Encryption and decryption method and device in multicast communication

Abstract

The embodiment of this specification provides an encryption and decryption method and device in multicast communication. The encryption method is performed by the message sender, including generating a random number k in a finite field, and performing k times multiplication on the base point of the curve in the elliptic curve on the finite field to obtain the encryption point R, and determine the symmetric key based on its abscissa key sk. Then, use the symmetric key sk to encrypt the message plaintext m with a symmetric encryption algorithm to generate the message ciphertext C. On the other hand, obtain the respective public keys Qi of the w selected receivers, use the random number k to perform multiplication operations on the points on the elliptic curve corresponding to each public key Qi, and generate the corresponding secret key ciphertext Ki. Generate an encrypted message based on at least the message ciphertext C and w key ciphertexts, and broadcast it. The specified recipient can use the multiplicative inverse of its private key di in the finite field to perform multiplication operations on the secret key ciphertext to restore the encryption point, and then restore the symmetric secret key sk to decrypt the ciphertext C.

Description

technical field [0001] One or more embodiments of this specification relate to the field of data security, and in particular to methods and devices for encryption and decryption in multicast communication. Background technique [0002] With the development of computer technology, data security has become an important issue. In many scenarios, data transmission needs to be carried out in non-secure channels. At this time, data encryption becomes a guarantee of data security. For example, as a decentralized and trustless network, the blockchain network maintains distributed ledgers jointly by multiple nodes that do not need to reach mutual trust. In the process of recording transactions and forming blocks, a large amount of data will be transmitted between nodes in the form of point-to-point transmission. In order to ensure the authenticity of data, digital signatures are often used to prevent tampering during data transmission. For the data of certain content, it is only h...

AI Technical Summary

Problems solved by technology

Although there are already some encryption and decryption algorithms, these algorithms are often relatively complex, and will generate a lot of computing overhead in the case of broadcast or multicast, affecting transmission efficiency

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