Concept of encryption and encryption methods

When the Internet promotes applications of various fields, data security is facing challenges. Data transmitted via computer network needs enough security, for the transmitted data may be illegal monitored, stolen, tampered or damaged at any time. It’s imperative to encrypt data in the process of transmission.
What’s data encryption?

Encryption is a technology that restricts access to data transmitted over the network. Original data (also referred to as plaintext) is coded by encryption devices (hardware or software), which is then called ciphertext. The process of restoring the ciphertext into plain text is called decryption, which is the reverse processing of encryption. But you must use the same encryption device and password to decrypt.

Encryption includes several basic functions: to prevent uninvited users to view confidential data and files; to prevent classified data being leaked or tampered; to prevent privileged users (such as system administrator) viewing private data and files; to prevent hackers easily finding out system files. Data encryption is an important mechanism to ensure computer network security. Data encryption can be divided into three ways in terms of the logical location that encryption technology is applied to:

(1) The link encryption: encryption below the network layer is called link encryption, which is mainly used to protect data transmitted between communication nodes. Encryption and decryption are both realized by password placed on the line.

(2) Node encryption: This is an improvement based on link encryption. Perform encryption on the protocol transport layer, it mainly encrypt data transmitted between source nodes and destination node, which is similar to link encryption, but its encryption algorithm should bond with encryption module that’s attached to nodes, which overcome link encryption’s shortcoming that data is easily illegally accessed at a node.

(3) End to end encryption: encryption over network layer is called end to end encryption. This is end to end encryption: encryption over the network layer called end to end encryption. It faces subjects on network layer. To encrypt data and information on application layer, it’s easy to achieve with software. Although it needs low cost, the password management is difficult. This encryption solution is applicable to the situation where information is transmitted between multiple senders and recipients in large network system.