VNFTestChain: Blockchain Based Test Framework for Trusted VNF Services in 5G and B5G

This paper proposes a blockchain-based test frame-work for trusted Virtual Network Functions (VNFs) for 5G and B5G networks. In particular, the proposed framework comprises two types of blockchain viz., consortium and public and five different entities viz., developer, tester, reviewer, verifier, and badging authority. The consortium blockchain forms the first level, where initially, the digital fingerprints of the developed VNF and other relevant information are pushed by the five entities. Once a VNF successfully passes all the tests and verification, the required information of VNF life cycle are pushed from the consortium blockchain to the public blockchain, which is the second -level blockchain open to anyone. To ensure a scalable solution, we use distributed off-chain storage. Moreover, the use of smart contracts provides transparent functionality, code immutability, access control, and automation. To the best of our knowledge, this is the first test framework that proposes a combination of consortium blockchain, public blockchain, smart contracts, and distributed off-chain storage to address the security and trust issues in the existing centralized VNF life cycle.