New Certificateless Aggregate Signature Scheme for Healthcare Multimedia Social Network on Cloud Environment

With the application of sensor technology in the field of healthcare, online data sharing in healthcare industry attracts more and more attention since it has many advantages, such as high efficiency, low latency, breaking the geographical location, and time constraints. However, due to the direct involvement of patient health information, the privacy and integrity of medical data have become a matter of much concern to the healthcare industry. To retain data privacy and integrity, a number of digital signature schemes have been introduced in recent years. Unfortunately, most of them suffer serious security attacks and do not perform well in terms of computation overhead and communication overhead. Very recently, Pankaj Kumar et al. proposed a certificateless aggregate signature scheme for healthcare wireless sensor network. They claimed that their signature scheme was able to withstand a variety of attacks. However, in this paper, we find that their scheme fails to achieve its purpose since it is vulnerable to signature forgery attack and give the detailed attack process. Then, we propose a new certificateless aggregate signature scheme to fix the security flaws and formally prove that our proposed scheme is secure under the computationally hard Diffie-Hellman assumption. Security analysis and performance evaluation demonstrate that the security of our proposal is improvedwhile reducing the computation cost. Compared with Pankaj Kumar et al.' s scheme, our proposed scheme is more efficient and suitable for the healthcare wireless sensor networks (HWSNs) to maintain security at various levels.