###### Abstract  
With the advent of modern technologies, including the IoT and blockchain, smart-parking (SP) systems are becoming smarter and smarter. Similar to other automated systems, and particularly those that require automation or minimal interaction with humans, the SP system is heuristic in delivering performances, such as throughput in terms of latency, efficiency, privacy, and security, and it is considered a long-term cost-effective solution. This study looks ahead to future trends and developments in SP systems and presents an inclusive, long-term, effective, and well-performing smart autonomous vehicle parking (SAVP) system that explores and employs the emerging fog-computing and blockchain technologies as robust solutions to strengthen the existing collaborative IoT-cloud platform to build and manage SP systems for autonomous vehicles (AVs). In other words, the proposed SAVP system offers a smart-parking solution, both indoors and outdoors, and mainly for AVs looking for vacant parking, wherein the fog nodes act as a middleware layer that provides various parking operations closer to IoT-enabled edge devices. To address the challenges of privacy and security, a lightweight integrated blockchain and cryptography (LIBC) module is deployed, which is functional at each fog node, to authorize and grant access to the AVs in every phase of parking (e.g., from the parking entrance to the parking slot to the parking exit). A proof-of-concept implementation was conducted, wherein the overall computed results, such as the average response time, efficiency, privacy, and security, were examined as highly efficient to enable a proven SAVP system. This study also examined an innovative pace, with careful considerations to combatting the existing SP-system challenges and, therefore, to building and managing future scalable SP systems. Internet of Things; cloud computing; fog/edge computing; smart autonomous parking system; radio-frequency identification; blockchain; cryptography +
Footnote †: journal: _Sensors_  
The technological evolution of WSNs makes it viable to use various types of sensors, such as ultrasonic, magnetic, radio-frequency identification (RFID), optical, infrared (IR), Honeywell, etc., as well as communication protocols such as Bluetooth, Wi-Fi, ZigBee, 6 LoWPAN, etc., to acquire the vacant parking information for the end user that is mainly connected through cellular applications and functions via backend servers (e.g., cloud servers) [5; 6]. Thus, the usage of various sensors, embedded technologies, and their deployments in WSNs play vital roles in fulfilling the technological demands of modern SP systems [2; 7]. However, such sensors and wireless communication standards come with several limitations to their designs, operational incompatibilities, protocol interoperability, data exchanging, environmental obstacles, etc., that disable the quality of service (QoS) (for example, in the case of managing and controlling a large SP system that offers a high probability of routing the overall parking information to its end user on demand in real time) [8; 9]. In practice, the SP system is operational in WSNs, wherein field sensors and devices are networked to exchange information with a central controller over the Internet. The gateways are used to collect information from the field sensors or devices to transmit the carried information back to the central controller, or cloud server. The cloud server is designed to collect, store, and analyze large amounts of data from several distributive parking stations, and therefore manages the enormous end-user requests for parking. However, the cloud-centric platform has limitations in fulfilling the vast growing demands of modern SP systems (for example, an SP system that has connectivity with several parking stations, and each station is composed of several thousand parking slots) [1; 10; 11].