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. The original and still most famous protocol for the key agreement was proposed by Diffie and Hellman (see the key agreement Diffie Hellman) as well as their concept of cryptography with public keys. Basically, Alice and Bob users send key public values through an uncertain channel. Based on the knowledge of the corresponding private keys, they are able to correctly and safely calculate a common key value. An earpiece, however, is not capable of this key with only the knowledge of… 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. Key mous that is verified by the password requires the separate implementation of a password (which may be smaller than a key) in a way that is both private and integrity. These are designed to withstand man-in-the-middle and other active attacks on the password and established keys. For example, DH-EKE, SPEKE and SRP are Diffie-Hellman password authentication variants. A large number of cryptographic authentication schemes and protocols have been designed to provide authenticated key agreements to prevent man-in-the-middle and related attacks.
These methods typically link the mathematically agreed key to other agreed data, such as this: A common method for key tuning is asymmetric encryption: Alice generates a K key for an algorithm (z.B. a 128-bit random sequence), then the crypt with Bob`s public key and sends the result to Bob. Bob decrypts it (with his private key) and receives a copy of K. At the end of the day, Alice and Bob know the same secret key K, so it`s an important deal. If we look at the details, we see that the key chord begins with a key realization entirely made by Alice. This « local-generation-then-asymetric-encryption » method is how most SSL connections are made over the Internet; Note that Diffie-Hellman cannot be described in this way, so don`t expect all important agreements to work that way.