# What Is Key Agreement Scheme

We compare and analyze the two systems and show that they meet the security requirements of Section 3. In Diagram 1, the Ellips-Diffie-Hellman (ECDH) algorithm is used using a public key restored by an implicit certificate to solve certain problems. The equation (6) shows that the DS is generated by a key agreement based on the ECDH, which can only calculate A and B. It is possible to generate a KDS which, in turn, generates a session key (via the KDF key bypass function) by entering IDA, IDB and rA,rB; These are the random positive identifiers and whole numbers (Nonces) used to create the DS and set up the session. The only entities they can calculate are A and B, and mutual authentication is ensured by the calculation of KDS. Entities registered in the certification body perform mutual authentication using their implicit certificates for the installation of session keys to ensure secure communication. they agree on a session key. During this process, a key bypass function is used to prevent reading and spoofing attacks to which traditional patterns are exposed. Below is described the AKA which allows A to communicate safely with B. In an important agreement, both sides contribute to the negotiation of common secrecy. Examples of important agreements are Diffie-Hellman (DHKE) and Elliptic-Curve Diffie-Hellman (ECDH). Many cryptographic algorithms exist for key exchange and key device.

Some use cryptographic systems with a public key, others use simple key exchange schemes (such as Diffie-Hellman Key Exchange), others include server authentication, others include customer authentication, some use passwords, some use digital certificates or other authentication mechanisms. Challa et al. [20] proposed in 2018 an AKA system for the cloud-based cyber-physical system (CPS). The authors of [20] have proposed a secure protocol for CPS environments such as Smart Grid via a trusted instance, but a user masking attack is possible because the cloud server does not verify the validity of the authentication requirement. In addition, there is a problem that communication can be performed without generating a session key. Usually, the problem of the hellman chain on the Galis field (CDHP) and the same problem for elliptical curves (eCDHP) are, because of their hardness, the most popular elements for many authenticated key chord schemes [4-8, 10-19]. However, modular exposure calculations on the Galis field or the multiplication of points on elliptical curves represent a significant computational load for customers, for whom either their computing capacity or their batteries are limited. These customers are called light customers in the rest of this document. Even a key Native D-H diagram (without authentication of the communicating parts) that uses the cdHP requires two modular exposures from each part, and the corresponding version on the elliptical curves would require two point multiplications of each part. In general, an authenticated version of the key D-H diagram or an advanced version of the key D-H diagram that protects customer anonymity would require more modular exposures or more point multiplications [9-12, 14-16, 20]. Therefore, it is important to reduce the number of exposure/point multiplication calculations for these thin clients.

In 2014, Chien [4] formulated the modified D-H computer problem (MCDHP) and proposed an authenticated D-H key agreement system using MCDHP. The system [4] did reduce the number of modular exposures, but did not protect the client`s anonymity. By designing key exchange schemes, cryptographic keys exchange securely between two parties, so that no one else can get a copy of the keys. Usually, at the beginning of an encrypted conversation (z.B.