When a user transmits the data from/to the platform, all data is encrypted using an HTTPS connection.
What does it mean?
The data sent (and received) to the webpage of the platform is encrypted by a commonly used so-called RSA algorithm which makes it impossible for unauthorized people to see what is being transferred.
How to check if truly this happens?
Go to the webpage of the platform in your browser, click on the little padlock icon and see the connection details (more information) here. Under security you can check the privacy and the technical details (with Firefox). With Chrome after you clicked on the locker icon, you can see the details under 'Certificate'.
Every browser has to provide information about the encryption of a webpage.