A Multiuser Ciphertext Search Scheme Based on Blockchain and SGX

Table 2

The comparison of functionality and security with the existing schemes.

Schemes	Encryption algorithm	Pregenerated indexes	Authorized access	Blockchain-based	Multiuser scenario	Execution environment/leakage risk
Wang and Fan [29]	Symmetric	√	×	×	×	Cloud server/high
Chen et al. [30]	Public key	√	×	√	×	Smart contract/high
Liu et al. [10]	Symmetric	√	×	√	√	Smart contract/high
Fu et al. [15]	Homomorphic	√	×	×	√	Cloud server/high
Our scheme	Symmetric	×	√	√	√	SGX/low