Server that supports security access of terminal device of the user and controlling method thereof

A server for supporting secure access to virtual machine on a public cloud comprising:

• storage unit,
• communication unit and
• controller,
• the controller is configured to:
• confirm or support to confirm whether a terminal device of a user requests a virtual machine resource through a first network meeting a predetermined security requirement;
• after an allocation of the virtual machine to the terminal device of the user and a usage authority are confirmed and an authorization token is issued, in a state where the terminal device of the user communicates with the allocated virtual machine by verifying credential to virtual machine server on the public cloud using the authorization token, confirm or support to confirm a path of a packet transmitted or received between the terminal device of the user and the allocated virtual machine;
• and
• based on determination that the packet is transmitted through a second network that does not meet the predetermined security requirement as a result of the confirmation of the path, block a session connection between the terminal device of the user and the virtual machine or control the terminal device of the user to issue a security warning on the terminal device of the user,
• wherein the controller is further configured to
• based on the security warning being issued and a feedback being not obtained for a predetermined time or longer from the terminal device of the user, block or support to block the session connection between the terminal device of the user and the virtual machine.