Security Enhancements for Data-Driven Systems: A Blockchain-Based Trustworthy Data Sharing Scheme

Algorithm 1

The process of the proposed scheme.

	Require: DO: the encrypted data , the contract’s program code , the secret key shares ; DC: the request .
	Ensure: the data .
	procedure DATA RELEASE:
	DO sends and to CS;
	CS publishes to blockchain;
	DO checks
	if the in the blockchain is correct, then
	DO sends the secret key shares to the kTEE .
	procedure Data retrieval:
	DC revokes the smart contract with input ;
	CS loads and into the sTEE;
	sTEE performs remote attestation with kTEEs
	if sTEE environment and loaded data are correct, then
	The kTEE transmits to the sTEE;
	Step 2.4: CS executes the smart contract in the internal
	sTEE to obtain a reencryption key;
	CS computes the reencrypted ciphertext
	outside the sTEE;
	CS sends the reencrypted data to the
	blockchain;
	DC obtains and decrypts it to obtain .