An Encryption Scheme with Collusion Attack Security Based on Certified Public-Key
Jia Fan · Journal of Wuhan University · 2008
Based on Gentry's certificate-based public-key encryption(CBE) scheme,which can not resist the DoS attack and the collusion attack,we propose an improved CBE scheme and give the security model,concrete algorithm and security analysis in the standard model.In the improved scheme,the user signs his own public key by a certification that is signed by a third party on the user's public key and/or his identity.Before the encryption operation,message sender should verify the signature on the receiver's own public key.Without the legal authority,the receiver would not give the right signature.So the improved scheme can resist the DoS attacks and the collusion attacks.