Security Analysis of Randomize-Hash-then-Sign Digital Signatures

At CRYPTO 2006, Halevi and Krawczyk proposed two randomized hash function modes and analyzed the security of digital signature algorithms based on these constructions. They showed that the security of signature schemes based on the two randomized hash function modes relies on properties similar to the second preimage resistance rather than on the collision resistance property of the hash functions. One of the randomized hash function modes was named the RMX hash function mode and was recommended for practical purposes. The National Institute of Standards and Technology (NIST), USA standardized a variant of the RMX hash function mode and published this standard in the Special Publication (SP) 800-106. In this article, we first discuss a generic online birthday existential forgery attack of Dang and Perlner on the RMX-hash-then-sign schemes. We show that a variant of this attack can be applied to forge the other randomize-hash-then-sign schemes. We point out practical limitations of the generic forgery attack on the RMX-hash-then-sign schemes. We then show that these limitations can be overcome for the RMX-hash-then-sign schemes if it is easy to find fixed points for the underlying compression functions, such as for the Davies-Meyer construction used in the popular hash functions such as MD5 designed by Rivest and the SHA family of hash functions designed by the National Security Agency (NSA), USA and published by NIST in the Federal Information Processing Standards (FIPS). We show an online birthday forgery attack on this class of signatures by using a variant of Dean’s method of finding fixed point expandable messages for hash functions based on the Davies-Meyer construction. This forgery attack is also applicable to signature schemes based on the variant of RMX standardized by NIST in SP 800-106. We discuss some important applications of our attacks and discuss their applicability on signature schemes based on hash functions with ‘built-in’ randomization. Finally, we compare our attacks on randomize-hash-then-sign schemes with the generic forgery attacks on the standard hash-based message authentication code (HMAC).

On Randomizing Hash Functions to Strengthen the Security of Digital Signatures

Halevi and Krawczyk proposed a message randomization algorithm called RMX as a front-end tool to the hash-then-sign digital signature schemes such as DSS and RSA in order to free their reliance on the collision resistance property of the hash functions. They have shown that to forge a RMX-hash-then-sign signature scheme, one has to solve a cryptanalytical task which is related to finding second preimages for the hash function. In this article, we will show how to use Dean’s method of finding expandable messages for finding a second preimage in the Merkle-Damgård hash function to existentially forge a signature scheme based on a t-bit RMX-hash function which uses the Davies-Meyer compression functions (e.g., MD4, MD5, SHA family) in 2 t/2 chosen messages plus 2 t/2 + 1 off-line operations of the compression function and similar amount of memory. This forgery attack also works on the signature schemes that use Davies-Meyer schemes and a variant of RMX published by NIST in its Draft Special Publication (SP) 800-106. We discuss some important applications of our attack.

Literacy and Digital Culture in the Early Years

In this chapter we present data drawn from observations of kindergarten children using iPads and talk with the children, their parents/guardians and teachers. We identify a continuum of practices that extends from ‘educational apps’ teaching handwriting, sight words and so forth to uses of the iPad as a device for multimodal literacy development and substantive conversation around children’s creative work. At the current time high stakes testing and the implementation of the Australian Curriculum are prompting new public and professional conversations about literacy and digital technology. The iPad is construed as both cause of and solution to problems of traditional literacy education. In this context we describe the literacies enabled by educational software available on iPads. We higlight the time constraints which bore on teachers' capacity to enact their visions of literacy education through the iPad platform and suggest ways of reflecting on responses to this constraint.

Designing a digital experience for young children with developmental disabilities

This paper reports on the development of a playful digital experience, Anim-action, designed for young children with developmental disabilities. This experience was built using the Stomp platform, a technology designed specifically to meet the needs of people with intellectual disability through facilitating whole body interaction. We provide detail on how knowledge gained from key stakeholders informed the design of the application and describe the design guidelines used in the development process. A study involving 13 young children with developmental disabilities was conducted to evaluate the extent to which Anim-action facilitates cognitive, social and physical activity. Results demonstrated that Anim-action effectively supports cognitive and physical activity. In particular, it promoted autonomy and encouraged problem solving and motor planning. Conversely, there were limitations in the system’s ability to support social interaction, in particular, cooperation. Results have been analyzed to determine how design guidelines might be refined to address these limitations.

Global journalism in the digital age

Mass media have transitioned in the past five years from being one-way communication mediums, from journalists to audiences, into an era of networked digital media in which individuals can easily publish text, photos and video to a world-wide audience.The power of the press is severely threatened and its business model is broken...

Global journalism investigations in the digital age: Connections and collaborations

Investigative journalists who join what theorist Manuel Castells describes as the ‘network society’ can locate potential news sources using various social media platforms and interview them using Web-based communication technologies. The potential for journalistic investigations involving multi-directional conversations with news sources across the globe is beginning to be explored. Potential news sources who are part of the network society have unprecedented access to specialist investigative reporters irrespective of their location and can speak to them more cost effectively than in the past. This paper explores how new journalism technologies are allowing journalists to call powerful individuals and institutions to account, irrespective of national borders; and how previously silenced individuals are being given a voice. To read an example of international investigative journalism facilitated by a combination of social media, Web-based communications, reporter collaboration and news outlet collaborations see http://www.theaustralian.com.au/news/features/churchs-wall-of-silence-on-sexual-abuse/story-e6frg6z6-1226639077238.

