A replay attack occurs when an attacker intercepts a data transmission between two parties and then fraudulently re-transmits the data to impersonate one of the parties, thus gaining unauthorized access or causing malicious actions.
In the context of a blockchain, a replay attack can be prevented through the implementation of measures such as using unique transaction IDs, including timestamps in transactions, and incorporating cryptographic techniques like digital signatures to verify the authenticity of transactions. By using these methods, blockchain participants can ensure that each transaction is unique and cannot be maliciously replayed by an attacker.
