量子網路中的資訊處理仰賴對節點間量子關聯與各節點量測裝置的可靠描述。然而，當糾纏光源與部分量測裝置無法完全信任時，此類描述將面臨根本性的困難。此困難在網路情境中更為明顯：單一光源將糾纏分發給信任程度不同的多個節點，僅有狀態的製備並不足以確定實際抵達每一個量測裝置的狀態。傳統的量測裝置斷層掃描利用一組完備的已知輸入態及其量測結果機率，求得未知量測裝置的正算子值測度（positive operator-valued measure, POVM）元素。本論文提出並實驗實現「操控性驗證之不可信量測裝置斷層掃描（steering-verified untrusted measurement device tomography, SV-UMDT）架構。在此架構中，不可信光源將多體糾纏分發給一個可信量測節點與多個不可信量測節點，並由古典驗證者詢問並記錄各方於指定基底的量測結果。本論文透過純多體 Einstein--Podolsky--Rosen（EPR）操控性，為遠端製備的斷層掃描輸入態提供驗證依據，從而釋放傳統方法對可信輸入態的假設。純多體操控性目擊的違反排除了所有二分割下預先存在的古典描述，使操控性驗證涵蓋整個多方網路，確立各不可信節點同屬於一個多體關聯。經此驗證的輸入態及其量測結果機率，可分別求得各不可信量測裝置的有效 POVM 元素，並應用於量子同調性認證及理論層面的量子隨機數生成。於量子同調性認證中，不可信裝置的量測算符共同為遠端製備的目標態給出同調性下界。於量子隨機數生成中，各不可信裝置的輸出各自提供隨機性來源，所得的量測參數則界定各方於古典側資訊下可萃取的隨機性。依此模型認證的隨機位元，可作為建構於同一光源上之多方任務中參與方各自所需的隨機性資源。本方案於多光子糾纏平台上完成實驗展示，實現純多體操控性驗證、不可信量測裝置的描述與量子同調性認證。隨機數萃取流程則於理論層面建立，並以理想狀態的模擬數據完成驗證；隨機數生成的實驗實現留作未來工作。整體而言，此工作說明單一多體糾纏光源可在同一量子資訊架構中，同時用於多個不可信節點的操控性驗證、量測裝置描述與量子同調性認證，以及本論文於理論層面建立的隨機數生成流程。

In quantum networks, information processing relies on reliable characterization of the quantum correlations between nodes and of the measurement device at each node. However, this characterization becomes fundamentally difficult when the entanglement source and some of the measurement devices cannot be fully trusted. This difficulty is more evident in a network scenario, where a source distributes entangled states to nodes under different levels of trust and a state preparation alone is insufficient to establish which state actually reached each measurement device. Conventional measurement device tomography uses a tomographically complete set of known input states and their outcome probabilities to determine the positive operator-valued measure (POVM) elements of an uncharacterized measurement device. This thesis introduces and experimentally realizes the steering-verified untrusted measurement device tomography (SV-UMDT) framework. In this framework, an untrusted source distributes multipartite entangled states to one trusted measurement node and several untrusted measurement nodes, while a classical verifier sends basis labels and records the reported outcomes. The remotely prepared tomography input states are instead verified through genuine multipartite Einstein--Podolsky--Rosen (EPR) steering, which removes the trusted input state assumption of the conventional approach. A violation of a genuine multipartite steering witness rules out preexisting classical descriptions across all bipartitions, so that the steering verification covers the entire multipartite network and establishes that the untrusted nodes participate in a single multipartite correlation. From these verified input states and their outcome probabilities, the effective POVM elements of each untrusted measurement device are determined and applied to quantum coherence certification and, at the theoretical level, to quantum random number generation. For quantum coherence certification, the measurement operators of the untrusted devices jointly yield a lower bound on the coherence of the remotely prepared target state. For quantum random number generation, the outcomes of each untrusted device serve as its own source of randomness, while the resulting measurement parameters bound the extractable randomness of each party against classical side information. Random bits certified under this model can serve as the randomness resource required by each participant in multiparty tasks built on the same source. The protocol is experimentally demonstrated on a multiphoton entanglement platform, on which genuine multipartite steering verification, characterization of the untrusted measurement devices, and quantum coherence certification are realized. The randomness extraction workflow is developed at the theoretical level and validated on an ideal simulation, with the experimental realization of random number generation left as future work. Overall, this work shows that a single multipartite entanglement source can be used within one quantum information framework for steering verification and measurement device characterization at the untrusted nodes, for quantum coherence certification, and for the randomness generation workflow established here at the theoretical level.

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