近年來，量子理論與量子演算法的發展非常快速。有部份的問題可以非常快速地被量子演算法解決，而這些問題在傳統電腦上是很困難的問題。由於近代加密演算法的安全性是建構在計算困難或是數學難題上，此類演算法將會在量子電腦問世後變得不安全。舉例而言，現今已有可在合數位數之多項式時間內分解合數成其質因數分解的演算法，這個事實使得包含RSA在內所有建立於大數分解的公開金鑰系統直接成為不安全的系統。然而，在量子的環境之下，其安全性並不是建立在於計算安全之上，相對之下，其安全性是直接建立在量子的性質之上，所以有很多的量子密碼學都是基於量子的性質來發展設計。
當我們想要藉由網路傳遞訊息時，在傳遞的過程會有些在通道上的噪音或雜訊干擾。由於其資訊會被編碼成零與一的串列，雜訊可能會對訊息中的部份位元造成翻轉。在一般情形下，人們都是使用錯誤檢查碼來避免這種錯誤發生。由於量子系統的一些特性，如果我們需要藉由傳遞光子(或是量子)傳送資料，那麼會有多種與一般網路會發生的雜訊不同種類的噪音發生，例如消相干性雜訊，阻抗雜訊，以及振幅雜訊等噪音。
本篇論文將會提出可以抵抗集合雜訊的抗消相干雜訊量子態，與可分辨出相異量子態之量測方法以更有效率的方法來做傳輸。本論文會使用量子金鑰分配協定來做為應用展示抗消相干雜訊量子態。

The recent development of quantum theory and quantum algorithms has occurred rapidly. Certain problems can be solved quickly by using quantum algorithms, which are considered difficult problems when using classical computers. Because the security of modern cryptography relies on the computational difficulty of mathematical problems, it is given compromised by the availability of the quantum computer. For example, a quantum algorithm can factor a composite number in polynomial time of digits of chosen composite number. This result causes all the protocols to rely on the difficulty of large number decomposition, including the RSA public key system, causing insecurity. However, in the quantum environment, security does not rely on computational difficulty, but on the quantum property. Therefore, an abundance of quantum cryptography has been developed using the quantum property.
Transporting information through the Internet incurs certain channel noise during transmission. Because the information is encoded as a sequence of 0s and 1s, channel noise may flip bits of information during transmission. People typically use error correction code (ECC) to avoid errors. Because of quantum system properties, transmitting data through transport photons, called quantum bits (qubits), results in certain types of noises that differ from that using classical channel. For example, collective noise and amplitude noise are noises in quantum channel.
This thesis proposes decoherence-free states to negate decoherence noise, using a distinguishable measurement method for more efficient transport, and applies a Quantum Key Distribution (QKD) protocol to demonstrate the usage of
decoherence-free state.

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