密碼學發展至今,可歸納出三大類的密碼系統.第一類為對稱金匙密碼
系統,第二類為非對稱金匙密碼系統或簡稱公開金匙密碼系統.第三類為金
匙信託或金匙回復密碼系統. 雖然為了資訊安全的理由而對通訊資料
加密,然而相對地,不法份子也可利用其來反制政府的監控,藉由密碼系統
之協助,可以對其非法行為進行秘密通訊而逍遙法外,為了防止上述問題的
發生,"金匙信託加密系統"的概念便應運而生,同時也造成其他國家對此之
重視,尤其受到公,商業界的期待與青睞,因此"金匙信託加密系統"的需求
可見一般,將主導未來加密系統之應用. 吾人將實際模擬出"人機分離
金匙信託加密系統".作時間效能的分析,並且強調執法單位監聽的過程,藉
此實作測試結果(執行回應時間)證明系統理論之實用與可行性,最後提出
系統未來發展目標及其應用發展方向.

As the development of cryptosystems, We summary three main
cryptosystems. The first one is "cryptosystem of symmetric key",
the second one is "crypto -system of asymmetric key"(
cyrptosystem of public key), and the third one is "cryptosystem
of key escrow"(cyrptosystem of key recovery). It is to ensure
the privacy and the security of messages by encrypting the
message of communications. However, Criminals encipher those
message in comm -unications to do some crimes. To prevent the
crises, key escrow system was born. Besides, it is also
appreciated and expected by many countries,especial -ly for
industrial and commercial societies. The necessity of "Key
Escrow Encryption System" is obvious and the applications of
key escrow encryption system should be boomed. We implement
the Key Escrow Encryption System on the individual and the
machine bounds", analyze and evaluate the costs(response time)
of each actions in the system, and prove that the implemented
system is practical and useful. Finally, we conclude the
developments and applications of our system in the future.