Technology has become intertwined into society daily life which is not only limited to personal life but also extending into the business world. Availability, integrity and confidentiality are critical information security factors to consider when interacting with technology. Conversely many unsuspecting users have fallen prey to cyber criminals. The majority of threats encountered could have been prevented by the victims if they had sufficient knowledge to first identify and then mitigate the threat. The use of information security awareness programs provides a platform whereby users are informed about such threats. The success of these programs is significantly reduced if the content is not transferred in the most effective method to improve understanding and result in a change of behaviour. This dissertation addresses the effectiveness of using a gaming platform within an information security awareness program. The use of games allows for the users to apply knowledge within a potential scenario as seen with pilots using flight simulators. End users who have no information security background should have a safe platform where threats can be identified and methods taught to mitigate the threats. A wide selection of security awareness frameworks exist, the most appropriate framework should be considered first. The different phases of the framework would be applied within the dissertation with the main objective to ultimately determine the effectiveness of games within security awareness programs. Data was collected during the implemented information security awareness program using quantitative instruments. These included questionnaires and a developed online game designed from the literature reviewed during the study. The analysed data highlighted the effects of extrinsic motivation on knowledge transfer and validated the positive impact of game play. / Computing / M. Tech. (Information Technology)

Notre approche dans cette thèse était d'identifier où le chiffrement complètement homomorphe (FHE) pouvait être utilisé pour le domaine des sciences informatiques et de construire une plate-forme expérimentale qui nous permette de tester des algorithmes de traitement de l'information manipulant des données chiffrées. La première partie de cette thèse est consacrée à l'état de l'art. Nous présentons d'abord les systèmes de chiffrement homomorphes conçus avant 2008, puis nous présentons ceux adressant la problématique du chiffrement complètement homomorphe. Nous décrivons plusieurs méthodes de chiffrement d'intérêt pour cette thèse et discutons de leurs implémentations FHE. Enfin, nous présentons des circuits de Yao car ils peuvent résoudre des problèmes similaires que le FHE et nous parlons brièvement du chiffrement fonctionnel (FE). La deuxième partie de cette thèse présente nos contributions. Nous commençons par expliquer comment le FHE peut être utile dans divers scénarios et décrivons plusieurs cas d'utilisation pratique identifiés au cours de la thèse. Ensuite, nous décrivons notre approche pour effectuer des calculs sur des données chiffrées à l'aide du FHE et expliquons comment nous avons pu développer une plate-forme pour l'exécution dans le domaine chiffré d'une large gamme d'algorithmes en s'appuyant seulement sur l'addition et la multiplication homomorphes. Nous détaillons ensuite notre solution pour effectuer des requêtes privées sur une base de données chiffrées en utilisant le chiffrement homomorphe. Dans un dernier chapitre, nous présentons nos résultats expérimentaux. / Our approach in this thesis was to identify where FHE could be used in computer science and to build an experimental platform that allow us to test real-life algorithm running on homomorphically-encrypted data. The first part of this thesis is dedicated to the state of the art. We first present homomorphic encryption schemes designed before 2008 and then move to the Fully Homomorphic Encryption period. We describe several schemes of interest for this thesis and discuss FHE implementations. Finally, we present Yao’s garbled circuits as they can solve similar problems as FHE and briefly talk about Functional Encryption (FE). The second part of this thesis is for our contributions to the subject. We begin by explaining how FHE can be useful in various scenarios and try to provide practical use cases that we identified during the thesis. Then, we describe our approach to perform computations on encrypted data using FHE and explain how we were able to build on just the homomorphic addition and multiplication a platform for the execution in the encrypted domain of a wide range of algorithms. We then detail our solution for performing private queries on an encrypted database using homomorphic encryption. In a final chapter, we present our experimental results.

Thesis (MTech (Information Technology))--Peninsula Technikon, 2004 / Encryption was used whenever someone wanted to send a secret message to someone. The quality of the algorithm and key combination were the factors that ensured the strength of the system. However, until there were some automation one could not use complex methods for encryption because it simply took too long to encrypt and decrypt messages (even worse for images), manually. Optical technologies have recently been employed in encryption. Compared with traditional computer and electrical systems, optical technologies offer primarily two types of benefits, namely optical systems have an inherent capability for parallel processing, that is, rapid transmission of information, and information can be hidden in any of several dimensions, such as phase or spatial frequency. Optical systems therefore have an excellent capability for encoding information. In this project an image encryption technique was developed using exclusive-OR (XOR) operations in the optical domain before the captured image entered a digital computer network for further processing. A gray-level image of the object to be encrypted was converted a binary format and a pixel by pixel exclusive OR operation was performed on it with a random key-bit by making use of polarization encoding in LCD technology, before the encrypted binary image was detected by a CCD. The image may also be used as an input to a computer for comparison with a database. However, noise alters the encrypted bit and the value of the noisy encrypted bit is no longer binary. In this research the encryption techniques was evaluated and tested for applicability to encrypt and decrypt successfully. The noise performance was tested and compared. The technique was applied for image transmission over a wireless IP broadband link. Images (optical and thermal) captured from telemedicine application was transmitted and decrypted with reasonable success in this application.

