The right to personal privacy is known as a fundamental human right allowing people to restrict access to their personal information. The decentralized nature of blockchain networks, often involving the publicity of ledger information, can come into conflict with this right. This is in particular the case when the blockchain maintains sensitive information such as financial credits or medical information. In this paper, we discuss this interaction. We first describe multiple aspects of privacy such as its practical limit towards authorities, its potential vulnerability, and its association with technological systems such as blockchain networks. Towards answering these challenges, we survey a wide range of techniques relying on tools from the areas of cryptography, distributed system, and hardware architecture. We explain how each can be used to enhance privacy in blockchain networks following their unique nature. We further conclude that none of the available techniques can fully answer the complex practical requirements, and that practical solutions should combine both centrally controlled and decentralized systems.

个人隐私权被称为一项基本人权，允许人们限制对其个人信息的访问。区块链网络的去中心化性质，通常涉及账本信息的公开，可能与这一权利发生冲突。当区块链维护敏感信息（例如金融信用或医疗信息）时尤其如此。在本文中，我们将讨论这种相互作用。我们首先描述隐私的多个方面，例如它对当局的实际限制、它的潜在脆弱性以及它与区块链网络等技术系统的关联。为了应对这些挑战，我们调查了广泛的技术，这些技术依赖于密码学、分布式系统和硬件架构领域的工具。我们解释了每个方法如何根据其独特的性质来增强区块链网络的隐私。我们进一步得出结论，没有一种可用的技术可以完全满足复杂的实际要求，实用的解决方案应该结合中央控制和分散系统。