What is a Replay Attack?

Cyber SecurityAnti VirusSafe & Security

A replay attack is a type of network assault in which an attacker discovers and fraudulently delays or repeats a data transaction. The sender or a hostile actor intercepts the data and retransmits it, causing the data transfer to be delayed or repeated. In other terms, a replay attack is a security protocol attack that uses replays of data transmission from a different sender into the intended receiving system to deceive the participants into believing the data communication was successful. Attackers can use replay assaults to gain access to a network, obtain information that would otherwise be unavailable, or execute a duplicate transaction.

  • If the replay attack is not mitigated, networks and computers that are subjected to it will see the attack process as valid communications.

  • Replaying a message sent to a network by an attacker that was previously sent by an authorised user is an example of a replay attack.

  • Despite the fact that the communications are encrypted and the attacker does not have access to the real keys, retransmission of legitimate data or login messages might assist them in gaining adequate network access.

  • By replicating an authentication message, a replay attack can get access to resources while also confusing the destination host.

How Does a Replay Attack Work?

Take a look at this real-life assault scenario. By sending an encrypted message to the firm's financial administrator, a corporate employee requests a money transfer. This communication is intercepted by an attacker, who captures it and may now resend it. The communication is already correctly encrypted and seems valid to the financial administrator since it is an authentic message that has merely been resend.

In this case, unless the financial administrator has cause to be suspicious, he or she is likely to react to the new request. A huge quantity of money might be sent to the attacker's bank account as a retaliation.

How to Prevent a Replay Attack?

Preventing such an attack is all about using the proper encryption technology. Encrypted communications contain "keys" that, when decoded at the conclusion of the transmission, open the message.

  • It makes no difference in a replay assault whether the attacker who intercepted the initial transmission can read or interpret the key. All he or she needs to do is capture and transmit the full thing, message and key included.

  • To mitigate this risk, both the sender and the recipient should generate a fully random session key, which is a sort of code that is only valid for one transaction and cannot be used again.

  • Using timestamps on all communications is another protective strategy for this sort of attack. It stops hackers from resending communications transmitted more than a particular amount of time ago, so narrowing the window of opportunity for an attacker to listen, syphon off the message, and resent it.

  • Another way to prevent being a victim is to use a unique password for each transaction, which is only used once and then destroyed. This guarantees that even if an attacker records and resends the communication, the encryption code has expired and is no longer functional.

Updated on 23-Mar-2022 06:40:40