M.Sc. (Information Technology) / Please refer to full text to view abstract

Electronic commerce is a large and ever growing industry. Online transactions are returning ever-growing revenues to electronic merchants. The e-commerce industry is still facing a range of problems concerning the process of completion of online transactions. Such problems are connected to consumer fears dealing with the identity of online merchants, their security pre- cautions and methods for accepting online payments. This thesis develops and presents a Mutual Authentication Model (MAM), which addresses the problem of mutual authentication between online shoppers and merchants. The model combines existing technologies in the eld of cryp- tography, as well as the use of digital signatures and certi cates. This is done in a speci c manner as for the model to achieve mutual authentication between communicating parties, in an online transactions. The Mutual Authentication Model provides a process through which an online shopper can be quickly and transparently equipped with a digital identi cation, in the form of a digital certi cate of high trust, in order for this shopper to participate in an authen- ticated transaction within the MAM. A few of the advantages of the developed model include the prospect of decreased online credit fraud, as well as an increased rate of completed online transactions. / Prof. S.H. von Solms

M.Sc. / Using the Internet for communication purposes constitutes a high risk, considering the security of such information. The protocol suite used on the Internet is the TCP/IP protocol suite, which consists of the Transmission Control Protocol (TCP) and the Internet Protocol (IP). In a bid to create a basis to support the newly conceptualised ideas, various areas of networking are briefly discussed in this dissertation. The first in this series of areas is that of the OSI layers. This model forms the basis of all networking concepts. The model describes seven layers, of which each performs a certain networking function. The TCP/IP protocol suite fits into this model. Network security and encryption methods are applied and followed to secure information on the Internet. These methods have been used over a long period of time and will also be used to support the newly conceptualised ideas. The main focus of this dissertation falls on the securing of certain parts of the information contained in the headers of both the Transmission Control Protocol (TCP) and the Internet Protocol (IP) in a bid to minimise the amount of data that may be inferred about the communicating parties from these headers. In addition, where multiple routes exist between hosts, the possibility of the deliberate distribution of a single message across these routes is examined. Such distribution will further complicate the task of a hacker attempting to gather information from TCP and IP headers. In addition, such distribution will minimise the possibility that a hacker may assemble a complete message from its constituent parts and that he/she may infer information about the message that cannot be inferred from the isolated parts. The length of a message sent between hosts is one simple example of such information.

The modern organisation relies heavily on information to function effectively. With such reliance on information, it is vital that information be protected from both internal (employees) and external threats. The protection of information or information security to a large extent depends on the behaviour of humans (employees) in the organisation. The behaviour of employees is one of the top information security issues facing organisations as the human factor is regarded as the weakest link in the security chain. To address this human factor many researchers have suggested the fostering of a culture of information security so that information security becomes second nature to employees. Information security culture as defined for this research study exists in four levels namely artefacts, espoused values, shared tacit assumptions and information security knowledge. An important step in the fostering of an information security culture is the assessment of the current state of such a culture. Gaps in current approaches for assessing information security culture were identified and this research study proposes the use of a control framework to address the identified gaps. This research study focuses on the assessment of information security culture and addresses 5 research objectives namely 1) to describe information security culture in the field of information security, 2) to determine ways to foster information security culture in an organisation, 3) to demonstrate the gap in current approaches used to assess information security culture, 4) to determine the components that could be used for the assessment of information security culture for each of the culture’s underlying levels and 5) to describe a process for the assessment of information security culture for all four levels. This research study follows a qualitative approach utilising a design science strategy and multi-method qualitative data collection techniques including literature review, qualitative content analysis, argumentation, and modelling techniques. The research methods provide a means for the interpretation of the data and the development of the proposed control framework.

