What cybersecurity measure is critical for preventing unauthorized access to a hydro plant's SCADA system from a remote location?

Implementing multi-factor authentication (MFA) is a critical cybersecurity measure for preventing unauthorized access to a hydro plant's SCADA system from a remote location. A SCADA (Supervisory Control and Data Acquisition) system controls and monitors the plant's equipment. Remote access to this system is often necessary for legitimate operators and engineers to perform maintenance or respond to emergencies from off-site. However, without proper security, remote access points can be exploited by malicious actors. Multi-factor authentication requires users to provide multiple independent verification factors to prove their identity before being granted access. These factors typically include something the user knows (e.g., a password), something the user has (e.g., a security token or smartphone app), and something the user is (e.g., a biometric scan). Even if an attacker manages to compromise one factor, such as a password, they would still need to bypass the other factors to gain unauthorized access. For example, requiring a password and a one-time code generated by a mobile app significantly reduces the risk of unauthorized entry compared to relying solely on a password. MFA provides a robust layer of defense, making it much more difficult for attackers to compromise the SCADA system and potentially disrupt plant operations.