## 1 Introduction
### Background  
In 1991, [PERSON] and [PERSON] [1] proposed a method for date and time stamping digital documents. However, digital documents cannot be time-stamped or authenticated in the same way as paper documents. At the time, the authors proposed a basic structure consisting of hash cryptography (algorithm) that organizes immutable information into linked blocks. An authentication service organizes the documents or blocks of information sequentially, according to date and time. The spreading of encrypted information among different clients (companies or people) guarantees that recorded data cannot be altered without leaving traces [2]. In this flow of information, first, if a client wants to falsify previously registered information,the authentication service can check the previous record and identify the fraud attempt. Second, suppose the authentication service itself conspires with a forger to try to falsify previously recorded information, in that case, he/she cannot do it without leaving traces, since the information is distributed among the other clients that will be able to audit the forgery [1]. In other words, even if a client and the authentication service are dishonest and act together to create fraud, the other clients can identify it. So, the technology works like a logbook that can keep permanent data records about decisions and transactions [3]. Since it is composed of blocks of information in a chain, the technology started to be called the 'blockchain'. Blockchain technology is becoming efficient, robust, and cost-effective for managing interactions between multiple participants in a network, in a very reliable and decentralized manner [4; 5]. Likewise, it facilitates the use of information by subsidizing demands and providing the real-time updating of records. It also increases supply chain transparency and product or service traceability by allowing the exchange of transactional data between two or more actors in the chain [6]. This is because data stored in the blockchain is reliable and cannot be deleted, altered, or corrupted, without most parties involved in the transaction being aware of the changes. Blockchain is considered a significant technological trend that could influence business in general, as it is a disruptive solution for several business segments capable of increasing the trust of bilateral or multilateral relationships [6]. Thus, blockchain could create competitive advantages in many business sectors, especially agribusiness. [PERSON] et al. [7] point out several blockchain applications in agribusiness activities, such as finance, energy, logistics, environmental management, agriculture, livestock, and agro-industry. According to the authors, blockchain can be successfully implemented, and applications for logistics can result in energy, financial and environmental advantages. Agribusiness comprises long supply chains involving various economic sectors, and fundamental activities such as providing food and energy for the human and animal populations. As end-consumers seek more information about product quality, origin, and mode of production, company managers, supply chains, and governments, are pressured to adopt solutions that ensure product transparency and traceability [8; 9]. In agribusiness, blockchain technology can be applied in solutions to ensure the security and traceability of products in a system in which information is transmitted between all links and actors along the value chain. Information sharing allows for building trust and transparency between actors. Consumers can trace products to check their origin and production mode, hindering the possibilities of product counterfeiting and adulteration [7; 10]. Thus, a traceability system based on blockchain brings benefits and information to all those involved in the supply chain, including the final consumers [11; 12; 13], since it enables the use and exchange of data in a secure, transparent, and effective manner [14].