Analysis and Improvement of Blockchain-Based Multilevel Privacy-Preserving Location Sharing Scheme for Telecare Medical Information Systems

Table 2

Comparison of previous schemes.

Schemes	Zyskind et al.’s [7]	Amoretti et al.’s [8]	Ji et al.’s [9]	Our scheme
Decentralization	√	√	√	√
Untamperability	√	√	√	√
Confidentiality	√			√
Multilevel protection				√
Retrievability	—	—	√	√
Verifiability	—	√	√	√