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. This protocol is subject to a dictionary attack: an earpiece can simply record the first message (gx, h, IDA) and test the candidate tags pwa vs. h. If the opponent receives pwa h-H (pw,gx,IDA,IDB) for a given value, it is very likely that he has found the password. Note that the password never appears directly in the protocol. Bridge: The gateway is used to transmit the RTP (Real-Time Transport Protocol) stream and helps the service provider collect the monitored RTP stream for legal interception. . B A SIP-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. Key exchange protocols allow two or more parties to set up a shared encryption key that allows them to encrypt or sign data they want to exchange.
Key exchange protocols typically use cryptography to achieve this goal. To achieve this goal, different cryptographic techniques can be used. Tunneling. MikeY could be included in the minutes of the meeting (z.B. SDP and RTSP) on “tunnels”. We have already mentioned that offline dictionary attacks have an impact on authentication; Now back to that. As explained above, a PAKE protocol cannot leak a single bit of password information. This means that no mechanism can be available to ensure that the correct password is used by the other party directly at both ends of the protocol. For example, the password cannot fill out an equation that can be verifiable effectively, which is, by chance, the error of the dummy protocol in fig. e49.5.C`s exactly how a digital signature scheme works, and the decisive difference is that the long-term secret is cryptographically strong. That`s the method behind STS. Although far from the only useful key exchange protocol, the Diffie-Hellman (D-H) protocol is used in a number of systems.
D-H allows both parties to exchange an exchange (Bob and Alice) to provide some of the secret key. This is such that the entire key is not sent through the unsecured channel. Thus, a snoop will not receive the information necessary to steal the secret key. The minutes are as follows. Figure e49.5. Password authentication protocol. In the classic key exchange, the exhaustive search for the right long-term key simply cannot be made possible by construction: it is totally random and very long. On the other hand, a password is probably short and is created from a small set of values with a coincidence less than the ideal, which allows an exhaustive search. We illustrate the impact of this phenomenon with a “stupid” protocol. In cryptography, a key memorandum of understanding is a protocol in which two or more parties can agree on a key so that both influence the outcome. If this is done correctly, it prevents undesirable third parties from imposing an important decision on the appropriate parties. Protocols that are useful in practice also do not reveal to a listening party the key that has been agreed upon.
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.