A Privacy-Preserving Data Transmission Scheme Based on Oblivious Transfer and Blockchain Technology in the Smart Healthcare

With the development of the Internet of Things and the demand for telemedicine, the smart healthcare system has attracted much attention in recent years. As a platform for medical data interaction, the smart healthcare system is demanded to ensure the privacy of both the receiver and the sender, as well as the security of data transmission. In this paper, we propose a privacy-preserving data transmission scheme where both secure ciphertext conversion and malicious users identification are supported. In particular, the <a:math xmlns:a="http://www.w3.org/1998/Math/MathML" id="M1"> <a:msubsup> <a:mrow> <a:mfenced open="(" close=")" separators="|"> <a:mrow> <a:mtext>OT</a:mtext> </a:mrow> </a:mfenced> </a:mrow> <a:mi>m</a:mi> <a:mi>n</a:mi> </a:msubsup> </a:math> protocol is introduced to guarantee the two-way privacy of communication parties. Meanwhile, we adopt proxy reencryption algorithm to support secure ciphertext conversion so as to ensure the confidentiality of data in many-to-many communication pattern. In addition, by taking advantage of the concept of blockchain technology, a novel <f:math xmlns:f="http://www.w3.org/1998/Math/MathML" id="M2"> <f:msubsup> <f:mrow> <f:mfenced open="(" close=")" separators="|"> <f:mrow> <f:mtext>OT</f:mtext> </f:mrow> </f:mfenced> </f:mrow> <f:mi>m</f:mi> <f:mi>n</f:mi> </f:msubsup> </f:math> protocol is proposed to prevent data from being tampered with and effectively identify malicious users. Theoretical and experimental analyses indicate that the proposed scheme is practical for smart healthcare with high security and efficiency.