Modern users carry mobile devices with them at nearly all times, and this likely has contributed to the rapid growth of private user data—such as emails, photos, and more—stored online in the cloud. Unfortunately, the security of many cloud services for user data is lacking, and the vast amount of user data stored in the cloud is an attractive target for adversaries. Even a single compromise of a user’s account yields all its data to attackers. A breach of an unencrypted email account gives the attacker full access to years, even decades, of emails. Ideally, users would encrypt their data to prevent this. However, encrypting data at rest has long been considered too difficult for users, even technical ones, mainly due to the confusing nature of managing cryptographic keys. My thesis is that strong security can be made easy to use through client-side encryption using self-generated per-device cryptographic keys, such that user data in cloud services is well protected, encryption is transparent and largely unnoticeable to users even on multiple devices, and encryption can be used with existing services without any server-side modifications. This dissertation introduces a new paradigm for usable cryptographic key management, Per-Device Keys (PDK), and explores how self-generated keys unique to every device can enable new client-side encryption schemes that are compatible with existing online services yet are transparent to users. PDK’s design based on self-generated keys allows them to stay on each device and never leave them. Management of these self-generated keys can be shown to users as a device management abstraction which looks like pairing devices with each other, and not any form of cryptographic key management. I design, implement, and evaluate three client-side encryption schemes supported by PDK, with a focus on designing around usability to bring transparent encryption to users. First, I introduce Easy Email Encryption (E3), a secure email solution that is easy to use. Usersstruggle with using end-to-end encrypted email, such as PGP and S/MIME, because it requires users to understand cryptographic key exchanges to send encrypted emails. E3 eliminates this key exchange by focusing on storing encrypting emails instead of sending them. E3 transparently encrypts emails on receipt, ensuring that all emails received before a compromise are protected from attack, and relies on widely-used TLS connections to protect in-flight emails. Emails are encrypted using self-generated keys, which are completely hidden from the user and do not need to be exchanged with other users, alleviating the burden of users having to know how to use and manage them. E3 encrypts on the client, making it easy to deploy because it requires no server or protocol changes and is compatible with any existing email service. Experimental results show that E3 is compatible with existing IMAP email services, including Gmail and Yahoo!, and has good performance for common email operations. Results of a user study show that E3 provides much stronger security guarantees than current practice yet is much easier to use than end-to-end encrypted email such as PGP. Second, I introduce Easy Secure Photos (ESP), an easy-to-use system that enables photos tobe encrypted and stored using existing cloud photo services. Users cannot store encrypted photos in services like Google Photos because these services only allow users to upload valid images such as JPEG images, but typical encryption methods do not retain image file formats for the encrypted versions and are not compatible with image processing such as image compression. ESP introduces a new image encryption technique that outputs valid encrypted JPEG files which are accepted by cloud photo services, and are robust against compression. The photos are encrypted using self-generated keys before being uploaded to cloud photo services, and are decrypted when downloaded to users’ devices. Similar to E3, ESP hides all the details of encryption/decryption and key management from the user. Since all crypto operations happen in the user’s photo app, ESP requires no changes to existing cloud photo services, making it easy to deploy. Experimental results and user studies show that ESP encryption is robust against attack techniques, exhibits acceptable performance overheads, and is simple for users to set up and use. Third, I introduce Easy Device-based Passwords (EDP), a password manager with improvedsecurity guarantees over existing ones while maintaining their familiar usage models. To encrypt and decrypt user passwords, existing password managers rely on weak, human-generated master passwords which are easy to use but easily broken. EDP introduces a new approach using self-generated keys to encrypt passwords, and an easy-to-use pairing mechanism to allow users to access passwords across multiple devices. Keys are not exposed to users and users do not need to know anything about key management. EDP is the first password manager that secures passwords even with untrusted servers, protecting against server break-ins and password database leaks. Experimental results and a user study show that EDP ensures password security with untrusted servers and infrastructure, has comparable performance to existing password managers, and is considered usable by users.

Despite the use of strong encryption schemes, one can still learn information about encrypted data using side channel attacks [2]. Watching what physical memory is being accessed can be such a side channel. One can hide this information by using oblivious simulation - hiding the true access pattern of a program. In this paper we will review the model behind oblivious simulation, attempt to formalize the problem and define a security game. We will review the major solutions pro- posed so far, the square root and hierarchical solutions, as well as propose a new variation on the square root solution. Additionally, we will show a new formalization for providing software protection by using an encryption scheme and oblivious simulation.

Tweakable ciphers are a building block used to construct a variety of cryptographic algorithms. Typically, one proves (via a reduction) that a tweakable-cipher-based algorithm is about as secure as the underlying tweakable cipher. Hence improving the security or performance of tweakable ciphers immediately provides corresponding benefits to the wide array of cryptographic algorithms that employ them. We introduce new tweakable ciphers, some of which have better security and others of which have better performance than previous designs. Moreover, we demonstrate that tweakable ciphers can be used directly (as opposed to as a building block) to provide authenticated encryption with associated data in a way that (1) is robust against common misuses and (2) can, in some cases, result in significantly shorter ciphertexts than other approaches.