." error.
I deleted key from known_hosts and that didn't help either.