An asymmetric public/private keypair will need to be created. This can be done using OpenSSL in Linux. The private key will be the file that ends with .key, and public key will be the file that ends with .pem.  Transfer both the public and private keys to the computer which has FileZilla Server. Follow these steps to add the public and private key to FileZilla Server:

1. Select Edit > Settings.
2. In the left panel, select SSL/TLS settings.
3. Check-mark Enable FTP over SSL/TLS (FTPS).
4. Browse and select the Private Key.
5. Browse and select the Public Key.
6. Leave password blank, do not make any other changes, and select OK.

To test this, using FileZilla Client, connect to FileZilla Server.

1. In FileZilla Client, press Ctrl S (or select File > Connect).
2. Host = IP address of our computer running FileZilla Server
3. Port = 21
4. Protocol = FTP - File Transfer Protocol
5. Encryption = Require explicit FTP over TLS
6. Connect

There should be a popup box with the Self Signed Certification details. Click OK. We can use Wireshark to prove that the data is being encrypted.