I just setup my new server as I used to, and this time I can't login using my private key. The server is ubuntu 11.04. And I have setup following ssh key directories. root@myserv: ls -la drwx------ 2 root root 4096 Sep 23 03:40 .ssh And in .ssh directory, I have done chmod 640 authorized_keys Here is the ssh connection tracebacks: OpenSSH_5.9p1, OpenSSL 0.9.8r 8 Feb 2011 debug1: Reading configuration data /etc/ssh_config debug1: /etc/ssh_config line 20: Applying options for * debug1: Connecting to [my.server.ip] [[my.server.ip]] port 22. debug1: Connection established. debug1: identity file /Users/john/.ssh/id_rsa type -1 debug1: identity file /Users/john/.ssh/id_rsa-cert type -1 debug1: identity file /Users/john/.ssh/id_dsa type 1 debug1: identity file /Users/john/.ssh/id_dsa-cert type -1 debug1: Remote protocol version 2.0, remote software version OpenSSH_5.8p1 Debian-1ubuntu3 debug1: match: OpenSSH_5.8p1 Debian-1ubuntu3 pat OpenSSH* debug1: Enabling compatibility mode for protocol 2.0 debug1: Local version string SSH-2.0-OpenSSH_5.9 debug1: SSH2_MSG_KEXINIT sent debug1: SSH2_MSG_KEXINIT received debug1: kex: server->client aes128-ctr hmac-md5 none debug1: kex: client->server aes128-ctr hmac-md5 none debug1: SSH2_MSG_KEX_DH_GEX_REQUEST(1024<1024<8192) sent debug1: expecting SSH2_MSG_KEX_DH_GEX_GROUP debug1: SSH2_MSG_KEX_DH_GEX_INIT sent debug1: expecting SSH2_MSG_KEX_DH_GEX_REPLY debug1: Server host key: RSA ef:b8:8f:b4:fc:a0:57:7d:ce:50:36:17:37:fa:f7:ec debug1: Host '[my.server.ip]' is known and matches the RSA host key. debug1: Found key in /Users/john/.ssh/known_hosts:2 debug1: ssh_rsa_verify: signature correct debug1: SSH2_MSG_NEWKEYS sent debug1: expecting SSH2_MSG_NEWKEYS debug1: SSH2_MSG_NEWKEYS received debug1: Roaming not allowed by server debug1: SSH2_MSG_SERVICE_REQUEST sent debug1: SSH2_MSG_SERVICE_ACCEPT received debug1: Authentications that can continue: publickey,password debug1: Next authentication method: publickey debug1: Trying private key: /Users/john/.ssh/id_rsa debug1: Offering RSA public key: /Users/john/.ssh/id_dsa debug1: Authentications that can continue: publickey,password debug1: Next authentication method: password root@[my.server.ip]'s password: Update: I have found the reason but I can't explain it yet. It is caused by uploading the key using rsync -chavz instead of scp, after I used scp to upload my key, the issue is gone. Can someone explain it? Later, I tried rsync -chv, still not working