隨著數位轉型的加速，跨國醫療憑證的驗證已成為全球醫療產業 的關鍵需求。歐洲區塊鏈服務基礎設施（EBSI）雖提供了基於去中心 化識別碼（DID）與可驗證憑證（VC）的信任鏈模型，但其現行架構 高度依賴即時的區塊鏈查詢以驗證信任關係，導致系統無法在離線環 境下運作，且維護中心化白名單的成本過高。為此，本論文提出兩項機制。第一，提出身分基礎階層式數位錢包與金鑰產生架構，將主管機關至使用者的授權關係嵌入信任鏈，無須即時查詢鏈上名單即可驗證憑證來源，支援離線驗證並提升擴充性。第二，提出具金鑰絕緣之多方簽密稽核機制，確保醫療服務與資料授權經醫生、病人雙方同意，結合 IPFS 鏈下保存與區塊鏈鏈上索引，雙方皆能授權稽核者存取，以維護資料機密、完整與多方不可否認性。本研究可協助境外醫療機構於網路受限時驗證憑證，並於跨國醫療爭議、保險審查或合規稽核時，提供由病患控制揭露範圍、具醫病共同責任歸屬的可信證據。

With the acceleration of digital transformation, the verification of cross-border medical credentials has become a critical requirement in the global healthcare industry. Although the European Blockchain Services Infrastructure (EBSI) provides a trust chain model based on Decentralized Identifiers (DIDs) and Verifiable Credentials (VCs), its current architecture relies heavily on real-time blockchain queries to verify trust relationships. This dependency prevents the system from operating in offline environments and incurs excessive costs for maintaining centralized whitelists. To address these challenges, this thesis proposes two mechanisms. First, an identity-based hierarchical digital wallet and key generation architecture is proposed. By embedding the authorization relationships—from competent authorities down to end-users—into the trust chain, this architecture allows verifiers to authenticate credential sources without real-time queries to on-chain registries, thereby supporting offline verification and enhancing scalability. Second, a key-insulated multi-party signcryption auditing mechanism is proposed to ensure that medical services and data authorizations are mutually agreed upon by both the doctor and the patient. By integrating off-chain storage via IPFS with on-chain indexing via blockchain, both parties can authorize designated auditors to access the records, which maintains data confidentiality, integrity, and multi-party non-repudiation.
This research can assist overseas medical institutions in verifying credentials under network constraints. Furthermore, in the event of cross-border medical disputes, insurance reviews, or compliance audits, it provides trusted evidence featuring joint doctor-patient accountability and patient-controlled selective disclosure.

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