Quantum Cryptography: Oblivious Transfer and Key Agreement

[[abstract]]近幾年因為量子物理的崛起，越來越多科學家將心力投注在量子相關領域的發展，科學家們發現可以利用量子的特性來發展量子電腦，量子電腦擁有驚人的計算力，能夠在短時間內用量子演算法破解目前常用的非對稱式金鑰系統RSA，也可以加速目前常用的對稱式金鑰系統AES的破譯，如此驚人的計算力，使得各國爭先恐後的發展量子電腦或者量子相關技術，希望能夠藉此成為未來世界的霸權。目前美國幾個主要大公司如Google、IBM、Microsoft等都已開發或投入研發自己的量子電腦，而中國大陸則是專攻量子通訊部分，其已發射墨子號量子衛星，可以在太空中使用量子密碼進行空對地的通訊。 同一時間密碼學家也嘗試尋找或設計新的加密方式以抵禦量子電腦的攻擊，這產生了兩個支脈，分別是後量子密碼學以及量子密碼學，後量子密碼學主要還是使用傳統密碼學來抵禦量子演算法的攻擊，雖這些方法比起主流的密碼學較為無效率，但許多方法都已被證明可以抵禦量子演算法之攻擊；另一支脈為量子密碼學，密碼學家直接利用量子的特性來設計加解密的方式，這使得原本難以達到的絕對安全得以實現，而我的研究主要以量子密碼學為主。 量子密碼學目前主要有四個大支脈，分別為量子金鑰配置、量子安全直接傳輸、量子秘密分享以及量子模糊傳輸，這四個分支主要由傳統密碼學延伸而來，但也有新穎的通訊方式，如量子安全直接傳輸；我在這四個支脈都分別有涉略，接著我會以類似總覽論文的方式帶著各位讀者審視量子密碼學界的發展，並向各位一一介紹我們的發現與成果。[[abstract]]Quantum computer has amazing computational power, can use the quantum algorithm to crack the current commonly used asymmetric key system RSA in a short time, can also accelerate the deciphering of the commonly used sysmmetric key system AES. Such amazing computing power has let countries to rush to develop quantum computers or quantum-related technologiees, hoping to become the hegemony of the future world. At the same time, cryptographers also tried to find or design new encryption methods to defend against the attacks from quantum computer, called post-quantum cryptography and quantum cryptography. Post-quantum cryptography mainly uses classical cryptography to defend against the attacks from quantum algorithms, many methods have been proved to able to resist the attack of quantum algorithms; Another branch is quantum cryptography. Cryptographers directly use the properties of quantum machine to design the way of encryption and decryption, which enables the realization of unconditionally secure. My research is mainly focuses on quantum cryptography. Quantum cryptography currently has four major branches, namely quantum key distribution (QKD), quantum secure direct communication (QSDC), quantum secret sharing (QSS), and quantum oblivious transfer (QOT). These four branches are mainly extended from classical cryptography, but there are also novel ways of communication, such as quantum secure direct communication; I have involved in these four branches. I will then introduce the development of quantum cryptography in a similar way to the overview paper, and describe our findings and research results.[[note]]博