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中不可或缺的组成部分。该技术的快速发展有力推动了其在众多应用中的集成。与此同时，区块链——这一极具吸引力的分布式账本技术——在过去几年中已受到学术界与工业界的广泛关注，并正日益广泛应用于货币转账、物联网、医疗健康、物流等多个领域。近年来，研究者开始探讨这两种技术交汇时的利弊以及最佳应用场景。本文综述了关于区块链与生物识别技术融合的技术文献研究，并首次对该融合进行了法律分析，以阐明其挑战与潜力。尽管该融合仍处于起步阶段，且已有大量文献在先进技术框架下探讨具体的区块链应用与解决方案，本文仍从整体视角阐述了区块链在生物识别领域的适用性。研究表明，区块链与生物识别技术的结合将有利于推动生物识别领域的新型应用，如PKI机制、分布式可信服务与身份管理。然而，现阶段的区块链网络对于实时应用而言尚不够高效与经济。从法律角度看，责任归属仍是核心问题，同时亦存在其他难点，例如如何实施恰当的数据保护影响评估。最后，本文提出了技术与法律建议，以期在充分发挥融合优势的同时降低相关风险。