Method and system for sequencing ciphertexts orienting to homomorphic encryption

Abstract

The invention discloses a method and a system for sequencing ciphertexts orienting to homomorphic encryption. The system comprises the following three parties: a client side, a storage server and an agency, wherein the storage server and the agency cannot mutually collude. The method comprises the following steps: an SH. Keygen secret key generation operation is adopted by the client side to generate a pk (public key) and a sk (secret key); the sk is sent to an agency server by the client side; data are encrypted, and are mandated to the storage server by the client side; a sequencing command is sent to the storage server by the client side; homomorphic subtraction operation is carried out on the ciphertexts need to be ranked by the storage server, so as to obtain the ciphertext csub which is equal to SH. Sub (pk, c1, c2); the ciphertext csub is sent to the agency server; the ciphertext csub is decrypted through the agency server by utilizing the sk, so as to obtain a plaintext sub which is equal to SH. Dec (sk, csub); the sub is compared with 0 to determine the sequence of the plaintext; the result is encrypted to be sent to the client side through the storage server; and after the result is decrypted through the client side, so as to obtain the sequence of the plaintext corresponding to the ciphertext, no plaintexts are leaked in the whole process; although the difference of the plaintexts is obtained through the agency server, the plaintexts corresponding to the difference cannot be calculated; and the whole process is safe.

Description

technical field [0001] The invention relates to the fields of multi-party computing and cryptography, in particular to a homomorphic encryption-oriented ciphertext sequencing method and system. Background technique [0002] As a new technology emerging in recent years, the Internet of Things includes four core technologies: RFID technology, sensor technology, communication technology and cloud computing technology. When everything is related to the network, the Internet of Things will inevitably generate massive data, so traditional hardware architecture servers will find it difficult to meet data management and processing requirements, and must rely on cloud computing. However, under normal circumstances, it is impossible for massive data to be held by the owner, but to entrust a specialized data storage service organization to store it. At the same time, the computing process of cloud computing itself does not happen on the client side, but on the server side. All of thi...

AI Technical Summary

Problems solved by technology

The main disadvantages are: encryption introduces random noise, so the obtained ciphertext is a random ciphertext, and the ciphertext cannot be directly compared in size, and the order of the ciphertext cannot be determined, so many calculations cannot be supported, such as sorting, query, etc.

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