So I am setting up a connection between my machine [fedora 17] and a virtual machine running in Virtual Box in which is running CentOS 5. I have installed openssh from the repositories on CentOS, and I have configured everything as it follows: Protocol 2 HostKey /etc/ssh/ssh_host_rsa_key HostKey /etc/ssh/ssh_host_dsa_key SyslogFacility AUTHPRIV PermitRootLogin yes RSAAuthentication yes PubkeyAuthentication yes AuthorizedKeysFile /home/pigreco/.ssh/authorized_keys PasswordAuthentication no ChallengeResponseAuthentication yes GSSAPIAuthentication yes GSSAPICleanupCredentials yes UsePAM yes AcceptEnv LANG LC_CTYPE LC_NUMERIC LC_TIME LC_COLLATE LC_MONETARY LC_MESSAGES AcceptEnv LC_PAPER LC_NAME LC_ADDRESS LC_TELEPHONE LC_MEASUREMENT AcceptEnv LC_IDENTIFICATION LC_ALL LANGUAGE AcceptEnv XMODIFIERS X11Forwarding yes Subsystem sftp /usr/libexec/openssh/sftp-server this is the configuration file sshd_config on the server i.e. on the CentOS. Moreover I have created a public/private key pair as usual on the .ssh/ folder in my home directory in my OS, i.e. Fedora, and then I've copied with scp the id_rsa.pub to the server and then I have appended its content to the file .ssh/authorized_keys on the server machine. The error that I get is the following: OpenSSH_5.9p1, OpenSSL 1.0.0j-fips 10 May 2012 debug1: Reading configuration data /etc/ssh/ssh_config debug1: /etc/ssh/ssh_config line 50: Applying options for * debug1: Connecting to 192.168.100.13 [192.168.100.13] port 22. debug1: Connection established. debug1: identity file /home/mayhem/.ssh/identity type -1 debug1: identity file /home/mayhem/.ssh/identity-cert type -1 debug1: identity file /home/mayhem/.ssh/id_rsa type 1 debug1: identity file /home/mayhem/.ssh/id_rsa-cert type -1 debug1: identity file /home/mayhem/.ssh/id_dsa type -1 debug1: identity file /home/mayhem/.ssh/id_dsa-cert type -1 debug1: Remote protocol version 2.0, remote software version OpenSSH_5.3 debug1: match: OpenSSH_5.3 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 16:e5:72:d1:37:94:1b:5e:3d:3a:e5:da:6f:df:0c:08 debug1: Host '192.168.100.13' is known and matches the RSA host key. debug1: Found key in /home/mayhem/.ssh/known_hosts:1 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,gssapi-keyex,gssapi-with-mic,keyboard-interactive debug1: Next authentication method: gssapi-keyex debug1: No valid Key exchange context debug1: Next authentication method: gssapi-with-mic debug1: Unspecified GSS failure. Minor code may provide more information Cannot determine realm for numeric host address debug1: Unspecified GSS failure. Minor code may provide more information Cannot determine realm for numeric host address debug1: Unspecified GSS failure. Minor code may provide more information debug1: Unspecified GSS failure. Minor code may provide more information Cannot determine realm for numeric host address debug1: Next authentication method: publickey debug1: Offering RSA public key: /home/mayhem/.ssh/id_rsa debug1: Server accepts key: pkalg ssh-rsa blen 279 Agent admitted failure to sign using the key. debug1: Trying private key: /home/mayhem/.ssh/identity debug1: Trying private key: /home/mayhem/.ssh/id_dsa debug1: Next authentication method: keyboard-interactive Do you have some good suggestion of what I can do? thank you