ssh登录提示The authenticity of host '192.168.68.xx (192.168.68.xx)' can't be established

ssh登录提示The authenticity of host ‘192.168.68.xx (192.168.68.xx)’ can’t be established.

xshell命令行输入ssh 192.168.68.xx，提示：
The authenticity of host ‘192.168.68.xx (192.168.68.xx)’ can’t be established.
ECDSA key fingerprint is c8:16:22:4f:b1:72:4f:39:01:d8:47:82:40:10:ec:b2.
意思是：192.168.68.xx主机的可信度不能确定
Are you sure you want to continue connecting (yes/no)?
输入yes，提示;
Warning: Permanently added ‘192.168.68.13’ (ECDSA) to the list of known hosts.
接下来提示输入password：
输入密码既可登录。