vsftpd FTP server supports secure connections via SSL / TLS, same encryption used with online banking and shopping. This applies to the control connection (including login) and also data connections. You will need a ftp client with SSL support too.
OpenSSL is a cryptography toolkit implementing the Secure Sockets Layer (SSL v2/v3) and Transport Layer Security (TLS v1) network protocols and related cryptography standards required by them. It also includes the openssl command, which provides a rich variety of commands You can use the same command to debug problems with SSL certificates. To test the [...]