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The term smart contract was coined by cryptologist Nick Szabo TICHU
DE proposed that blockchain smart contracts have the ability to access off-chain data by integrating decentralized oracles. The open source smart contract introduced to you today means that the internal code of the system is completely open, and users can change or add corresponding functions according to their needs. Non-open source means that the copyright belongs to the developer, and users do not know the source code content and cannot modify the source code. Generally speaking, those who are open source belong to the active side, and those who are not open source belong to the passive side. Many investors may still not know what open source smart contracts mean? Let the editor of the currency circle explain smart contract open source in a simple way.

 What does smart contract open source mean?

Smart contract open source means that the internal code of the system is completely open, and users can change or add corresponding functions according to their needs. Smart contracts allow pre-established rules to be executed openly, fairly and securely, without being maliciously tampered with. The concept of "smart contracts" was proposed as early as 1994. However, due to the lack of a credible execution environment and system at the time, smart contracts were not applied to actual industries.

When Bitcoin was born in 2009, Bitcoin transactions had simple executable scripts and simple logic could be executed. People are gradually realizing that the underlying technology of blockchain can naturally provide a trusted execution environment for smart contracts. However, Bitcoin's support for smart contracts only remains at the level of simple scripts. It does not have Turing completeness and cannot implement more complex logic. Therefore, Bitcoin's script only opens up the development of applications based on smart contracts.

With the emergence of Ethereum, smart contracts can be applied from simple experiments to implementation. For a mature blockchain technology system, smart contracts are a very important technical feature and one of the main reasons why blockchain can be called a disruptive technology.

 Execution process of smart contract

(1) User A initiates a signature transaction, and the target account is B. B is a smart contract account and stores the smart contract code. Assuming that the transaction is broadcast and packaged at this time, the node needs to store the transaction on the blockchain and play back and calculate the transaction.

(2) The client (defined as implemented in C code) calls Chrome
V8 engine loads the contract code into the engine for execution. During execution, if a built-in interface is encountered, a callback function will be generated to call the client code. At this time, the two-way interactive function is realized.

(3) During the execution of the contract, new transactions may occur. For example, account B of the contract transfers money to account C through the interface within the contract. If account C is just an ordinary account, then only ordinary transfers are required; if account C is a contract account, a new contract will be triggered again, forming a recursive call. The recursion depth of calling the contract is 3 levels. If it exceeds 3 levels, an error will occur and the entire transaction will be rolled back. This is considered and designed due to the complexity of contract implementation and the security of the underlying blockchain.

The content above is the currency circle editor’s popular explanation of what open source smart contracts mean. After the smart contract is executed, all nodes involved are updated to the new state. Smart contract technology has been given a new lease of life through applications such as non-fungible tokens, DeFi systems, record investments and market caps. However, many systems running on smart contracts are being compromised due to poor implementation of smart contracts, inadequate security mechanisms and exploited vulnerabilities throughout the software development life cycle (SDLC). Smart contract security begins before the first line of code is written – during the planning, design and development phases, and finally protecting smart contracts from cyberattacks and potential vulnerabilities.