現行醫療保險理賠申請流程相當繁複，被保險人需要向醫療機構申請診斷證明，填具理賠申請書向保險公司提出理賠申請，再由保險公司進行審核。若遇到無法從診斷書直接審核之個案，保險公司需先取得被保險人簽署之調閱病歷同意書後，方能至醫療機構調閱病歷，以利後續理賠審核。這樣的流程，對保險公司來說，需耗費大量人工成本；對被保險人來說，則也有資訊不夠透明的疑慮。 區塊鏈的運作有著公開透明，且難以造假的不可否認性。智能合約是在區塊鏈平台上執行的協議落實程式，既能確保程式不會被竄改，又可保留所有執行紀錄。若能透過這些特性來做為醫療保險理賠傳遞訊息的媒介，除了能提昇保險公司審核流程的時效性，被保險人也能獲得公開透明的資訊。 本論文提出了一套基於智能合約來實現快速醫療保險理賠的方案，我們在以太坊上實作智能合約，我們的方案除了能改善現有的問題，也建構出一套公開透明，且兼顧病人隱私的理賠系統，並考量實際狀況，讓保險公司的業務邏輯可以重用，在理想與現實之間取得一個適當之平衡點。 / Current medical insurance claims application process is complex. It requires the insured to apply for medical diagnosis, and to fill out an application form to the insurance company. The insurance company then reviews the case. If they are unable to approve the claims, they must first obtain the consent form from the insured in order to access to his or her medical records to facilitate subsequent claims review. Throughout the process, the insurance company needs to pay a lot of labor costs; while the insured will have many concerns of information transparency. Blockchain operates in an open and transparent manner and maintains its data in a tamper-free way. Smart contracts are programs executed on a blockchain platform to enforce an agreement such that the program will not be tampered with, and all records of execution will be kept from modification. These characteristics of a smart contract make it very good as a tool for streamlining the medical insurance claims process, as it will greatly reduce the human efforts involved on the insurance company side while increase the information transparency from the perspective of the insured. This thesis presents a smart contract based solution for streamlining the medical insurance claims process. We design and implement the con-tract on the Ethereum platform. In addition to improving the existing problems, our solution builds an open and transparent claims system that takes into account the patient privacy and the practical requirement of re-using the existing claims processing system of the insurance company, thus achieving a proper balance between the ideal and reality.

近年來區塊鏈技術及其相關應用成為熱門焦點，區塊鏈最大的特色包含去中心化以及匿名性等特性，然而在這樣的分散式網路中我們很難判斷對方是否值得信賴，在數位憑證中我們透過可信賴第三方擔任憑證中心為用戶簽發金鑰憑證以此建立用戶之間的信賴關係，但在區塊鏈此種分散式網路中找到一個可信賴第三方實屬不易，並且可能會與區塊鏈去中心化之特性背道而馳，因此本研究參考PGP信任網與小世界理論的概念，建立一套可適用於分散式環境中基於聲譽的信任度評估機制，並將此機制結合智能合約實現一個信任度評估機制購物平台，目的希望用戶與陌生人交易前，可透過此機制計算出信任度，提供用戶做為參考，幫助用戶更容易判斷陌生人是否可信，以降低受騙風險。 / In recent years, the blockchain technology and its relevant applications become hot spots. The greatest feature of the blockchain is the decentralization. Nonetheless, it is difficult for us to judge whether the other person get involved in the decentralized network is credible. Furthermore, it is difficult to find a reliable third party in such a point-to-point network. Consequently, this paper refers to the PGP web of trust and the small world problem to establish a set of reputation-based trust evaluation mechanism for decentralized environments, we combine this mechanism with a smart contract to achieve a trust evaluation mechanism shopping platform, It is expected that achievements of the paper can facilitate people’s judgment regarding the reliability of strangers and reduce the risks of being deceived.

區塊鏈有著不可否認性、可追溯性以及共識性等特點，所有的交易內容都會完整的被記錄在區塊鏈上，基於上述幾項特性，我們利用區塊鏈來記錄公開資訊，將私密資料經由分散式秘密共享後再加密存放於智能合約中。其中，智能合約是一個能將交易狀態和交易狀態內嵌於區塊鏈上的應用，透過智能合約作為媒介，我們能夠將加密後的私密資料完整的存放於區塊鏈上，最後經由區塊鏈網路上的節點驗證後，達到資料正確性驗證的目的。 本研究分析現有的電子投票以及電子投標等應用的系統架構後，發現兩者皆存在著可信賴的第三方進行開票及開標的角色，且驗證流程繁瑣，無法提供一個便利性的投票與投標流程。此外，上述兩種應用皆須滿足機密性、不可否認性、匿名性以及可驗證性等安全性質，若能結合區塊鏈與智能合約於上述應用中，將可提升資料的可驗證性以及降低成本的負擔，對參與應用的人而言也能達到公開透明的需求。 因此，本文提出一個分散式架構下的電子投票與投標機制，結合區塊鏈以及智能合約的優點與技術，讓所有參與投票的選民、投標的廠商共同參與驗證與計算，並加強參與者的匿名性、資料傳輸的隱私性、開票與開標階段資料的可信賴性以及可驗證性。 / With the rise of blockchain technology, the core concept of decentralization has gradually drawn attention. In this context, the main objective of this study is to realize more convenient and secure electronic applications with the use of blockchain technology. This research is aimed to design a distributed e-voting and e-bidding system. The core idea is to combine the blockchain technology with secret sharing scheme and homomorphic encryption in order to realize the distributed e-voting and e-bidding application without a trusted third party. The system allows voters to participate in opening phase. It provides a public and transparent process while protecting the anonymity of voter’s and vendor’s identity, the privacy of data transmission and verifiability of data during the opening phase.