In traditional contracts, performance is not secured since it depends on the willingness of the parties. Smart contracts, in contrast, ensure greater level of performance which is irrevocable and automated as the unchangeable computer code ensures its performance and enforcement without any alteration by the parties. After concluding a smart contract, it does not depend on the will of the contractual parties anymore and it will be enforceable automatically without the need to any approvals from the parties. Thus, once a smart contract is concluded, it is binding for all its parties without depending on human mediatory. Even if there is a change in circumstances or the intent of the parties, it does not affect enforceability of the contract. The computer code, which represents and runs the contract, authenticates the conditions, transfers assets (the subject matter of the contract), and makes entries in the Blockchain database about such transactions. Due to this self-enforceability feature, it is claimed that smart contracts are not a subset of traditional contract law but they can substitute a system of legal enforcement. Self-sufficiency means Smart contracts do not depend on any legal agencies to exist or enforce, in contrast to classic contracts in case of incompleteness. Thus, it can be said that smart contracts provide more accurate, more efficient, cheaper and quicker enforcement of contracts.