Public key authentication is an alternative means to identify yourself to a ftp server, instead of typing a password. It is more secure and flexible, but requires initial setup.
In conventional password authentication, the only way to that prove you know the password is to tell the server what you think the password is. This means that if the server has been hacked, or spoofed, an attacker can learn your password. Public key authentication solves this problem. A key pair is generated by our system consisting of a public key (which everybody is allowed to know) and a private key (which is kept in our secured storage). The private key is able to generate signatures. A signature created using the private key cannot be forged by anybody who does not have that key; but anybody who has the corresponding public key can verify that a particular signature is genuine. Therefore if the server is hacked or spoofed, the attacker does not gain your private key or password; they only gain one signature. And signatures cannot be re-used, so they have gained nothing.
Two roles are involved in terms of setup public key authentication for ftp steps: process designer and ftp admin.
For process designer, to setup the public key authentication, just make sure the checkbox below is checked and run the step. If the step fails, it is time to contact your ftp admin to setup the public key in the ftp server. What you will need to provide is the ftp user name used to run the step and a public key file you can download by clicking the hyperlink “Click here to download the public key file”.
For ftp admin, you need to install the received public key under the received ftp user name. Different ftp server may have different way to set it up.
Once the public key is installed in the ftp server, you could setup a ftp step connect to the server without password any more. Just by clicking the “Use public key authentication” checkbox.