블록체인과 그룹 키 관리를 활용한 안전한 차량용 무선 펌웨어 업데이트

다국어 초록 (Multilingual Abstract)

Conventional over-the-air （OTA） firmware update systems perform per-vehicle encryption and rely on a central server for both encrypted firmware delivery and key distribution. This architecture is vulnerable to network condition variations, leading to scalability limitations and single points of failure. Consequently, it poses considerable challenges to security, scalability, and reliability in large-scale vehicular environments. To address these issues, this study adopts an Access control vector broadcast group key management （ACV-BGKM） based group key management scheme to distribute keys and disseminate firmware in a distributed environment using blockchain and the InterPlanetary File System （IPFS）. This approach enables efficient and stable firmware distribution for a large number of vehicles. Furthermore, to overcome the computational complexity of ACV-BGKM, we introduce a novel matrix partitioning technique that enables efficient computation and management of firmware encryption keys, even in large scale vehicular networks. In addition, a role-based access control （RBAC） mechanism is applied to smart contracts to ensure that only authorized users can register firmware and related information on the blockchain, thereby preventing malicious data registration. Unlike existing blockchain based OTA approaches that primarily use blockchain for data integrity verification, the proposed framework leverages blockchain for active participation in firmware distribution, realizing a fully decentralized update architecture. This constitutes a key distinguishing feature of this work. Through simulation based evaluations, we demonstrate that the proposed approach serves as an effective solution for secure and efficient OTA firmware updates in large-scale vehicular networks.

목차 (Table of Contents)

• Ⅰ. 서론 1
• Ⅱ. 배경지식 및 관련 연구 6
• 2.1 블록체인 6
• 2.2 스마트 컨트랙트 7
• 2.3 IPFS 7
• 2.4 RBAC 8
• 2.5 ACV-BGKM 9
• 2.6 관련 연구 12
• Ⅲ. 블록체인과 IPFS 기반 OTA 펌웨어 업데이트 시스템 15
• 3.1 펌웨어 암호화와 IPFS 업로드 16
• 3.2 블록체인 기반 펌웨어 정보 등록 19
• 3.3 블록체인 조회와 펌웨어 제공 요청 23
• 3.4 펌웨어 복호와 업데이트 24
• Ⅳ. 그룹 키 생성과 행렬 분할 25
• 4.1 ACV 생성을 위한 그룹 분할 및 관리와 행렬 분할 26
• 4.2 그룹 및 행렬 분할 예시 29
• Ⅴ. 구현 및 성능 평가 33
• 5.1 구현 33
• 5.2 성능 평가 환경 37
• 5.3 DDoS 공격에 대한 업데이트 성공률 40
• 5.4 대규모 정상 업데이트 요청 처리율 41
• 5.5 구현 43
• 5.6 암호화 연산 비용 45
• 5.7 행렬 연산 확장성 47
• Ⅵ. 결론 50
• 참고문헌 52
• Abstract 59