A new ciphertext based OT protocol in cloud computing

Cloud computing is the on-demand availability of computer system resources, especially computing power. Cloud computing relies on sharing resources to achieve coherence, and it needs to communicate frequently with the user. In addition, the user's information must be kept secret from the cloud, and additional computing information in the cloud should also be kept private from the user. The problem can be solved with oblivious transfer. Oblivious transfer (OT) protocols are an essential part of secure multi-party computation in cryptography. However, the previous scheme of OT is inefficient. When messages need to be transmitted multiple times, it becomes challenging to use in protecting privacy data transfer for cloud computing. In this paper, we analyze the features of cloud computing and the former OT protocols based on public key encryption (PKE) and Diffie-Hellman (DH). We propose a new OT protocol strategy, which uses a function in the ciphertext. We map the obtained symmetric public key and reduce computation for the protocol based on DH. We provide an implementation on cloud computing and compare our protocols with well-known OTs. In cloud computing, it shows that the time for each OT is almost negligible. In addition, the experimental results show that our protocol is at least 24% to 40% more efficient than other protocols. On the premise of ensuring user privacy, our strategy can make cloud data transmission more efficient.