# A Survey of Internet of Things (IoT) Authentication Schemes +
## 5 Analysis of IoT Authentication Schemes
### Wireless Sensor Networks  
Wireless Sensor Networks (WSN) is the ability to add the connectivity and sensing features to billions of sensors embedded in various fields (appliances at homes, vehicles, grids, etc.). The authors of [108] proposed an authentication protocol at the media access control sub-layer called Optimization of Communication for Ad-hoc Reliable Industrial networks (OCARI), in which they used a one-time shared session key. This technique is suitable for resource-constrained devices. Blom key predistribution scheme [109] and the polynomial schema [110] are considered as appropriate to be used as key management protocols for some IoT use cases. The authors of [111] proposed an improved user authentication and key management protocol for WSNs using Bio-hashing [112]. The use of the BAN-logic ( logic of belief and action that ensures one part of communication believes that the key in authentication is good) ensures mutual authentication. The authors of [113; 114] proposed a mutual authentication which consists of two stages: in the enrollment stage, every node should be identified within the system, and in the authentication stage, a number of handshake messages are exchanged between the end device and the server, which result is a session key to be used for upcoming communication. The authors of [115] developed a group authentication technique in wireless networks for achieving both mutual authentication and privacy. An end node will have the ability to move between access points without the need for re-authentication every time. All the roaming group members information are transmitted to the Base Station (BS) the first time a Mobile Station (MS) is authenticated. Then, the MS sends the information to the group manager, which aggregates all the information and sends it back to the BS. The BS sends it to the access service network for verifying the authentication. After analyzing some existing chaotic-maps based protocols, the authors of [116] provided a chaotic maps-based mutual authentication in WSN. In [117], the authors proposed a lightweight authentication scheme with anonymous features by providing hop-by-hop authentication and un-traceability. The main contribution is the achievement of user privacy in WSN. In [118], the authors provided an authentication protocol for WSN, which can guarantee different security features such as the privacy of the user, un-traceability,backward secrecy, and strong forward secrecy. It is also resilient to node capture and key compromise impersonation attack. To ensure mutual authentication between the user, the end node, and the gateway node (GWN) in a WSN, the authors of [119] developed an authentication scheme based on lightweight Hash and XOR operations that gives the remote user the ability to connect to the end nodes in WSN systems without the need to be connected at the beginning to the gateway. Due to the resource-constrained features of the sensor nodes in WSN systems, there is a need for lightweight encryption protocols. Thus, the authors of [120] proposed a secure authentication protocol for WSN based on Elliptic Curve Cryptography (ECC) which is considered lightweight compared to the traditional RSA cipher. Besides, the authors applied Attribute-Based Access Control (ABAC) authorization mechanism for access control, which is considered scalable. In [121], the authors proposed an authentication scheme to be deployed in WSNs. The scheme consists of two main steps: the initialization step in which the user is given a public/private key using a lightweight ECC-based protocol. The second step is the authentication step in which two nodes will use the public/private pair to mutually authenticate each other. The authors of [122] provided a protocol called E-SAP for Efficient-Strong Authentication Protocol for wireless health care applications.