Rerandomizable identifier encryption and decryption method

Abstract

The invention discloses a rerandomizable identifier encryption and decryption method, and aims to solve the security defect of an existing rerandomizable identifier encryption and decryption method. According to the invention, the technical scheme is that the method comprises the steps: constructing an encryption and decryption system composed of an initialization module, a key extraction module,an encryption module, a decryption module and a re-random module; enabling the key generation center to operate the initialization module, generating a public parameter and a main private key, and disclosing the public parameter; enabling the key generation center to operate a key extraction module, and generating a private key for the receiver by adopting the identifier id of the receiver; enabling a sender to operate the encryption module, generating a ciphertext C by adopting the identifier id of the receiver, and sending the ciphertext C to the public server; enabling a public server to operate a re-randomization module to re-randomize the C, and sending the new ciphertext C' to a receiver; and enabling a receiver to operate the decryption module to decrypt the C'. According to the invention, the replayable selective ciphertext attack based on the identifier can be resisted, and the operation of the rerandom module does not need the identifier of a receiver, so the distribution ofthe identifier is avoided.

Description

technical field [0001] The invention belongs to the technical field of information security, relates to an identification encryption and decryption method, in particular to a re-random identification encryption and decryption method with high security. Background technique [0002] At present, representative re-random identification encryption and decryption methods in the field of encryption include BB04 method, Waters05 method and Gentry06 method. However, these three methods can only achieve identity-resistant chosen plaintext security (ID-CPA security). In practical applications, some attackers with stronger capabilities can crack the secure encryption and decryption method of ID-CPA. The following will take the Gentry06 method as an example to illustrate. [0003] Gentry06 method: proposed by Gentry in the 2006 EuroCrypt conference. Specifically include the following steps: [0004] In the first step, the key generation center (referring to the server responsible fo...

AI Technical Summary

Problems solved by technology

[0027] So far, there is no published literature related to a re-randomized identity encryption and decryption method that can resist the above attack (also known as identity-based replayable chosen ciphertext attack)

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