This makes these machines "servers" and not working stations. This shared secret code can then be used to encrypt all exchanges between machines, providing secure transmission of authentication information kdc. Finally, the workstations that are remotely available, may use an asymmetric encryption technology to encrypt communications. Public key workstation will be available to all customers. The user can use public key to encrypt the password and the remote system decrypts it and authenticates the user without the threat of disclosure of the password in transit.
The limitation of this system security-oriented workstation lies in the fact that it does not authenticate individual users, and only the individual workstations. In some environments, such as multi-level government security systems needed user-user authentication. 6. Distribution of keys and control keys for access control is the most serious problem faced in providing authentication in large networks Internet. Needham-Schroeder protocol NS78, NS87, which is used in the system Kerberos, based on a centralized key server. In large enterprise networks require a significant number of key servers, at least one key server for each administrative domain. There is also a need for mechanisms for selected key servers needed to coordinate the generation of session keys of participants in different administrative domains. Most encryption algorithms using public keys require a very large computing power and therefore are not ideal for encrypting packets on a network. However, the asymmetric property makes them very useful at the beginning of the session for the symmetric session key. In practice, the commercial sector probably uses asymmetric algorithm for digital signatures and send the keys, but not for the mass data encryption.