arXiv subjects

Antoaneta Serguieva

Publications and source records attributed to Antoaneta Serguieva.

3 recordsLinked to original sources

arXiv2018

The Evolution of Embedding Metadata in Blockchain Transactions

The use of blockchains is growing every day, and their utility has greatly expanded from sending and receiving crypto-coins to smart-contracts and decentralized autonomous organizations. Modern blockchains underpin a variety of applications: from designing a global identity to improving satellite connectivity. In our research we look at the ability of blockchains to store metadata in an increasing volume of transactions and with evolving focus of utilization. We further show that basic approaches to improving blockchain privacy also rely on embedding metadata. This paper identifies and classifies real-life blockchain transactions embedding metadata of a number of major protocols running essentially over the bitcoin blockchain. The empirical analysis here presents the evolution of metadata utilization in the recent years, and the discussion suggests steps towards preventing criminal use. Metadata are relevant to any blockchain, and our analysis considers primarily bitcoin as a case study. The paper concludes that simultaneously with both expanding legitimate utilization of embedded metadata and expanding blockchain functionality, the applied research on improving anonymity and security must also attempt to protect against blockchain abuse.

cs.CR↗

arXiv2018

Sustainable blockchain-enabled services: Smart contracts

This chapter contributes to evolving the versatility and complexity of blockchain-enabled services through extending the functionality of blockchain-enforced smart contracts. The contributions include: (i) a method for automated management of contracts with hierarchical conditionality structures through an hierarchy of intelligent agents and the use of hierarchical cryptographic key-pairs; (ii) a method for efficient and secure matching and transfer of smart- contract underlyings (entities) among disparate smart contracts/subcontracts; (iii) a method for producing an hierarchy of common secrets to facilitate hierarchical communication channels of increased security in the context of smart contracts/subcontracts/underlyings; and (iv) a method for building secure and optimized repositories through distributed hash tables in the context of contracts/ subcontracts/underlyings. These methods help providing services that allow both narrower and worldwide reach and distribution of resources. The longevity of the blockchain technology is achieved through continuous innovation. Blockchain-enabled services are potentially an efficient, secure, automated, and cost-effective alternative or complement to current service infrastructures in a range of domains (legal, medical, financial, government, IoT).

cs.CR↗

arXiv2017

Multichannel Contagion vs Stabilisation in Multiple Interconnected Financial Markets

The theory of multilayer networks is in its early stages, and its development provides vital methods for understanding complex systems. Multilayer networks, in their multiplex form, have been introduced within the last three years to analysing the structure of financial systems, and existing studies have modelled and evaluated interdependencies of different type among financial institutions. These studies, however, have considered the structure as a non-interconnected multiplex - an ensemble of single layer networks comprising the same nodes - rather than as an interconnected multiplex network. No mechanism of multichannel contagion has been modelled and empirically evaluated, and no multichannel stabilisation strategies for pre-emptive contagion containment have been designed. This paper formulates an interconnected multiplex structure, and a contagion mechanism among financial institutions due to bilateral exposures arising from institutions activity within different interconnected markets that compose the overall financial market. We introduce structural measures of absolute systemic risk and resilience, and relative systemic-risk indexes. Based on the contagion mechanism and systemic-risk quantification, this study designs minimum-cost stabilisation strategies that act simultaneously on different markets and their interconnections, in order to effectively contain potential contagion progressing through the overall structure. The stabilisation strategies subtly affect the emergence process of structure to adaptively build in structural resilience and achieve pre-emptive stabilisation at a minimum cost for each institution and at no cost for the system as a whole. We empirically evaluate the new approach using large granular databases, maintained by the Prudential Regulatory Authority of the Bank of England. The capabilities of multichannel stabilisation are confirmed empirically.

q-fin.CP↗