Secure Multi-Receiver Communication and SM2 Based Encryption Scheme

Cloud users can confirm the data integrity without obtaining the complete file thanks to Provable Data Possession (PDP). The Public Key Infrastructure (PKI) is the foundation of all current PDP solutions. The plan is effective, adaptable, and allows for public, delegated, and private verification. 2 The failure to attain soundness makes Ack-Ib-Dpdp defective. Present a generic construction to address the issue. An extension of the fundamental 2 Ack-Ib-Dpdp protocol to a multi-cloud environment yields a new 2 Ack-Ib-Dpdp protocol. Cloud-based data storage and sharing systems facilitate group data modification and sharing. Users in the group must compute signatures on each block in the shared data to guarantee that its integrity can be publicly verify. Because various users conduct distinct data modifications, different users typically sign separate blocks in shared data. Since each block needs to be signed, then upon the revocation of a user from any group, all blocks previously signed by this user should be signed by an active user for security purposes. Due to a huge amount of shared data at the cloud, it is not so trivial to download the relevant data segments by an existing user and then re-sign upon revocation.