Experimental Evaluation of Cryptographic Models for Blockchain Security and Privacy in Smart Environments

Abstract

Blockchain technology into the healthcare sector, logistics, finance, and massive IoT system, this technology is making its way into it. With the issue of privacy becoming much more critical than before in the adoption phases. Even though blockchains provide integrity and resistant storage against tampering, numerous implementations still expose behavioural evidence, time-based data, besides other forms of metadata, which may be compromised by inference attacks. These breaches become more apparent when there is an exchange or near real-time processing of sensitive information. This paper will analyze the performance of three widely discussed privacy-saving methods Zero-Knowledge Proofs (ZKP), Homomorphic Encryption (HE), not to mention Differential Privacy (DP) in a practical blockchain architecture and not in isolation. A testbed made of Hyperledger Fabric and Ethereum instances privately owned was constructed to enable each of the methods to be tested under the same conditions. The experiments made trade-offs of transaction suspensions, added computational load, and exposure to metadata-based attacks.The results demonstrate that ZKP-based settings store observable metadata substantially and restricted the amount that an adversary would deduce regarding transaction patterns. HE was a good implementation in areas where safe computation was needed but with significant latency overhead. The least significant communication impact was on DP, which was, however, to be carefully tuned in terms of its privacy parameters to prevent the decline in protection. We further conducted simulated attacks to research into the reaction of each approach to pressure and detail how validation can be extended in the future with the aid of open datasets through the MIMIC-III, OpenAQ, and TII cybersecurity logs. On the whole, the findings provide useful insights to teams, who want to embed cryptographic privacy tools in production-scale blockchain systems in particular in those industries where confidentiality and data protection cannot be jeopardized.