Secure Fog-assisted Sharing for Multimedia Health Records in the Cloud

In recent years, multimedia has been widely used in the medical and health fields and plays a pivotal role in personal health records (PHR). In the PHR system, people can easily access to their PHR data, which is mainly composed of X-ray, ECG and other multimedia data, by mobile devices. Owing to the need for efficiently accessing to the PHR data, the hybrid cloud-fog system is very suitable for the storage of PHR data because the computing capacity in this system is extended to the edge of the network to achieve low delay. PHR data generally contains a lot of sensitive information that may be directly used for medical diagnosis, so it demands more security capacity to ensure the fine-grained access control, confidentiality and validity of data, while protecting the privacy of data owners. Moreover, PHR systems should allow data owners to share their PHR data with specific institutions or individuals. For resolving the above problems, we propose a secure fog-assisted sharing scheme for multimedia PHR in the cloud based on multi-authority attributebased signcryption, called SFSP. In the scheme, outsourcing computing is involved to transfer some computation to fog nodes to reduce the computation overhead on the user side in the signcryption and decryption stages because of the limited computing power of normal users' mobile devices. Performance analysis shows that SFSP is more suitable for the sharing of PHR in the cloud due to its higher efficiency than the existing schemes.This work is supported by the Key Industry Innovation Chain Project of Shaanxi (No. 2019ZDLGY13-05, No. 2019ZDLGY12-01), and Collaborative Innovation Center of Information Sensing and Understanding at Xidian University