Abstract: Techniques for a privacy-based user data sharing protocol disclose a system that receives a request to consent to share user data with a subscriber device. The system identifies, based on the request, a smart contract associated with the subscriber device. The smart contract comprises one or more conditions for collecting and managing the user data. The system generates a token based on the smart contract, in which the token indicates consent by a user to share the user data with the subscriber device according to the one or more conditions. The system records the generated token to a blockchain.

Abstract: A blockchain smart contract rewriting framework system has a vulnerability detection tool, a rewriter tool, and a deployment component. The deployment component obtains a permission to upgrade the smart contract, which granted by a smart contract creator/owner. The contract rewriting framework system retrieves the smart contract from the blockchain network, and passes it to the vulnerability detection tool. The vulnerability detection tool detects a vulnerability in the smart contract, and determines a type of the vulnerability and an instruction location of the vulnerability. The rewriter tool rewrites the smart contract to include a patch for fixing the vulnerability, a patched smart contract being generated by the rewriter tool based on the type of the vulnerability and the instruction location of the vulnerability.

Abstract: A computer-implemented method for supporting smart contracts in a blockchain network includes: translating a source code of a smart contract into an abstract syntax tree model; generating a code property graph based on the abstract syntax tree model; performing an enrichment phase, wherein the code property graph is enriched with information that is obtained from the abstract syntax tree model; performing a vulnerability detection phase, wherein the code property graph is analyzed for one or more predetermined vulnerability patterns in order to detect one or more predetermined vulnerabilities; and performing a vulnerability patching phase, wherein one or more patches are applied in order to fix the one or more predetermined vulnerabilities detected in the vulnerability detection phase, wherein the one or more patches are inserted into the code property graph such that a patched code property graph is generated.

Abstract: A blockchain smart contract rewriting framework system has a vulnerability detection tool, a rewriter tool, and a deployment component. The deployment component obtains a permission to upgrade the smart contract, which granted by a smart contract creator/owner. The contract rewriting framework system retrieves the smart contract from the blockchain network, and passes it to the vulnerability detection tool. The vulnerability detection tool detects a vulnerability in the smart contract, and determines a type of the vulnerability and an instruction location of the vulnerability. The rewriter tool rewrites the smart contract to include a patch for fixing the vulnerability, a patched smart contract being generated by the rewriter tool based on the type of the vulnerability and the instruction location of the vulnerability.

Abstract: A method for securing smart contracts in a blockchain includes receiving in the blockchain a contract creation transaction having a control flow graph (CFG) and contract code for a smart contract to be created. The contract creation transaction is verified by checking a signature of a creator of the smart contract and determining that the CFG is correct based on the contract code. The verified contract creation transaction is included as a block in a distributed ledger of the blockchain.

Abstract: A method for securing smart contracts in a blockchain includes receiving in the blockchain a contract creation transaction having a control flow graph (CFG) and contract code for a smart contract to be created. The contract creation transaction is verified by checking a signature of a creator of the smart contract and determining that the CFG is correct based on the contract code. The verified contract creation transaction is included as a block in a distributed ledger of the blockchain.