What Is a Replay Attack & How Does It Affect Blockchains?

While the cryptocurrency market has proven to be resilient and long-lasting, investing in it still comes with ample risks because of asset volatility, as well as the potential for hacking. One potential method that hackers can use to get into blockchains and essentially steal coins from other wallets involves replay attacks. These primarily take place while a hard fork is being implemented, which makes them relatively rare. This guide goes into further detail about replay attacks and how they can affect crypto platforms.

What Is a Replay Attack?

A replay attack uses malicious apps to delay or intercept data transmission that occurs over a network. This information can then be processed and repeated numerous times to effectively duplicate transactions.

Replay attacks exploit the need for the original data to be validated. This validation request is typically sent by an authorized user. Even though a replay attack is directly targeting the network, its security protocols will view a replay attack as a standard transmission of data.

During the transmission, the hacker will delay or intercept the data natively, which lets them perform the attack in a timely manner without needing to decrypt anything. Even though it's relatively easy for hackers to perform replay attacks, there are several techniques that networks can use to strengthen security and keep these attacks at bay.