IoT promises a new era of connectivity that goes beyond laptops and smart connected devices to connected vehicles, smart homes, smart cities and connected healthcare. The huge volume of data that is collected from millions of IoT devices raises information security and privacy concerns for users. This paper presents a new scalable encryption technique, called Flexible encryption Technique (FlexenTech), to protect IoT data during storage and in transit. FlexenTech is suitable for resource constrained devices and networks. It offers a low encryption time, defends against common attacks such as replay attacks and defines a configurable mode, where any number of rounds or key sizes may be used. Experimental analysis of FlexenTech shows its robustness in terms of its multiple configurable confidentiality levels by allowing various configurations.This configurability provides several advantages for resource constrained devices, including reducing the encryption computation time by up to 9.7% when compared to its best rivals in the literature.

This paper presents a technical method to monitor the water distribution pipelines against leakage and to control the pump when the water level decreases in the tank. Water leakage is the most popular cause of water wasted in the domestic water distribution systems. Nowadays most people have their smartphone nearby them; therefore, adding an interface on the smartphone to control an automated system is a big plus. Energy saving is a benefit of the Optimization Water Leakage Detection (OWLD) system. It enables us to save energy, time and cost by having smart leakage detection in pipelines, measuring the water level in the tank and controlling the pump when the water level is low. This paper focuses mainly on two parts: The first part is an alarm based on Global System for Mobile technology (GSM) to send a Short Message Service (SMS) to the owner. This is made up of the following components: sensors, GSM Module, Arduino and relays to control the device. The second is the controlling part; it uses android application mobile to control the pump. The proposed system can effectively improve the efficiency of operation, reduce delay time and cost of maintenance pipelines after leakage detection.

Comments are used to explain the meaning of code and ease communications between programmers themselves, quality assurance auditors, and code reviewers. A tool has been developed to help programmers write readable comments and measure their readability level. It is used to enhance software readability by providing alternatives to both keywords and comment statements from a local database and an online dictionary. It is also a word-finding query engine for developers. Readability level is measured using three different formulas: the fog index, the Flesch reading ease score, and Flesch–Kincaid grade levels. A questionnaire has been distributed to 42 programmers and 35 students to compare the readability aspect between both new comments written by the tool and the original comments written by previous programmers and developers. Programmers stated that the comments from the proposed tool had fewer complex words and took less time to read and understand. Nevertheless, this did not significantly affect the understandability of the text, as programmers normally have quite a high level of English. However, the results from students show that the tool affects the understandability of text and the time taken to read it, while text complexity results show that the tool makes new comment text that is more readable by changing the three studied variables.

This paper proposes a quality matchmaker which introduces four algorithms or filters: interface matching, quality criteria matchmaking, quality value constraints matching, and mathematical matchmaking. These four algorithms use the quality matchmaker subcomponents to implement their roles. The quality matchmaker has three sub-components which are: interface matchmaking, quality criteria matchmaking and mathematical matchmaking.A quality matchmaking process (QMP) is introduced to demonstrate the above four algorithms and to select the best Web service. The mathematical matchmaking algorithm is the most important step that uses a mathematical model in order to select the best candidates Web service based on requester's quality requirements and preferences. Two techniques are used in a mathematical model: Analytical Hierarchy Process (AHP) and Euclidean distance.Index Terms-Web services, quality matchmaker, quality matchmaking process, mathematical model

Nowadays, cloud computing offers a digital infrastructure for smart city development. Cognitive cities are steadily automating daily urban processes. The ever expanding objective-driven communities gather and share sensitive data that must be stored securely. Cloud computing offers a suitable platform that allows cognitive smart cities to access and re-access data to learn from their past to adapt its current behaviour. However, the cloud is an untrusted entity that may expose data when decrypted for processing by systems. In this paper, we treat the issue of encrypted data processing. Often, the data is encrypted prior to transferring it to the cloud, where the cloud must have the data in clear to be able to make calculations which raises security and privacy threats if the cloud is considered untrusted. The scenario of asking users to make the calculations after decrypting the received cloud data and encrypting the obtained results before sending them back to the cloud is not a practical solution in distributed multi-tenant architectures. Homomorphic encryption allows offers a solution for processing encrypted data. Many existing homomorphic encryption schemes suffer from limitations that hinder their usability. This paper presents an efficient fully homomorphic encryption scheme using twin key encryption and magic number fragmentation. The details of the scheme are presented along with cryptanalytic attacks to assess its effectiveness. The proposed scheme exhibits strong resilience against brute-force attacks compared to its rivals from the literature.Finally, we illustrate the applicability of the proposed scheme using a cognitive smart city application.