Biometric recognition as a unique, hard-to-forge, and efficient way of identification and verification has become an indispensable part of the current digital world. The fast evolution of this technology has been a strong incentive for integrating it into many applications. Meanwhile, blockchain, the very attractive decentralized ledger technology, has been widely received both by the research and industry in the past years and it is being increasingly deployed nowadays in many different applications, such as money transfer, IoT, healthcare, or logistics. Recently, researchers have started to speculate what would be the pros and cons and what would be the best applications when these two technologies cross paths. This paper provides a survey of technical literature research on the combination of blockchain and biometrics and includes a first legal analysis of this integration to shed light on challenges and potentials. While this combination is still in its infancy and a growing body of literature discusses specific blockchain applications and solutions in an advanced technological set-up, this paper presents a holistic understanding of blockchains applicability in the biometric sector. This study demonstrates that combining blockchain and biometrics would be beneficial for novel applications in biometrics such as the PKI mechanism, distributed trusted service, and identity management. However, blockchain networks at their current stage are not efficient and economical for real-time applications. From a legal point of view, the allocation of accountability remains a main issue, while other difficulties remain, such as conducting a proper Data Protection Impact Assessment. Finally, it supplies technical and legal recommendations to reap the benefits and mitigate the risks of the combination.

翻译：生物识别作为一种独特、难以伪造且高效的身份识别与验证方式，已成为当前数字世界不可或缺的组成部分。该技术的快速发展极大地推动了其在众多应用中的集成。与此同时，区块链这种极具吸引力的去中心化账本技术，在过去数年间已获得研究界和工业界的广泛认可，并越来越多地部署于资金转账、物联网、医疗保健或物流等多种应用场景。近期，研究者开始探讨这两种技术交叉融合时的利弊及最佳应用场景。本文对区块链与生物识别相结合的技术文献研究进行了综述，并首次从法律角度分析这种融合，以揭示其挑战与潜力。尽管这一结合仍处于初级阶段，且不断增长的文献探讨了特定区块链应用与先进技术方案，本文旨在提供区块链在生物识别领域适用性的整体理解。研究表明，区块链与生物识别的结合将有利于生物识别领域的新应用，如公钥基础设施（PKI）机制、分布式可信服务及身份管理。然而，当前阶段的区块链网络对于实时应用而言效率不足且经济性不佳。从法律视角看，责任归属仍是主要问题，此外还存在其他难题，例如如何进行适当的数据保护影响评估。最后，本文提出了技术与法律两方面的建议，以充分利用该结合的优势并降低相关风险。