當證據「上鏈」：論區塊鏈科技應用於法庭證據

Blockchain Technology and Courtroom Evidence

區塊鏈是法律與科技領域最受矚目的議題之一，與證據法則關係密切。本文旨在探討區塊鏈證據對於刑事審判將帶來何種衝擊，法院又應以何種證據法則處理區塊鏈證據。本文第一至三章闡述區塊鏈的意義與技術，指出區塊鏈的2項技術特徵：「去中心化」和「不可竄改」，與證據法則追求證據真實性的基本價值相合。繼而分析不同類型的證據儲存於區塊鏈（「上鏈」）的利益和風險，說明何種證據類型較適合「上鏈」及其原因。第四至五章探討與數位證據有關的2項證據法則：傳聞與驗真，如何應用於區塊鏈證據。由於美國已有針對區塊鏈證據的明文規範，以及可能適用的法院判決，本文參考美國法的規範與實務，在第四章討論區塊鏈證據是否為傳聞或傳聞例外、標準判斷何在等議題；第五章說明驗真法則的意義、要件、如何應用於區塊鏈證據等議題。第六章討論我國法院操作區塊鏈證據可能遭遇的困難。包括法院傾向認為數位證據有證據能力、未能依證據的本質進行調查、區塊鏈證據適用傳聞例外及驗真程序的可能等。本文在探討上述各項議題時，均舉我國法院的具體案件，或司法機關的區塊鏈應用政策為例進行分析，並借鏡對於區塊鏈證據討論相對豐富的美國法制，希望作為我國立法和實務運作的參考。

Blockchain technology is one of the trendiest topics in the field of law and technology, particularly in regard to evidence law. This article explores how blockchain technology would change and influence the practices of criminal courts, and how the court may adapt the existing evidentiary principles to the issues brought about by this new technology. In Chapter I and II, this article introduces what a blockchain is, and its fundamental technical characteristics. It asserts there are two core characteristics of blockchains, decentralization and immutability, which resonate with the fundamental pursuit of evidential principles. In Chapter III, this article analyzes the pros and cons of storing evidence in blockchain network (“being blockchain-ed”). I will illustrate major concerns and risks which policy makers and legal professionals should consider when it comes to blockchain-ed evidence. Then, this article turns to a discussion about the connection between the emerging use of blockchain technology and the existing evidentiary principles in Chapter IV, V, and VI. The Chapter IV studies whether blockchain evidence is hearsay, because it may involve the reproduction of a person’s statement, in this case, by computer. Different from what most of the literature argues, either for or against the concept that blockchain evidence is hearsay, this article contends that we should first clarify how blockchain technology is being used. Chapter V talks about another evidence law issue: authentication. Authentication is usually not a very tough requirement to satisfy in most cases involving exhibits, but it may be complicated with regard to blockchain evidence. The proponent of blockchain evidence should provide information to describe what a blockchain is and how it works, and show that it produces an accurate result. In Chapter VI, this article attempts to predict how blockchain evidence may be used in Taiwan’s criminal courts, by examining how courts in Taiwan have used other types of digital evidence. Previous court decisions show that courts are inclined to make digital evidence admissible, based on the belief that it has higher probative value than traditional exhibits or testimony due to an unwarranted faith in technology. This article describes concerns about this inclination towards admissibility, because it seems the belief of courts does not have a solid foundation.