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In order to reduce the risk of personal information leakage, it is necessary to use encryption and symmetric encryption. According to the size and security of the amount of information, screening in different schemes
Comparison of DES and AES
Since the DES algorithm was published in the world, the academic circles have carried out research and heated debates around its security. Technically, the criticism of DES mainly focuses on the following aspects:
1. As a block cipher, the encryption unit of DES is only 64 bits binary, which is too small for data transmission because each block contains only 8 characters , and some of those bits are also used for parity or other communication overhead.
2. The number of digits of the key of DES is too short, only 56 bits, and the keys used in each iteration are generated recursively. This correlation will inevitably reduce the security of the cryptosystem. The method to find the key has become feasible.
3. DES cannot resist differential and linear cryptanalysis.
4. The actual key length used by DES users is 56 bits, and the theoretical maximum encryption strength is 256. For the DES algorithm to increase the encryption strength (such as increasing the key length), the system overhead increases exponentially. Except for improving the hardware function and increasing the parallel processing function, neither the algorithm itself nor the software technology can improve the encryption strength of the DES algorithm.
Analysis of the comparison of three typical encryption algorithms of DES, AES and RSA Compared with the
DES algorithm, the AES algorithm undoubtedly solves the above problems, mainly in the following aspects:
Analysis of the comparison of the three typical encryption algorithms of DES, AES and RSA
1. The operation speed is fast. In the software and hardware with feedback mode and without feedback mode, Rijndael shows very good performance.
2. The demand for memory is very low, suitable for restricted environments.
3. Rijndael is a block iterative cipher with flexible block length and key length design.
4. The AES standard supports variable block length, the block length can be set to any multiple of 32 bits, the minimum value is 128 bits, and the maximum value is 256 bits.
5. The key length of AES is larger than that of DES, and it can also be set to any multiple of 32 bits. The minimum value is
6. 12 bits, the maximum value is 256 bits, so it is impossible to crack by exhaustive method.
7. The design strategy of the AES algorithm is WTS. WTS is proposed for differential analysis and linear analysis, and can resist differential cryptanalysis and linear cryptanalysis.
Comparison between DES and RSA
RSA algorithm has a long key and good security, but the computational complexity of encryption is large, and the encryption speed is slow, which limits its application range. In order to reduce the amount of calculation, when transmitting information, a combination of traditional encryption method and public key encryption method is often used, that is, the information is encrypted by the improved DES session key, and then the session key and the information digest are encrypted by the RSA key. After receiving the information, the other party decrypts it with a different key and can check the information digest.
Analysis of the comparison of three typical encryption algorithms of DES, AES and
RSA. The application of the combination of DES and RSA makes their advantages and disadvantages complement each other. That is, DES has a fast encryption speed and is suitable for encrypting long messages. It can be used to encrypt plaintext; RSA encryption speed is slow and security is good, and it is applied to the encryption of DES keys to solve the problem of DES key distribution.
At present, this method of combining RSA and DES has become the standard of EMAIL secure communication.