PARFAIT: Privacy-preserving, secure, and low-delay service access in fog-enabled IoT ecosystems

Traditional fog-enabled IoT ecosystems always assume fully-trusted and secure fog nodes, offering computational capabilities and storage space closer to constrained IoT devices. However, such security-related assumptions can easily fall when considering the exposure of fog nodes’ location, the heterogeneity of device providers, and the ease of misuse and misconfigurations by end-users, to name a few. As a result, compromised fog nodes can stealthily steal sensitive information, such as the devices’ location, path, and private personal attributes. This paper presents PARFAIT, a privacy-preserving, secure, and low-delay framework for securely accessing services in fog-enabled IoT ecosystems. PARFAITguarantees low-delay authentication and authorization to local fog nodes, protecting the identity and the attributes possessed by the IoT devices. Moreover, PARFAITuses rolling ephemeral identities, providing unlinkability among access requests, thus preventing the tracking of mobile IoT devices by multiple compromised fog nodes. We performed several experimental tests on a reference proof-of-concept to show the viability of PARFAIT. Specifically, adopting an elliptic curve with a group size of 512 bits, PARFAITallows the access to a single protected resource in only 0.274 s, and such a delay rises to only 0.359 s with 10 consecutive requests (66.8% less than the quickest competing approach).