An Efficient MobileHealthcare Emergency Framework Mobile technologies are capable of offering individual level health care services to users. Mobile Healthcare (mHealthcare) frameworks, which feature smartphone (SP) utilizations of ubiquitous computing made possible by applying wireless Body Sensor Networks (BSNs), have been introduced recently to provide SP clients with health condition monitoring and access to medical attention when necessary. However, in a vulnerable mHealthcare framework, clientsxe2x80x99 personal info and sensitive data can easily be poached by intruders or any malicious party, causing serious security problems and confidentiality issues. In 2013, Lu et al. proposed a mobileHealthcare emergency framework based on privacypreserving opportunistic computing (SPOC), claiming that their splendid SPOC construction can opportunistically gather SP resources such as computing power and energy to handle computingintensive Personal Health Information (PHI) with minimal privacy disclosure during an emergency. To balance between the risk of personal health information exposure and the essential PHI processing and transmission, Lu et al. presented a patientcentric privacy ingress control framework based on an attributebased ingress control mechanism and a PrivacyPreserving Scalar Product Computation (PPSPC) technique. In spite of the ingenious design, however, Lu et al.xe2x80x99s framework still has some security flaws in such aspects as client anonymity and mutual authentication. In this article, we shall offer an improved version of Lu et al.xe2x80x99s framework with the security weaknesses mended and the computation efficiency further boosted. In addition, we shall also present an enhanced mobileHealthcare emergency framework using Partial Discrete Logarithm (PDL) which does not only achieve flawless mutual authentication as well as client anonymity but also reduce the computation cost.

A New Secret Handshake Scheme with MultiSymptom Intersection for Mobile Healthcare Social Networks Abstract   With the aggravating trend of aging population in modern societies, Mobile Healthcare Social Network (MHSN) is an attracting platform for improving the life quality of elderly patients and offering mutual supports. In a sustainable MHSN system, one essential issue is to protect sensitive healthcare information while providing informationsharing for patients with multiple symptoms. To achieve multisymptom matching and crossdomain communications for patients in MHSNs, we propose a new Secret Handshake scheme with MultiSymptom intersection ( MSSH ), which is derived from a linearcomplexity Authorized Private Set Intersection (APSI) based on Schnorr signature. In  MSSH , two anonymous patients, who have registered with independent healthcare centers, are able to successfully execute an affiliationhiding mutual anonymous authentication only if their target authentication policies are satisfied. The authentication policy demands that the designated healthcare center should be matched and the cardinality of their symptoms intersection is not less than a threshold value. Meanwhile, the symptoms outside of the set intersection remain confidential. The formal analysis proves  MSSH  is secure under the Random Oracle Model (ROM). The experimental results demonstrate that  MSSH  is efficient and feasible in MHSNs.