“…- Authentication factor
- Identity: An information presented by one party to another to authenticate itself. Identity-based authentication schemes can use one (or a combination) of hash, symmetric or asymmetric cryptographic algorithms.
- Context: which can be:
- Physical: Biometric information based on physical characteristics of an individual, e.g., fingerprints, hand geometry, retinal scans, etc.
- Behavioral: Biometric based on behavioral characteristics of an individual, e.g., keystroke dynamics (pattern of rhythm and timing created when a person types), gait analysis (method used to assess the way we walk or run), voice ID (voice authentication that uses voice-print), etc.
- Use of tokens
- Token-based Authentication: Authenticates a user/device based on an identification token (piece of data) created by a server such as OAuth2 protocol [65,66] or open ID [67].
- Non-Token based authentication: Involves the use of the credentials (username/password) every time there is a need to exchange data (e.g., TLS/DTLS [12,68,69]).
- Authentication procedure
- One-way authentication: In a scenario of two parties wishing to communicate with each other, only one party will authenticate itself to the other, while the other one remains unauthenticated.
- Two-way authentication: It is also called mutual authentication, in which both entities authenticate each other.
- Three-way authentication: Where a central authority authenticates the two parties and helps them to mutually authenticate themselves.
- Authentication architecture
- Distributed: Using a distributed straight authentication method between the communicating parties.
- Centralized: Using a centralized server or a trusted third party to distribute and manage the credentials used for authentication.
Whether centralized or distributed, the authentication scheme architecture can be: - Hierarchical: Utilizing a multi-level architecture to handle the authentication procedure.
- Flat: No hierarchical architecture is used to deal with the authentication procedure.
- IoT layer : Indicates the layer at which the authentication procedure is applied.
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