Smart contracts operating on the existing blockchains often become subject to attacks aimed at stealing or manipulating data on the blockchain ledger. Some of the most common threats include the reentrancy attack (calling back the affected contract before its execution is carried out to drain funds from the system), unauthorized access attempts (forging login data to get access to user funds or data), and DoS attacks (disruption of the platform’s normal operations via excessive resource consumption). Smart contracts also sustain timestamp dependency attacks and malicious code insertion efforts by hackers.