Nowadays, the rapid growth of Internet applications open the doors for people to communicate and do business around the world and thus saving time, efforts and money. However, the success of these applications is based on protecting the data from hackers. It is well known that preventing sensitive data from hackers while they are sent through the global network is a big challenge. There are many techniques used for securing data. Some of these techniques are based on encrypting a readable text into an unreadable text using mathematical operations, while other techniques are based on encrypting a readable text into an image (e.g., the Text-to-Image Encryption algorithm – TTIE) or into musical notes using an encryption key. The encryption key must be secure and should not be sent through the Internet. This paper proposes adding a new security level to the TTIE algorithm, and demonstrates how the encryption key produced by the TTIE algorithm is exchanged with the other party using the Diffie Hellman technique. Thus, this paper proposes a modified TTIE algorithm called the Diffie Hellman Text-to-Image Encryption algorithm (DHTTIE), and tests and analyses the proposed algorithm.

Internet of Things (IoT) is a contemporary concept for connecting the existing things in our environment with the Internet for a sake of making the objects information are accessible from anywhere and anytime to support a modern life style based on the Internet. With the rapid development of the IoT technologies and widely spreading in most of the fields such as buildings, health, education, transportation and agriculture. Thus, the IoT applications require increasing data collection from the IoT devices to send these data to the applications or servers which collect or analyze the data, so it is a very important to secure the data and ensure that do not reach a malicious adversary. This paper reviews some attacks in the IoT applications and the security weaknesses in the IoT environment. In addition, this study presents the challenges of IoT in terms of hardware, network and software. Moreover, this paper summarizes and points to some attacks on the smart car, smart home, smart campus, smart farm and healthcare.

nowadays, the success of many online applications relays on keeping the data sent through the global network secure and far away from hackers. To carry out this task, the two communicating parties must exchange keys during their session. Some of the key exchange protocols are called key agreement protocols. The Elliptic Curve-Diffie Hellman (ECDH) is one of the most efficient algorithms for securing data. The ECDH is more efficient than other traditional techniques such as Rivest-Shamir-Adleman (RSA) in terms of key size, computation and network bandwidth. The Authenticated Key Agreement (AKA) protocol is used for establishing a common session key between the two communicating parties. The common session key is used for subsequent cryptography goals. Most of the key agreement protocols (e.g. Menezes-Qu-Vanstone(MQV) family) generate one key per session therefore increasing the opportunities for guessing the session key. In this paper, we focus on developing an enhanced multiple sessions key which is based on ECDH. We propose an efficient and secure AKA protocol which is based on the ideas of the hashed MQV (HMQV), the YAK protocol as a robust key agreement based on public key authentication and multiple session keys. The proposed protocol generates multiple common keys per a session, where the generated common key depends on the static and ephemeral keys. Furthermore, the proposed protocol overcomes the attacks on the HMQV and YAK protocols and provides desirable security properties as compared with the related works in this paper.

Internet of Things (IoT) is defined as an inanimate object which is designed with built-in wireless connectivity, and monitored, controlled and linked over the internet. As any new technology, IoT is confusing for the normal consumer especially as debates swirl around standardization, security and privacy. This paper presents the IoT applications such as home automation, healthcare, smart grid, smart city and smart car and focuses on how to secure the generated data by IoT devices from an unauthorized access. The IoT consists of devices which are constrained in their computational capability, network bandwidth, packet size and memory such as sensor nodes. This paper demonstrates that a lightweight and mutual authentication protocols are a fundamental building block for providing the mutual authentication between user and devices in the IoT applications. Furthermore, this paper surveys some of authenticated key agreement protocols for securing IoT and presents a comparison between them in terms of security and performance.