近年來，安全電子商務協議的設計和分析逐漸成為熱點。機密性、公平性等性質是衡
量電子商務協議安全與否的重要標志，也是協議能否順利使用的重要前提。機密性和公平性是安全電子商務協議的基本性質，但可證實電子郵件協議CMP 作為電子商務協議的一種卻并不滿足這些性質。該文指出可證實電子郵件協議CMP 的幾個缺陷，對其分析并提出了改進方案，改進后的協議滿足了機密性和公平性。
關鍵詞：安全電子商務協議；機密性；公平性；可證實電子郵件協議
Limitations and improvement of CMP XI Lin, ZHAO Dong-Ming (School of Information & Engineering, Zhengzhou University, Zhengzhou Henan 450052, China) Abstract: There is a growing interest in the design and analysis of electronic commerce protocols. Both confidentiality and fairness are important in electronic commerce protocols，but Certified
electronic mail protocol (CMP), as a kind of electronic commerce protocol, does not have such
crucial qualities. So several limitations of the CMP are pointed out and the improved measure is put forward. The improved one satisfies both confidentiality and fairness.
Key words: electronic commerce protocol; confidentiality; fairness; Certified electronic mail
protocol