Exchange of information through the web took place inside a trusted environment and thus user privacy was assured by default. Nowadays, ensuring user privacy is becoming one of the most desirable features of new technology, and Blockchain is not an exception. The Blockchain is a decentralized technology, open, and public platform where all transactions are stored and viewed from nodes, an approach known as "Web of Trust." Although these transactions tend to be anonymous but in the case of the banking sector, user privacy requires special attention. In centralized systems, the implementation of privacy is no longer a challenge, using a hierarchical approach such as Public Key Infrastructure. This paper presents a broad landscape and state of art of user transaction privacy in Blockchain technology using the Web of Trust approach. Furthermore, we present a novel approach using the Public Key Infrastructure for assuring user privacy adding an optionally encrypted field in blocks in transactions. We have used Bithomp, as a free and open-source tool with the Testnet platform, and Ripple as the best known in the implementation of the payment system to implement the proposed approach. The paper concludes with the strengths and limitations of the proposed approach. [ABSTRACT FROM AUTHOR]