Summary of data encryption theory

Basic Data Encryption knowledge

InformationEncryptionThe purpose is to protect data, files, passwords, and control information on the Internet, and protect data transmitted on the Internet. data encryption techniques include data transmission encryption and data storage encryption. data transmission encryption technology is mainly used to encrypt data streams in transmission. commonly used methods include link encryption, node encryption, and end-to-end encryption.

The purpose of link encryption is to maintain the link information security between network nodes. The purpose of node encryption is to provide protection for the transmission link between the source node and the target node; end-end encryption is designed to protect data from source users to target users. among the many technologies that ensure information security, password technology is the center and key technology of information security. Through data encryption technology, the security of data transmission can be improved to a certain level, data transmission is complete.

Data Encryption Algorithm

A Data encryption system includes the encryption algorithm, plaintext, ciphertext, and key. The key controls the encryption and decryption processes. The overall security of an encryption system is based on the key instead of the algorithm, therefore, key management of the encryption system is a very important issue. the data encryption process refers to the process of converting the original digital information (plaintext) into a digital information (ciphertext) completely different from the plain text according to the encryption algorithm.

Assume that E is the encryption algorithm, and D is the decryption algorithm. The mathematical expression of data encryption and decryption is P = D (KD, E (KE, P )).

There are many types of data encryption algorithms. The standardization of cryptographic algorithms is a certain trend in the development of the information society, and is a major topic in the field of Secure Communication in various countries around the world. according to the development process, we have experienced the classical password, symmetric key password and public key password stage. The classical encryption algorithm includes replacement encryption and replacement encryption. The symmetric encryption algorithm includes DES and AES; asymmetric encryption algorithms include RSA, backpack password, McEliece password, Rabin, elliptic curve, and EIGamal algorithm. currently, DES, RSA, and PGP algorithms are the most widely used algorithms in data communication.

These encryption algorithms can be classified based on whether the keys of both sending and receiving parties are the same. in a conventional password, the recipient and the sender apply the same key, that is, the encryption key and decryption key are the same or equivalent. the advantage of the conventional password is that it has a strong confidentiality intensity, and the time test and attack, but the key must pass through the insurance Road.

In a public key password, the keys used by the recipient and the sender are not the same, and it is impossible to export the decryption key from the encryption key. the most influential public key cryptography algorithm is RSA, which can withstand all known password attacks so far. in actual use, the common password and public key password are usually used together. The DES or IDEA is used to encrypt the information, and RSA is used to transmit the session key.

For more information, see http://netsecurity.51cto.com/art/200512/13527.htm.