On July 9th, 2026, we cordially invite you to the next SBA Security Afterworks event!
You can look forward to informative and engaging presentations, lively discussions, and a relaxed get-together to wrap up the evening with experts, partners, and industry colleagues.
Three keynote impulses will frame and stimulate the discussion:
Talk 1: Reuse of Public Keys Across UTXO and Account-Based Cryptocurrencies – Nicholas Stifter
It is well known that reusing cryptocurrency addresses undermines privacy. This also applies if the same addresses are used in different cryptocurrencies. Nevertheless, cross-chain address reuse appears to be a recurring phenomenon, especially in EVM-based designs. Previous works performed either direct address matching, or basic format conversion, to identify such cases. However, seemingly incompatible address formats e.g., in Bitcoin and Ethereum, can also be derived from the same public keys, since they rely on the same cryptographic primitives.
In this paper, we therefore focus on the underlying public keys to discover reuse within, as well as across, different cryptocurrency networks, enabling us to also match incompatible address formats. Specifically, we analyze key reuse across Bitcoin, Ethereum, Litecoin, Dogecoin, Zcash and Tron. Our results reveal that cryptographic keys are extensively and actively reused across these networks, negatively impacting both privacy and security of their users. We are hence the first to expose and quantify cross-chain key reuse between UTXO and account-based cryptocurrencies. Moreover, we devise novel clustering methods across these different cryptocurrency networks that do not rely on heuristics and instead link entities by their knowledge of the underlying secret key.
Talk 2: Traceable Data Sharing: Protecting Structured Data with Fingerprints – Tanja Šarčević
Data sharing is essential for collaboration, innovation, and machine learning, but it also creates a critical governance challenge: once data leaves the owner’s environment, unauthorized redistribution is difficult to detect and attribute. This presentation introduces NCorr-FP, a neighbourhood-based, correlation-preserving fingerprinting approach for intellectual property protection of structured data.
NCorr-FP embeds a hidden, recipient-specific identifier directly into each shared dataset while aiming to preserve the statistical properties that make the data useful.
The presentation explains the practical motivation and the main technical idea. It also summarizes experimental evidence showing that fingerprinted data remains statistically close to the original, and continues to support downstream machine learning with limited performance degradation. The result is a practical mechanism for accountable data sharing in environments where both collaboration and control matter.
Talk 3: Lessons Learned from Securing AI-first Software Development – Thomas Konrad
As part of the traditional relaxed closing session, there will be plenty of opportunities to network and exchange ideas.
About the Speakers
Nicholas Stifter is a researcher and security analyst at SBA Research. His work focuses on the security, sustainability, and core principles of distributed ledger and blockchain technologies. Nicholas holds degrees in Computer Science Management and Software Engineering from TU Wien and is currently pursuing a PhD on governance, security, and maintainability in distributed ledger technologies and smart contracts. His research interests include Nakamoto consensus, distributed agreement protocols, and computing education for distributed systems.
Tanja Šarčević received a bachelor´s degree in Computer Science from the University of Zagreb and a master´s degree in Logic and Computation at the TU Wien. She is currently working towards her PhD degree with the focus on ownership protection of data and machine learning models.
Registration
Please register via forms.
About the Security Afterworks
The Security Afterworks serve as a forum for exchanging ideas and networking among security professionals. Held at irregular intervals, these events combine expert discussions and knowledge sharing with an opportunity to connect and unwind with colleagues in an informal setting afterwards.
This event is hosted by the Vienna ACM SIGSAC Chapter.