Encryption and decryption method and terminal based on network transmission data packet

Abstract

The present application discloses a method for encrypting and decrypting data packets based on network transmission and a terminal. Using the end-to-end real-time encryption method based on the stream cipher algorithm, the communication parties negotiate the session parameters and establish the password table respectively in the session initialization phase. The sender extracts the header information of the data packet to generate the starting point of the key stream, and generates a section of the key stream according to the cipher table and the starting point to XOR the encrypted data packet payload. The receiver judges whether there is a network packet loss based on the header information of the data packet. When there is a packet loss, the receiver first completes the synchronization of the password table, and then generates a synchronized key based on the updated password table and the starting point to decrypt the data packet payload. This application realizes the real-time encryption technology with key self-synchronization function under the network condition of packet loss without additional increase of network communication traffic and online real-time key stream generation.

Description

technical field [0001] The present application relates to the field of secure network communication, in particular to a method for encrypting and decrypting data packets based on network transmission and a terminal. Background technique [0002] The Internet network has been widely used in the communication field because of its simplicity, cheapness and openness. For example, VoIP (Voice over Internet Protocol) is a new communication technology that uses the Internet to spread voice packets. However, due to the openness of the Internet and its own insecurity, network transmission data has more insecure factors than traditional technologies such as voice communication based on circuit switching. In order to ensure the security of voice, video, image and / or text transmission in an open network, the most common technology is to encrypt the transmission of data packets. However, encrypting the data packets additionally increases the communication delay, which is especially a gr...

AI Technical Summary

Problems solved by technology

The disadvantage of this method is that both parties need to establish a fixed key table in advance, and the key table should be large enough to ensure the randomness of the key, which consumes a lot of memory resources, especially for mobile terminal equipment. ;This method increases the data transmitted in the network in order to ensure the encryption and decryption keys are synchronized, and additionally adds random numbers and random data of the remainder length; in addition, this method is difficult to effectively define the random number and the random data of the added remainder length

The disadvantage of this method is that simply connecting both parties to a synchronization signal source to achieve key synchronization is difficult to achieve in reality, and large-scale system expansion cannot be performed; adding a fixed constant bit to determine whether synchronization brings new Security risks

The disadvantage of this method is that it is difficult to fully guarantee that the keys distributed by the first network entity can be received by the second network entity in practical applications. When some keys distributed by the first communication entity cannot be received by the second communication entity , the key tables of both communication parties will be out of synchronization, and this method will not be implemented correctly, so this method does not really realize the key synchronization function; additional network traffic

The disadvantage of this method is that both parties need to establish a fixed key mapping table in advance, which also faces a huge resource consumption problem; both parties need to always maintain a secure clock for synchronization, which is often difficult to achieve in practical applications ; This method needs to periodically send a synchronous control frame containing a key index, which increases additional network communication traffic

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