In this paper, a novel proxy re-encryption (PRE) scheme with keyword search is proposed, where only the ciphertext containing the keyword set by the delegator can be transformed by the semi-trusted proxy and then decrypted by delegatee. In the proposed scheme, the semi-trusted proxy can convert the ciphertext encrypted under the delegator’s public key into the ciphertext encrypted under the delegatee’s public key. In addition, only the delegatee’s email gateway with a trapdoor can test whether or not a given cipheretext containing some keyword, but can learn nothing else about the sensitive data of email. We proposed an identity-based proxy re-encryption with keyword search scheme, where the delegator and the delegatee extract keys from a trusted party called the key generator center (KGC), who generates public-private key pair for delegator and delegatee based on their identities. Meanwhile, the identity-based proxy re-encryption with keyword search scheme satisfies the properties of PRE including unidirectionality, multi-use and transparency. Additionally, the proposed scheme is efficient in terms of both computation and communication, and can realize security privacy preserving in cloud computing environments.
Federated deep learning for detecting COVID-19 lung abnormalities in CT: a privacy-preserving multinational validation study
