For example, Secure snmp and SNMPv2 compute cryptographic MD5 checksum of shared secret for a block of data and information that must be authenticated Rivest92, GM93. This serves to In order to authenticate the source of the data it is assumed that this amount is extremely difficult to falsify. She did not mention the fact that they themselves sent data is valid, but only that they are sent exactly the data sender. Cryptographic checksums can be used to get on the effective authentication, and are particularly useful in the exchange of computer-computer. The main difficulty of implementation – the transfer of keys. 4.4. Digital signature (signature) digital signature is a cryptographic mechanism that is analogous to a handwritten signature. It serves to authenticate the data block, and confirms that it received from the sender.
A digital signature using asymmetric cryptography (public keys) may be useful to determine the source of messages even if the sender denies authorship. Digital signature provides authentication without confidentiality, as the text of the message is not encrypted. A digital signature is used in a system of confidential mail pem (Privacy Enhanced Mail) Linn93, Kent93, Balenson93, Kaliski93. 5. User authentication on a computer there many different approaches to user authentication on remote computer. There are two threats when accessing remote computers. First, an attacker can intercept the user id and password, and later use them in an attack 'play'. Secondly, the form of a password allows an attacker to try to guess. Currently, most systems use plain text to send passwords over the network channels that greatly simplifies the interception Anderson84, Kantor91.