58 citations · 194 across the 21 of their papers we have counts for
21 papers · 1 filter
No Country for Old Privacy: The Evolving Challenges of Anonymity in Bitcoin
Ben Hawkins, Joshua Levett, Siamak F. Shahandashti
We present a longitudinal measurement study on the adoption of detectable, second-generation anonymisation protocols in the Bitcoin network, including CoinJoin, CoinSwap, CoinShuff…
Spinel: A Post-Quantum Signature Scheme Based on Hashing
Asmaa Cherkaoui, Faraz Heravi, Delaram Kahrobaei +1
The advent of quantum computation compels the cryptographic community to design digital signature schemes whose security extends beyond the classical hardness assumptions. In this…
Carbyne: An Ultra-Lightweight DoS-Resilient Mempool for Bitcoin
Hina Binte Haq, Syed Taha Ali, Asad Salman +2
The increasing adoption of cryptocurrencies has significantly amplified the resource requirements for operating full nodes, creating substantial barriers to entry. Unlike miners, w…
The Emperor is Now Clothed: A Secure Governance Framework for Web User Authentication through Password Managers
Ali Cherry, Konstantinos Barmpis, Siamak F. Shahandashti
Existing approaches to facilitate the interaction between password managers and web applications fall short of providing adequate functionality and mitigation strategies against pr…
The Effect of Length on Key Fingerprint Verification Security and Usability
Dan Turner, Siamak F. Shahandashti, Helen Petrie
In applications such as end-to-end encrypted instant messaging, secure email, and device pairing, users need to compare key fingerprints to detect impersonation and adversary-in-th…
SPDH-Sign: towards Efficient, Post-quantum Group-based Signatures
Christopher Battarbee, Delaram Kahrobaei, Ludovic Perret +1
In this paper, we present a new diverse class of post-quantum group-based Digital Signature Schemes (DSS). The approach is significantly different from previous examples of group-b…
A Subexponential Quantum Algorithm for the Semidirect Discrete Logarithm Problem
Christopher Battarbee, Delaram Kahrobaei, Ludovic Perret +1
Group-based cryptography is a relatively unexplored family in post-quantum cryptography, and the so-called Semidirect Discrete Logarithm Problem (SDLP) is one of its most central p…
Semidirect Product Key Exchange: the State of Play
Christopher Battarbee, Delaram Kahrobaei, Siamak F. Shahandashti
Of the many families of cryptographic schemes proposed to be post-quantum, a relatively unexplored set of examples comes from group-based cryptography. One of the more central sche…
On the efficiency of a general attack against the MOBS cryptosystem
Christopher Battarbee, Delaram Kahrobaei, Dylan Tailor +1
All instances of the semidirect key exchange protocol, a generalisation of the famous Diffie-Hellman key exchange protocol, satisfy the so-called "telescoping equality"; in some ca…
Cryptanalysis of Semidirect Product Key Exchange Using Matrices Over Non-Commutative Rings
Christopher Battarbee, Delaram Kahrobaei, Siamak F. Shahandashti
It was recently demonstrated that the Matrix Action Key Exchange (MAKE) algorithm, a new type of key exchange protocol using the semidirect product of matrix groups, is vulnerable…
Accept All: The Landscape of Cookie Banners in Greece and the UK
Georgios Kampanos, Siamak F. Shahandashti
Cookie banners are devices implemented by websites to allow users to manage their privacy settings with respect to the use of cookies. They are part of a user's daily web browsing…
Formal Modelling and Security Analysis of Bitcoin's Payment Protocol
Paolo Modesti, Siamak F. Shahandashti, Patrick McCorry +1
The Payment Protocol standard BIP70, specifying how payments in Bitcoin are performed by merchants and customers, is supported by the largest payment processors and most widely-use…
Revisiting Security Vulnerabilities in Commercial Password Managers
Michael Carr, Siamak F. Shahandashti
In this work we analyse five popular commercial password managers for security vulnerabilities. Our analysis is twofold. First, we compile a list of previously disclosed vulnerabil…
Battery draining attacks against edge computing nodes in IoT networks
Ryan Smith, Daniel Palin, Philokypros P. Ioulianou +2
Many IoT devices, especially those deployed at the network edge have limited power resources. A number of attacks aim to exhaust these resources and drain the batteries of such edg…
DOMtegrity: Ensuring Web Page Integrity against Malicious Browser Extensions
Ehsan Toreini, Maryam Mehrnezhad, Siamak F. Shahandashti +1
In this paper, we address an unsolved problem in the real world: how to ensure the integrity of the web content in a browser in the presence of malicious browser extensions? The pr…
A New Look at the Refund Mechanism in the Bitcoin Payment Protocol
Sepideh Avizheh, Reihaneh Safavi-Naini, Siamak F. Shahandashti
BIP70 is the Bitcoin payment protocol for communication between a merchant and a pseudonymous customer. McCorry et al. (FC~2016) showed that BIP70 is prone to refund attacks and pr…
Analysing and Patching SPEKE in ISO/IEC
Feng Hao, Roberto Metere, Siamak F. Shahandashti +1
Simple Password Exponential Key Exchange (SPEKE) is a well-known Password Authenticated Key Exchange (PAKE) protocol that has been used in Blackberry phones for secure messaging an…
Texture to the Rescue: Practical Paper Fingerprinting based on Texture Patterns
Ehsan Toreini, Siamak F. Shahandashti, Feng Hao
In this paper, we propose a novel paper fingerprinting technique based on analyzing the translucent patterns revealed when a light source shines through the paper. These patterns r…
Stealing PINs via Mobile Sensors: Actual Risk versus User Perception
Maryam Mehrnezhad, Ehsan Toreini, Siamak F. Shahandashti +1
In this paper, we present the actual risks of stealing user PINs by using mobile sensors versus the perceived risks by users. First, we propose PINlogger.js which is a JavaScript-b…
TouchSignatures: Identification of User Touch Actions and PINs Based on Mobile Sensor Data via JavaScript
Maryam Mehrnezhad, Ehsan Toreini, Siamak F. Shahandashti +1
Conforming to W3C specifications, mobile web browsers allow JavaScript code in a web page to access motion and orientation sensor data without the user's permission. The associated…
A Verifiable Partial Key Escrow, Based on McCurley Encryption Scheme
Kooshiar Azimian, Javad Mohajeri, Mahmoud Salmasizadeh +1
In this paper, firstly we propose two new concepts concerning the notion of key escrow encryption schemes: provable partiality and independency. Roughly speaking we say that a sche…