Paper 2026/698 Original: eprint.iacr.org/2026/698 ↗

Entropy-based Fuzzy Deduplication with Perfect Resistance to Key Recovery Attack

Abstract

Deduplication for encrypted data reduces the storage costs of server while keeping the sensitive data secure. Fuzzy deduplication is developing for the multimedia data for its similarity not exact equality, hence it has better storage space saving capabilities than exact deduplication. However, the most of existing works face the security threat such as brute-force guessing attacks, key recovery attacks and so on. We conduct research on fuzzy deduplication from the fundamental layer for these security goals. In this work, the data similarity is novelty defined based on information entropy theory so that the similarity verification by cloud is without online clients assistance. Moreover, the parameter robustness verification is firstly proposed to be against the key recovery attacks and guessing attacks fundamentally. The simulation experiments show that our scheme can save approximately 87% of storage space while maintaining a tamper detection success rate of no less than 97%.