What is Replay Attack?

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A replay attack is the type of malicious attack which is initiated by the hacker on a secure network to intercept a communication. Once the interception takes place, the messages are sent to the wrong node so that the conversation can be moulded as per hackers’ needs.

These kinds of attacks are carried out by the attacker who is intercepting the data and re-transmitting them at their own time and use. This is kind of a low level for the Man-in-the-middle attack where the attacker uses the security protocols which uses the replay of the messages and fools the participants thereby gaining trust and access.

These types of attacks can be prevented by understanding the encryption methodology. Usually, when cryptography is used, the message is encrypted and transmitted. On the receiver side, the message is opened using the decryption approach.

When the message is intercepted by the hacker, they need to direct it using the same set of keys used to encrypt/decrypt the message. This helps in preventing the actual users from knowing if the message has been intercepted.

To avoid such attacks, the sender and receiver are asked to establish a session key randomly. This session key represents a code type that will be valid for single interaction between sender and receiver. This code can't be established again.

Apart from this, timestamps can also be used. Timestamp comes with a time limit and hackers won't be able to send a message with an expired timestamp.

One can also make use of passwords every time a session is established or data is sent across. The password is to be used only once. This is also called the OTP scheme or onetime password. The password remains valid for a short amount of time.

Hence cryptography systems can prevent these attacks by tagging the message after encryption with either password or session ID or both. The solution is not dependent on any other element which makes it easy to use. It also makes it less vulnerable.

Prevention of Replay Attacks

The ways to prevent replay attacks are as follows −

  • The authentication session considers the transaction takes place in time. The password is tied with a timestamp approximately and according to that modifies it.

  • First assign a large session token to a session and the sender sends a password modified by session token value. This session token can be used only once.

  • The information authentication is sent may be a hash of the password added to the session token and again hashed.

Updated on 24-Mar-2022 08:06:08