In general, the key DH agreement method is used more (both in terms of calculation and bandwidth) than previous ones and requires quotas as in the case of the public key. However, it has the advantage of offering perfect forward secrecy (PFS) and flexibility in allowing implementation in several finite groups. Crypto-session (CS) is a one-way or two-way media stream. A CS is protected by a single instance of a data security protocol. Online dictionary attacks are active attacks in which the opponent tries to guess the password through successive attempts to register: the opponent does not stop intervening in the protocol, trying different passwords, and if the opposing party stops stopping, the opponent knows that he has the right password. It is clear that the draft protocol cannot prevent this attack. However, a well-designed PAKE should only have one password tested per login attempt. From that date, the application that supports the protocol must indicate the number of tests that can be tolerated before, for example, the target account closes. Key exchange protocols are designed to resolve the problem of a secret key between two or more parties, without an unauthorized party intercepting, deducing or otherwise receiving it. .B An IS-based call between two parties may be desirable for security to be established by mutual agreement or for each party to establish security for its own outflows. The first public public key memorandum of understanding  that meets the above criteria was the Diffie-Hellman key exchange, in which two parties jointly exposed a generator to random numbers, so that an earpiece cannot easily determine what the resulting value is used to create a common key. Hybrid systems use cryptography with a public key to exchange secret keys that are then used in a cryptography system with symmetrical keys.
Most practical applications of cryptography use a combination of cryptographic functions to deploy a global system that provides the four desirable functions of secure communication (confidentiality, integrity, authentication and non-contestable).