Electronic User Authentication Key for Access to HMI/SCADA via Unsecured Internet Networks

Table 3

Alternative authentication methods.

Method	Description
Biometrics [28, 29]	These are unique biological and physiological characteristics that make it possible to establish a person’s identity. There are five most common types of biometrics: fingerprint, facial, voice, eye iris, and palm and finger vein patterns.
Single sign-on (SSO) [30, 31]	An authentication method that allows users to securely authenticate to multiple applications and sites at once using a single set of credentials.
OpenID Connect (OIDC) [32, 33]	Describes a metadata document RFC that contains most of the information needed for any application to sign in. This includes information such as the used URLs and the location of the service signing public keys.
One-time password (OTP) [34, 35]	It is a password that is valid for only one authentication session. The one-time password can also be limited to a certain period of time. The advantage of a one-time password over a static password is that the password cannot be reused. Thus, an attacker who intercepted data from a successful authentication session cannot use the copied password to gain access to the protected information system.