DynaEDI+: Reliable and Decentralized Integrity Verification for Dynamic Edge Data

In an edge computing environment, data can be cached on edge servers to enable fast data services for users. These edge data are subject to corruption and must be verified to ensure their integrity. Meanwhile, they are also subject to partial content changes over time. Existing edge data integrity (EDI) schemes are designed to verify edge data as a whole. They fail to accommodate partially identical edge data and consequently suffer from low verification accuracy in many real-world applications. In the meantime, their reliability is subject to compromises caused by edge servers' Byzantine behaviors. This paper presents DynaEDI+, a novel decentralized EDI scheme capable of verifying the integrity of partially identical edge data. It introduces pairing trees, a new tree-based data digest structure, to enable subtree-based content comparison, allowing precise identification of version-matched data blocks. To reduce communication overhead, DynaEDI+ transmits only root nodes instead of entire trees for verification. It also implements a series of security mechanisms to safeguard the verification process against evasion attacks, replay attacks, and theft attacks from Byzantine edge servers. Theoretical analysis proves that DynaEDI+ can effectively defend against potential threats from Byzantine edge servers. Experimental results demonstrate that DynaEDI+ achieves high accuracy in edge environments with partially identical data and Byzantine edge servers, while reducing communication overhead by an order of magnitude compared to benchmark schemes.