Authenticable agent re-encryption system and method based on symmetric cryptography

Abstract

The invention discloses an authenticable agent re-encryption system and method based on symmetric cryptography. The system is composed of a client and an agent. The client is used to initiate a re-encryption request to the agent, and comprises a random number generator, a key generation module, an encryption module, a decryption module and a key update module. The agent is mainly composed of a re-encryption module and re-encrypts data. Each module performs the corresponding operation to produce the corresponding output. The system does not use a public key encryption system but uses symmetric cryptography, which greatly improves the processing speed. A pseudo-random function PRF in the encryption system is generated by using Ring-LWR, SHA1 and SHA256 methods, and has the property of homomorphism. The system realizes agent re-encryption and message integrity authentication to verify whether a message is maliciously tampered.

Description

Technical field [0001] The present invention relates to the technical field of information security, in particular to an authenticating proxy re-encryption system and method based on symmetric cryptography. Background technique [0002] Cryptography is the core and foundation of information security and is widely used in network communications, e-commerce, banking, national defense and military fields. Cryptography includes symmetric cryptography and asymmetric cryptography. Asymmetric cryptography is also called public key cryptography. [0003] In the current cloud service model, users store encrypted data in unreliable cloud servers. Due to security policies or information sharing, data encryption keys may need to be changed frequently. The traditional scheme is to retrieve the data from the cloud server and decrypt it with the original key, then encrypt it with the new key and send it back to the cloud server. However, this solution is obviously inefficient and not scalable....

AI Technical Summary

Problems solved by technology

[0005] The traditional proxy re-encryption scheme uses the public key cryptography system. Its obvious disadvantages are the large amount of calculation and the slow encryption speed, which cannot meet the needs of today's big data era, and its practicability is greatly reduced.

Moreover, the current proxy re-encryption scheme cannot verify the reliability of the message, and cannot guarantee that the message will not be maliciously tampered with, which also poses a great threat to security.

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