Filip Rezabek

Mostafa Abdelrahman, Filip Rezabek, Lars Hupel et al.

Digital signatures are crucial for securing Central Bank Digital Currencies (CBDCs) transactions. Like most forms of digital currencies, CBDC solutions rely on signatures for transaction authenticity and integrity, leading to major issues in the case of private key compromise. Our work explores threshold signature schemes (TSSs) in the context of CBDCs. TSSs allow distributed key management and signing, reducing the risk of a compromised key. We analyze CBDC-specific requirements, considering the applicability of TSSs, and use Filia CBDC solution as a base for a detailed evaluation. As most of the current solutions rely on ECDSA for compatibility, we focus on ECDSA-based TSSs and their supporting libraries. Our performance evaluation measured the computational and communication complexity across key processes, as well as the throughput and latency of end-to-end transactions. The results confirm that TSS can enhance the security of CBDC implementations while maintaining acceptable performance for real-world deployments.

Filip Rezabek, Dahlia Malkhi, Amir Yahalom

The emergence of decentralized satellite networks creates a pressing need for trust architectures that operate without physical access to hardware, without pre-provisioned vendor secrets, and without dependence on a single manufacturer's attestation service. Terrestrial TEEs are insufficient: hardware-based designs are susceptible to physical attacks, and most platforms root their attestation chains in secrets provisioned during manufacturing, creating a pre-launch trust window and single-vendor dependency that cannot be independently audited. We present Space Fabric, an architecture that provides the missing trust foundation for orbital computing by relocating the trusted computing stack to satellite infrastructure, exploiting post-launch physical inaccessibility as a tamper barrier unattainable by terrestrial deployments. Our Satellite Execution Assurance Protocol binds workload execution to a specific satellite via a Byzantine-tolerant endorsement quorum of distributed ground stations, certifying not only \emph{what} executes inside the TEE but also \emph{where}. All cryptographic secrets are generated within co-located secure elements after launch, with no signing keys accessible on Earth at any point. To reduce single-vendor dependence, Space Fabric distributes its trust anchor across two independent secure elements, an NXP SE050 and a TROPIC01, both of which must co-sign attestation evidence. We implement Space Fabric on a USB Armory Mk II with ARM TrustZone, verify attestation end-to-end using Veraison, and provide a security analysis with satisfaction arguments and impossibility bounds under a strong adaptive adversary.

Tiago Espinha Gasiba, Kristian Beckers, Santiago Suppan et al.

Teaching industry staff on cybersecurity issues is a fundamental activity that must be undertaken in order to guarantee the delivery of successful and robust products to market. Much research attention has been devoted to this topic over the last years. However, the research which has been done has not focused on developing secure code in industrial environments. In this paper we take a look at the constraints and requirements for delivering a training, by means of cybersecurity challenges, that covers secure coding topics from an industry perspective. Using requirements engineering, we aim at understanding the design requirements for such challenges. Along the way, we give details on our experience of delivering cybersecurity challenges in an industrial setting and show the outcome and lessons learned. The proposed requirements for cybersecurity challenges geared towards software developers in an industrial environment are based on systematic literature review, interviews with security experts from the industry and semi-structured evaluation of participant feedback.