A re-random identification encryption and decryption method

Abstract

The invention discloses a re-randomized identification encryption and decryption method, aiming to solve the security defect existing in the existing re-random identification encryption and decryption method. The technical solution is: build an encryption and decryption system consisting of an initialization module, a key extraction module, an encryption module, a decryption module and a rerandom module; the key generation center runs the initialization module, generates public parameters and master private keys, and makes the public parameters public ;The key generation center runs the key extraction module, uses the receiver's identification id to generate a private key for the receiver; the sender runs the encryption module, uses the receiver's identification id to generate ciphertext C, and sends C to the public server; the public server Run the re-random module to re-randomize C, and send the new ciphertext C' to the receiver; the receiver runs the decryption module to decrypt C'. The invention can resist the replayable selected ciphertext attack based on the logo, and the operation of the re-random module does not need the logo of the receiver, which avoids the distribution of the logo.

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...

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