Three technologies encrypted by network data

In a regular password, the acceptor and the sender use the same key, that is, the encryption key and the decryption key are the same or equivalent. More famous routine password algorithms are: US DES and its various modifications, such as Triple DES, GDES, New DES and DES for the predecessor of Lucifer; European IDEA; Japan Fealn, Loki91, Skipjack, RC4, RC5 And classical passwords represented by transform password and runner password. The most affected in many conventional passwords is the DES password. The advantages of a routine password are strong confidentiality strength, and withstand the test and attack of the time, but its key must be transmitted through safe ways. Therefore, its key management is an important factor in system security. In the public key password, the key used by the recording party and the sender is different, and it is almost impossible to derive the decryption key from the encryption key. The more famous public key password algorithm is: RSA, backpack password, mceliece password, Diffehellman, Rabin, ONG-FiatShamir, zero-fiamsshamir, algorithm, elliptical curve, Eigamal algorithm, etc. The most influential public key password algorithm is RSA, which resists all password attacks that are known so far. The advantage of public key password is that it can accommodate the open requirements of the network, and key management issues are also simpler, especially for digital signatures and verification. However, its algorithm is complex, and the rate of encrypted data is low. Despite this, with the development of modern electronic technology and password technology, public key cryptographic algorithms will be a very promising network security encryption system. Of course, people usually use the conventional password and the public key password to be used together, such as using the DES or IDEA to encrypt information, and use RSA to pass the session key. If you are classified according to each encrypted bits, the encryption algorithm can be divided into sequence passwords and packet passwords. The former only encrypts only one bit each time, then the information sequence is first packet, and a group is processed each time. Password technology is one of the most effective technologies of network security. A encrypted network that can not only prevent unauthorized users from running eavesdropping and access, but also one of the effective methods for dealing with malware. The general data encryption can be implemented in three levels of communication: link encryption, node encryption, and end-to-end encryption. Link Encryption For a certain communication link between the two network nodes, link encryption can provide security guarantees for data transferred. For link encryption (also known online encryption), all messages are encrypted before being transferred, decrypt the messages received in each node, and then use the next link key to encrypt the message, and then transmit . A message may have to pass through the transmission of many communication links prior to reaching the destination. Since both intermediate transmission node messages are decrypted after re-encryption, all data on the links including routing information appear in ciphertext. Thus, the link encryption masks the source point and end point of the transmitted message. Due to the use of the filling technology, the fill character can be encrypted without the need to transfer data, which makes the frequency and length characteristics of the message to mask, thereby preventing analysis of the communication service. Although link encryption is quite common in a computer network environment, it is not a problem. Link encryption is typically used on a synchronous or asynchronous line of point-to-point, which requires the encryption device on the link to synchronize, and then uses a chain mode to encrypt the data transmitted on the link. This brings side effects to the performance and manageability of the network. In overseas or satellite networks that are not uncommon lines / signals, encryption devices on the link require frequent synchronization, resulting in data loss or retransmission. On the other hand, even if only a small portion of the data needs to be encrypted, all transmission data is encrypted. In a network node, link encryption only provides security on the communication link, the message exists in a clear form, so all nodes must be safe, otherwise it will leak the plaintext content. However, guarantees that the security of each node requires a high cost, providing an encrypted hardware device and a secure physical environment for each node consists of the following parts: the personal security of the node physical security, in order to ensure security strategy The cost of performing audits with the correct implementation of the program, as well as the cost of participating in insurance to prevent safety when it is destroyed. In a conventional encryption algorithm, the key for decrypting the message is the same as the key for encryption, which must be kept secret and vary by a certain rule.