物聯網時代來臨，面對多元的訊息交換環境，需要更方便且更安全的訊息交換機制來保護訊息安全，傳統對稱式金鑰雖然可以達到運算速度快的效能，卻無法同時完成簽章及驗證作業。倘若有一種非對稱式金鑰的演算機制，設計上更輕量化，在運算效能上能與傳統對稱式媲美，且能同時完成簽章及驗證作業，將會使訊息保護機制更安全，並且足夠抵擋網路上常見的攻擊。因此本研究提出一個利用橢圓曲線密碼及隨機背包密碼為概念的混合式加密新方法，具有除了符合機密性、可驗證性及不可否認性等基本安全需求外，尚可應付網路上常見的攻擊方式。本研究具有以下三項優點：(1)建立一個運算速度快，耗費資源小的輕量化混合式加密系統執行訊息保護及交換模式(2)建置快速及安全的可離線身分認證機制，並且於通訊階段不需要線上認證中心參與認證(3)符合機密性、完整性、鑑別性及不可否認性等基本安全需求。

With the prosperous development of Internet of Thing, we are in face of a variety information exchange environment, we need a more convenient and more secure message exchange scheme to protect the message security. Although the traditional symmetric cryptosystem can achieve the better performance on computing, we still cannot complete the signature and verification at the same time. If we can design a scheme that using an asymmetric cryptosystem, and the design is more lightweight, good computational performance, and can comparable with the traditional symmetric cryptosystem, and can complete the signature and verification at the same time, it will make the message protection mechanism safer, and enough resist the common attacks on the Internet. Therefore, this study proposes a new hybrid encryption method based on elliptic curve cryptography and random knapsack cryptosystem, which can afford of the security requirements such as confidentiality, verifiability and non-repudiation, and can still resist the common attacks on the Internet. This research has the following three advantages: (1) Establishing a lightweight hybrid cryptosystem with good performance on computing and using limited resources on message protection and key exchange (2) Establishing a fast and secure self-certification authentication mechanism and during communication phase we do not require online Certification Authority, CA, to take part in (3) Can achieve the Confidentiality, integrity, identification and non-repudiation of the basic security needs.