# Key Agreement and Authentication Protocols in the Internet of Things: A Survey
## 3 Security Protocols for the Internet of Things
The proposed protocols can support the authentication process of the IoT device network, which consists of both typical devices designed to control the vital functions of patients and autonomous vehicles and drones. A characteristic feature of both solutions is their short signature size. Moreover, the authors showed that both schemes are characterized by low communication and computing costs compared to similar solutions. The authors confirmed that the proposed protocolsmeet the assumptions of the ROM and protect patient privacy, and ensure data integrity and authenticity. [PERSON] et al. in [82] have proposed an authentication protocol for medical IoT solutions. The proposed protocol is based on blockchain [83] and fog calculations, Ethereum-powered smart contracts [84], PUF, and biometrics. Blockchain and fog technology ensure nonrepudiation, transparency, low latency, and efficient bandwidth use. Other technologies are used to prevent replay, spoofing, and cloning attacks. The authors checked and confirmed the protocol's security by using the Scyther tool. Moreover, they compared their protocol with similar computation costs and performance solutions. The authors showed that the proposed protocol could be successfully used in healthcare networks that use devices with limited resources. [PERSON] et al. in [85] also addressed medical safety issues. The authors focused on solutions for telecare medicine information systems [86]. They proposed an authentication protocol that uses hash functions, random functions, radio frequency identification (RFID) technology [87], and bitwise logical operations [88]. They checked the correctness and security of the proposed protocol with the help of BAN and GNY logics and Avispa and Scyther tools. These studies have shown that the protocol is resistant to typical attacks occurring in IoT networks and meets the most crucial security properties. However, [PERSON] et al. in [89] have reexamined the protocol apportioned by [PERSON] et al. in [85]. The authors showed that despite the use of hashing functions that reduce computing costs of endpoint devices, storage and communication costs are higher. Consequently, there may be delays in the transmission of medical data. Moreover, they have shown that this protocol is susceptible to impersonation, insider, stolen smart card, MITM, and modification attacks. Furthermore, the protocol does not include the possibility of changing the password, which significantly affects the security of data transmission. [PERSON] et al. in [90] proposed a protocol for medical IoT that protects patient data from illegal access by unauthorized servers. The authors created an encryption method for this protocol based on cyclic shift and XOR operation. Thanks to it, the protocol maintains the safety of users but does not burden devices. The authors demonstrated the security of the proposed protocol by using the BAN logic. Moreover, they have shown that the protocol is resistant to typical attacks in IoT environments. The authors also compared their protocol with similar solutions and obtained satisfactory results in achieving safety attributes and energy consumption during communication and calculations. [PERSON] et al. in [91] focused on IoT solutions in the healthcare field. The authors designed a protocol by using the AES [92] and blowfish [93] algorithms to encrypt medical data, the Koblitz method to choose the embedding points [94] curve, and hyperelliptic curve [95] for embedding medical data in a medical image. The embedded image prepared in this way is then compressed with a five-level discrete wavelet transform file to achieve a reasonable payload. The authors confirmed the proposed method's correctness, especially in medical image processing. Moreover, they suggested that the protocol could be used in real-time applications. [PERSON] et al. in [96] introduced the LAP-IoHT protocol, a three-factor authentication protocol designed for health-related IoT solutions. Authentication is based on using the smart card, passwords, and biometric features.