arXiv subjects

Partha Das Chowdhury

Publications and source records attributed to Partha Das Chowdhury.

5 recordsLinked to original sources

arXiv2024

Assessing Effectiveness of Cyber Essentials Technical Controls

Cyber Essentials (CE) comprise a set of controls designed to protect organisations, irrespective of their size, against cyber attacks. The controls are firewalls, secure configuration, user access control, malware protection & security update management. In this work, we explore the extent to which CE remains robust against an ever-evolving threat landscape. To that end, we reconstruct 45 breaches mapped to MiTRE ATT&CK using an Incident Fault Tree ( IFT ) approach. Our method reveals the intersections where the placement of controls could have protected organisations. Then we identify appropriate Cyber Essential controls and/or Additional Controls for these vulnerable intersections. Our results show that CE controls can effectively protect against most attacks during the initial attack phase. However, they may need to be complemented with additional Controls if the attack proceeds further into organisational systems & networks. The Additional Controls (AC) we identify include back-ups, security awareness, logging and monitoring. Our analysis brings to the fore a foundational issue as to whether controls should exclude recovery and focus only on pre-emption. The latter makes the strong assumption that a prior identification of all controls in a dynamic threat landscape is indeed possible. Furthermore, any potential broadening of technical controls entails re-scoping the skills that are required for a Cyber Essentials (CE) assessor. To that end, we suggest human factors and security operations and incident management as two potential knowledge areas from Cyber Security Body of Knowledge (CyBOK) if there is any broadening of CE based on these findings.

cs.CR↗

arXiv2023

Co-creating a Transdisciplinary Map of Technology-mediated Harms, Risks and Vulnerabilities: Challenges, Ambivalences and Opportunities

The phrase "online harms" has emerged in recent years out of a growing political willingness to address the ethical and social issues associated with the use of the Internet and digital technology at large. The broad landscape that surrounds online harms gathers a multitude of disciplinary, sectoral and organizational efforts while raising myriad challenges and opportunities for the crossing entrenched boundaries. In this paper we draw lessons from a journey of co-creating a transdisciplinary knowledge infrastructure within a large research initiative animated by the online harms agenda. We begin with a reflection of the implications of mapping, taxonomizing and constructing knowledge infrastructures and a brief review of how online harm and adjacent themes have been theorized and classified in the literature to date. Grounded on our own experience of co-creating a map of online harms, we then argue that the map -- and the process of mapping -- perform three mutually constitutive functions, acting simultaneously as method, medium and provocation. We draw lessons from how an open-ended approach to mapping, despite not guaranteeing consensus, can foster productive debate and collaboration in ethically and politically fraught areas of research. We end with a call for CSCW research to surface and engage with the multiple temporalities, social lives and political sensibilities of knowledge infrastructures.

cs.HC↗

arXiv2023

Threat Models over Space and Time: A Case Study of E2EE Messaging Applications

Threat modelling is foundational to secure systems engineering and should be done in consideration of the context within which systems operate. On the other hand, the continuous evolution of both the technical sophistication of threats and the system attack surface is an inescapable reality. In this work, we explore the extent to which real-world systems engineering reflects the changing threat context. To this end we examine the desktop clients of six widely used end-to-end-encrypted mobile messaging applications to understand the extent to which they adjusted their threat model over space (when enabling clients on new platforms, such as desktop clients) and time (as new threats emerged). We experimented with short-lived adversarial access against these desktop clients and analyzed the results with respect to two popular threat elicitation frameworks, STRIDE and LINDDUN. The results demonstrate that system designers need to both recognise the threats in the evolving context within which systems operate and, more importantly, to mitigate them by rescoping trust boundaries in a manner that those within the administrative boundary cannot violate security and privacy properties. Such a nuanced understanding of trust boundary scopes and their relationship with administrative boundaries allows for better administration of shared components, including securing them with safe defaults.

cs.CR↗

arXiv2022

Better Call Saltzer \& Schroeder: A Retrospective Security Analysis of SolarWinds \& Log4j

Saltzer \& Schroeder's principles aim to bring security to the design of computer systems. We investigate SolarWinds Orion update and Log4j to unpack the intersections where observance of these principles could have mitigated the embedded vulnerabilities. The common principles that were not observed include \emph{fail safe defaults}, \emph{economy of mechanism}, \emph{complete mediation} and \emph{least privilege}. Then we explore the literature on secure software development interventions for developers to identify usable analysis tools and frameworks that can contribute towards improved observance of these principles. We focus on a system wide view of access of codes, checking access paths and aiding application developers with safe libraries along with an appropriate security task list for functionalities.

cs.SE↗

arXiv2022

From Utility to Capability: A New Paradigm to Conceptualize and Develop Inclusive PETs

The wider adoption of PETs has relied on usability studies, which focus mainly on an assessment of how a specified group of users interface, in particular contexts, with the technical properties of a system. While human centred efforts in usability aim to achieve important technical improvements and drive technology adoption, a focus on the usability of PETs alone is not enough. PETs development and adoption requires a broadening of focus to adequately capture the specific needs of individuals, particularly of vulnerable individuals and or individuals in marginalized populations. We argue for a departure, from the utilitarian evaluation of surface features aimed at maximizing adoption, towards a bottom up evaluation of what real opportunities humans have to use a particular system. We delineate a new paradigm for the way PETs are conceived and developed. To that end, we propose that Amartya Sen s capability approach offers a foundation for the comprehensive evaluation of the opportunities individuals have based on their personal and environmental circumstances which can, in turn, inform the evolution of PETs. This includes considerations of vulnerability, age, education, physical and mental ability, language barriers, gender, access to technology, freedom from oppression among many important contextual factors.

cs.CY↗