Hash ciphertext re-encryption method based on noise and decryption method after re-encryption

Abstract

The invention discloses a Hash ciphertext re-encryption method based on noise and a decryption method after re-encryption. The re-encryption method comprises the steps of 1 setting a static strategy; 2 setting a dynamic strategy and selecting the static strategy; 3 dividing original Hash ciphertext into first front half Hash ciphertext and first rear half Hash ciphertext; 4 forming second front half Hash ciphertext or second rear half Hash ciphertext; 5 randomly generating a noise character string; 6 forming first rear half Hash ciphertext with noise or second rear half Hash ciphertext with noise; 7 generating first re-encrypted noise ciphertext or second re-encrypted noise ciphertext. The decryption method comprises the steps of 1 obtaining a first noise inserting position; 2 obtaining a second noise inserting position and the length of the noise character string; 3 forming the first rear half Hash ciphertext with noise; 4 forming first rear half Hash ciphertext; 5 generating decrypted original Hash ciphertext. The safety of the original Hash ciphertext can be improved, and the expenditure is low.

Description

technical field [0001] The invention belongs to the technical field of encryption, and in particular relates to a noise-based hash ciphertext re-encryption method and a decryption method after re-encryption. Background technique [0002] Existing techniques for encrypting user names include encryption methods such as MD5 and SHA. The main method of MD5 encryption is to hash and encrypt the user's plaintext to form ciphertext, and then store the ciphertext in the database. When the user logs in later, convert the password entered by the user into an MD5 code and compare it with the ciphertext stored in the database. Yes, the judgment is consistent. Although the 128-bit large integer of the password encrypted by MD5 cannot be decrypted mathematically, in other words, even if you see the source program and algorithm description, you cannot convert an MD5 value back to the original string, from Mathematically speaking, it is because there are infinitely many original strings, ...

AI Technical Summary

Problems solved by technology

In addition, the existing technology encrypts the plaintext of the user to obtain the ciphertext. If the ciphertext is encrypted again, although the encryption strength of the ciphertext can be improved, the encryption and decryption overhead will be greatly increased.

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