What does replay mean in the context of cybersecurity?

In the context of cybersecurity, replay refers to the process of capturing and retransmitting valid data transmissions. This is typically done by an attacker who intercepts these messages during their transmission between two parties. By replaying the messages, the attacker can gain unauthorized access or carry out actions using the intercepted information. This method exploits the fact that the original message may not have any special protections against this kind of duplication, allowing the attacker to impersonate the original sender or interact with the receiving party as if they were legitimate.

Replay attacks can pose significant risks, especially in systems where authentication is not properly managed, and they require robust security measures, such as timestamps, nonces (number used once), or session tokens to ensure that each transmission is unique and cannot be reused maliciously. The other options relate to different aspects of data handling and transfer but do not capture the specific threat posed by replay attacks.