Evidence-based business process management: Using digital opportunities to drive organizational innovation

Process improvement and innovation are risky endeavors, like swimming in unknown waters. In this chapter, I will discuss how process innovation through BPM can benefit from Research-as-a-Service, that is, from the application of research concepts in the processes of BPM projects. A further subject will be how innovations can be converted from confidence-based to evidence-based models due to affordances of digital infrastructures such as large-scale enterprise soft-ware or social media. I will introduce the relevant concepts, provide illustrations for digital capabilities that allow for innovation, and share a number of key takeaway lessons for how organizations can innovate on the basis of digital opportunities and principles of evidence-based BPM: the foundation of all process decisions in facts rather than fiction.

Theorizing why in digital learning: Opening frontiers for inquiry and innovation with technology

Asking why is an important foundation of inquiry and fundamental to the development of reasoning skills and learning. Despite this, and despite the relentless and often disruptive nature of innovations in information and communications technology (ICT), sophisticated tools that directly support this basic act of learning appear to be undeveloped, not yet recognized, or in the very early stages of development. Why is this so? To this question, there is no single factual answer. In response, however, plausible explanations and further questions arise, and such responses are shown to be typical consequences of why-questioning. A range of contemporary scenarios are presented to highlight the problem. Consideration of the various inputs into the evolution of digital learning is introduced to provide historical context and this serves to situate further discussion regarding innovation that supports inquiry-based learning. This theme is further contextualized by narratives on openness in education, in which openness is also shown to be an evolving construct. Explanatory and descriptive contents are differentiated in order to scope out the kinds of digital tools that might support inquiry instigated by why-questioning and which move beyond the search paradigm. Probing why from a linguistic perspective reveals versatile and ambiguous semantics. The why dimension—asking, learning, knowing, understanding, and explaining why—is introduced as a construct that highlights challenges and opportunities for ICT innovation. By linking reflective practice and dialogue with cognitive engagement, this chapter points to specific frontiers for the design and development of digital learning tools, frontiers in which inquiry may find new openings for support.

Decolonizing digital heritage practices for Indigenous literacy: A multimodal analysis of iPad Tellagami videos

Purpose Drawing on multimodal texts produced by an Indigenous school community in Australia, we apply critical race theory and multimodal analysis to decolonize digital heritage practices for Indigenous students. This study focuses on the particular ways in which students’ counter-­‐narratives about race were embedded in multimodal and digital design in the development of a digital cultural heritage (Giaccardi, 2012). Pedagogies that explore counter-­‐narratives of cultural heritage in the official curriculum can encourage students to reframe their own racial identity, while challenging dominant white, historical narratives of colonial conquest, race, and power (Gutierrez, 2008). The children’s digital “Gami” videos, created with the iPad application, Tellagami, enabled the students to imagine hybrid, digital social identities and perspectives of Australian history that were tied to their Indigenous cultural heritage (Kamberelis, 2001).

New paradigm, new educational requirements? Australian viewpoints on education for digital libraries

The rise in popularity of the digital library has lead to studies addressing digital library education and curricula development to emanate from the United States and Europe. However, to date very little research has been conducted with an Australian focus. Additionally, very few studies worldwide have sought the opinions of practitioners and the influence that these opinions may have on developing appropriate digital library curricula. The current paper is drawn from a larger study which sought to determine the skills and knowledge required of library and information professionals to work in a digital library environment. Data were collected via an online questionnaire from two target groups: practitioners working in academic libraries and Library and Information Science (LIS) educators across Australia. This paper examines in depth the findings from the survey specifically relating to the following topics. Firstly, whether or not there is a need for an educational programme to be targeted solely at the digital library environment. Secondly, the preferred delivery options for such a programme, and preferred models of digital library education. In addition, a determination on the elements which should be included in the curricula of a digital library education programme are discussed. Findings are compared and discussed with reference to the literature which informed the study. Finally, implications for the sustainability of library education programmes in Australia are identified and directions for further research highlighted.

(Digital library) education or (digital) library education? An Australian perspective

Education for Library and Information professionals in the digital environment has been an important discussion point the world over. However, before designing and implementing a programme for digital library education, it is prudent that the skills and knowledge required to work in this environment are identified to enable informed decisions to be made. Hitherto, there has been very little research which has sought the opinion of both educators and practitioners on this topic, and none with a wide geographical coverage of Australia. This paper presents the key findings of research undertaken at Tallinn University in the first half of 2009.

Using a free online questionnaire to determine the skills, competencies and knowledge required to work in a digital library environment in Australia

This paper discusses the data collection technique used to determine the skills and knowledge required of academic librarians working in a digital library environment in Australia. The research was undertaken as part of the researcher’s master’s thesis conducted at Tallinn University. The data collection instrument used was a freely available online survey tool, and its advantages and disadvantages are discussed in terms of the desired outcomes and circumstances surrounding the thesis project. Decisions regarding the design of the questionnaire are also discussed.

Applying digital product memories in industrial production

Industrial production and supply chains face increased demands for mass customization and tightening regulations on the traceability of goods, leading to higher requirements concerning flexibility, adaptability, and transparency of processes. Technologies for the ’Internet of Things' such as smart products and semantic representations pave the way for future factories and supply chains to fulfill these challenging market demands. In this chapter a backend-independent approach for information exchange in open-loop production processes based on Digital Product Memories DPMs is presented. By storing order-related data directly on the item, relevant lifecycle information is attached to the product itself. In this way, information handover between several stages of the value chain with focus on the manufacturing phase of a product has been realized. In order to report best practices regarding the application of DPM in the domain of industrial production, system prototype implementations focusing on the use case of producing and handling a smart drug case are illustrated.