Encryption and decryption method, device and terminal

Abstract

Embodiments of the present invention relate to the technical field of communications, and provide encryption and decryption methods and devices, for a user to perform real-time deletion, insertion, and modification on previously input information. The method comprises: receiving i input plaintexts, i≥1; encrypting each of the i plaintexts based on a master key according to the input sequence of the plaintexts to obtain a first ciphertext sequence and first position information, the first ciphertext sequence comprising i ciphertexts corresponding to the i plaintexts, the first position information comprises position indication information and input indication information of each of the i ciphertexts, the position indication information being used for indicating the positions of the ciphertexts in the first ciphertext sequence, and the input indication information being used for indicating the input sequence of the plaintexts corresponding to the ciphertexts; if an editing operation to the input plaintexts is detected, modifying the first ciphertext sequence and the first position information based on the editing operation to obtain a second ciphertext sequence and second position information; and sending the second ciphertext sequence and second position information.

Description

technical field [0001] The present invention relates to the field of communication technology, in particular to an encryption and decryption method and device. Background technique [0002] When a user uses a terminal to log in to a third-party application, he needs to enter key information such as account number and password through the input method. If the input method is intercepted by a Trojan horse virus during the process of sending the input information to the third-party application, the input account and password will be blocked. Passwords and other information are stolen by malicious programs. Therefore, it is necessary to protect the input method to prevent the input information from being stolen. [0003] At present, conventional encryption and decryption algorithms are usually used to protect the security of the input method. For the information entered by the user, that is, the plain text, the input method uses a conventional encryption algorithm to encrypt the...

AI Technical Summary

Problems solved by technology

When the input method uses a stream cipher algorithm for encryption, such as RC4, this algorithm encrypts the continuous plaintext sequence by byte or by bit, and its advantage is that it can reduce the overhead of ciphertext transmission and eliminate the length extension of ciphertext, but , because the algorithm encrypts consecutive bytes or bits, if it is necessary to insert, modify, or delete encrypted information, the encryption of the entire sequence input before will be invalidated, so it cannot satisfy the user's input requirements. Information needs to be inserted, modified and deleted in real time

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