What is a Replay Attack? How Can Blockchains Be Protected Against These Attacks?
Security is not easy as much as you expected. There are new and unique types of attacks comes into action by hackers every new day. Replay Attack is one of them.
What is Replay Attack?
Replay attack is a type of network attack in which an attacker first detects a data transmission on the network then repeats or delayed that data transmission. This attack is also known as playback attack.
In simple words, a replay attack is performed to bypass security protocol by fooling the honest participants using duplicated data or by repeating the original data on the network. It helps the attackers to gain access to the network.
How a Reply Attack works?
Lets Anna wants to prove his identity to Monty. Monty requests his password as proof of identity, which Anna dutifully provides ( like a hash function) meanwhile, Attacker is looking on the conversation and keeps the password (or the hash). After the connection is over, Attacker ( as Anna) connects to Monty, when he asked for a proof of identity, Attacker sends Anna’s password (or hash) read from the last session which is accepted by Monty and thus granting access to the Attacker.
How Can Blockchains Be Protected Against These Attacks?
Blockchain ledger can be attacked when there are some changes occur through chain like hardfork. Hardfork splits the chain into two in which one is original chain and second one is new updated code chain.
Whenever these hardfork occured, the Blockchain ledger can be go through replay attack by attackers.
Mostly there are some some security protocols are included to protect the blockchain from these replay attacks during hardfork.
Blockchain can be protected from replay attacks by using two types of security measure. These are known as strong replay protection and opt-in replay protection.
In strong Replay protection , a special rule is defined on new forked chain by which it checks that the any transaction happened on it will not be valid on the original chain, as well as the other way around. This type of protection was used in first Bitcoin hardfork, BitcoinCash.
Opt-in replay protection is used when there is some network upgrade occurred in the
The main difference between these two protections is strong replay protection is executed automatically whenever hardfork occurred and opt-in replay is executed manually by users to protect chain from replay attacks.
The most commonly used technique to protect yourself from a replay attack is to block the transfers of coins until blockchain creates certain blocks.
Also read : What is Dusting Attack? Is your BTC secure?
