System and method for improving security of smart contract on blockchain

A system for improving security of smart contract, comprising one or more processors and one or more non-transitory computer-readable memories coupled to the one or more processors and configured with instructions executable by the one or more processors to cause the system to perform operations comprising:

• obtaining a first transaction and a second transaction both invoking a smart contract without a specified order of execution and both for adding to a blockchain, wherein the first transaction is associated with an execution condition that protects execution of the first transaction from execution of the second transaction;
• executing the second transaction and updating a current state of the smart contract according at least to the execution of the second transaction;
• determining whether the updated current state of the smart contract satisfies the execution condition;
• in response to determining that the updated current state satisfies the execution condition, executing the first transaction after the execution of the second transaction, and recording the executions of the second and the first transactions into a data block for adding to the blockchain;
• and
• in response to determining that the updated current state does not satisfy the execution condition, recording the executions of second transaction into a data block for adding to the blockchain and discarding the first transaction.

A non-transitory computer-readable storage medium configured with instructions executable by one or more processors to cause the one or more processors to perform operations comprising:

• obtaining a first transaction and a second transaction both invoking a smart contract without a specified order of execution and both for adding to a blockchain, wherein the first transaction is associated with an execution condition that protects execution of the first transaction from execution of the second transaction;
• executing the second transaction and updating a current state of the smart contract according at least to the execution of the second transaction;
• determining whether the updated current state of the smart contract satisfies the execution condition;
• in response to determining that the updated current state satisfies the execution condition, executing the first transaction after the execution of the second transaction, and recording the executions of the second and the first transactions into a data block for adding to the blockchain;
• and
• in response to determining that the updated current state does not satisfy the execution condition, recording the execution of second transaction into a data block for adding to the blockchain and discarding the first transaction.