CTET+: A Beyond-Birthday-Bound Secure Tweakable Enciphering Scheme Using a Single Pseudorandom Permutation

International audienceIn this work, we propose a construction of 2-round tweakable substitution permutation networks using a single secret S-box. This construction is based on non-linear permutation layers using independent round keys, and achieves security beyond the birthday bound in the random permutation model. When instantiated with an n-bit block cipher with ωn-bit keys, the resulting tweakable block cipher, dubbed CTET+, can be viewed as a tweakable enciphering scheme that encrypts ωκ-bit messages for any integer ω ≥ 2 using 5n + κ-bit keys and n-bit tweaks, providing 2n/3-bit security. Compared to the 2-round non-linear SPN analyzed in [CDK+18], we both minimize it by requiring a single permutation, and weaken the requirements on the middle linear layer, allowing better performance. As a result, CTET+ becomes the first tweakable enciphering scheme that provides beyond-birthday-bound security using a single permutation, while its efficiency is still comparable to existing schemes including AES-XTS, EME, XCB and TET. Furthermore, we propose a new tweakable enciphering scheme, dubbed AES6-CTET+, which is an actual instantiation of CTET+ using a reduced round AES block cipher as the underlying secret S-box. Extensive cryptanalysis of this algorithm allows us to claim 127 bits of security.Such tweakable enciphering schemes with huge block sizes become desirable in the context of disk encryption, since processing a whole sector as a single block significantly worsens the granularity for attackers when compared to, for example, AES-XTS, which treats every 16-byte block on the disk independently. Besides, as a huge amount of data is being stored and encrypted at rest under many different keys in clouds, beyond-birthday-bound security will most likely become necessary in the short term

Redesigning the Information Assurance Undergraduate Curriculum at Regis University

When Regis University created the eSecurity curriculum in 2003, the lessons were pertinent to the then-current threats. Although the curriculum has slightly changed since then, the courses needed a major facelift to meet the ever changing cyber threats. The question of can Information Assurance courses at Regis University be refreshed to include virtual labs so they are based on ethical standards will be answered in this paper. Utilizing the Design Science methodology and incorporating Bloom â„¢s Taxonomy and the Jesuit educational approach, curriculum was identified and developed for the classroom and online students. By working with the Regis Distance Learning department, the thesis project was submitted for publication as part of the Regis Computer Networking courses

Non-malleable codes for space-bounded tampering

Non-malleable codes—introduced by Dziembowski, Pietrzak and Wichs at ICS 2010—are key-less coding schemes in which mauling attempts to an encoding of a given message, w.r.t. some class of tampering adversaries, result in a decoded value that is either identical or unrelated to the original message. Such codes are very useful for protecting arbitrary cryptographic primitives against tampering attacks against the memory. Clearly, non-malleability is hopeless if the class of tampering adversaries includes the decoding and encoding algorithm. To circumvent this obstacle, the majority of past research focused on designing non-malleable codes for various tampering classes, albeit assuming that the adversary is unable to decode. Nonetheless, in many concrete settings, this assumption is not realistic

Information security, data breaches, and protecting cardholder information: facing up to the challenges

On September 13 and 14, 2006, the Payment Cards Center of the Federal Reserve Bank of Philadelphia and the Electronic Funds Transfer Association (EFTA) hosted a conference entitled “Information Security, Data Breaches, and Protecting Cardholder Information: Facing Up to the Challenges.” The two-day event was designed to bring together a diverse set of stakeholders from the U.S. payments industry to discuss a framework to guide industry practices and inform public policy. This paper summarizes key highlights from this event. Conference participants emphasized that the industry must address two fundamental issues: (1) increasingly dangerous threats to sensitive consumer information and (2) public perception and understanding of the risks from data breaches. These challenges are related but need different solutions. A consensus emerged that while the situation is not yet dire, it is serious, and warrants attention from all payments stakeholders.Data protection ; Payment systems ; Computer security

Telescience Testbed Pilot Program

The Telescience Testbed Pilot Program is developing initial recommendations for requirements and design approaches for the information systems of the Space Station era. During this quarter, drafting of the final reports of the various participants was initiated. Several drafts are included in this report as the University technical reports

Secure portable execution and storage environments: A capability to improve security for remote working

Remote working is a practice that provides economic benefits to both the employing organisation and the individual. However, evidence suggests that organisations implementing remote working have limited appreciation of the security risks, particularly those impacting upon the confidentiality and integrity of information and also on the integrity and availability of the remote worker’s computing environment. Other research suggests that an organisation that does appreciate these risks may veto remote working, resulting in a loss of economic benefits. With the implementation of high speed broadband, remote working is forecast to grow and therefore it is appropriate that improved approaches to managing security risks are researched. This research explores the use of secure portable execution and storage environments (secure PESEs) to improve information security for the remote work categories of telework, and mobile and deployed working. This thesis with publication makes an original contribution to improving remote work information security through the development of a body of knowledge (consisting of design models and design instantiations) and the assertion of a nascent design theory. The research was conducted using design science research (DSR), a paradigm where the research philosophies are grounded in design and construction. Following an assessment of both the remote work information security issues and threats, and preparation of a set of functional requirements, a secure PESE concept was defined. The concept is represented by a set of attributes that encompass the security properties of preserving the confidentiality, integrity and availability of the computing environment and data. A computing environment that conforms to the concept is considered to be a secure PESE, the implementation of which consists of a highly portable device utilising secure storage and an up-loadable (on to a PC) secure execution environment. The secure storage and execution environment combine to address the information security risks in the remote work location. A research gap was identified as no existing ‘secure PESE like’ device fully conformed to the concept, enabling a research problem and objectives to be defined. Novel secure storage and execution environments were developed and used to construct a secure PESE suitable for commercial remote work and a high assurance secure PESE suitable for security critical remote work. The commercial secure PESE was trialled with an existing telework team looking to improve security and the high assurance secure PESE was trialled within an organisation that had previously vetoed remote working due to the sensitivity of the data it processed. An evaluation of the research findings found that the objectives had been satisfied. Using DSR evaluation frameworks it was determined that the body of knowledge had improved an area of study with sufficient evidence generated to assert a nascent design theory for secure PESEs. The thesis highlights the limitations of the research while opportunities for future work are also identified. This thesis presents ten published papers coupled with additional doctoral research (that was not published) which postulates the research argument that ‘secure PESEs can be used to manage information security risks within the remote work environment’