What is an Eclipse Attack? A Beginner’s Guide

If you have been keeping tabs on decentralization, then you already know just how significant the whole thing has become; there is definitely a future out there for decentralization. Financial enterprises are doing their best to adopt cryptocurrencies in whatever way or form they can. The most appealing aspect of cryptocurrencies is the overall security they enjoy; there is a saying that cryptocurrencies, because of decentralization, are the most secure and unreachable entities out there. Because the whole thing relies on the prospect of blockchain technology, the very fact that it remains immutable provides a certain kind of security edge to the whole scenario. 

Also, a hacking attempt at a definitive cryptocurrency or that of decentralization would be met with fierce tackle down because a consensus needs to be reached for any and every setting of blockchain technology to be altered in any potential way. This means that all the validators that are taking part in validating the transactions must reach a consensus and agree that the transaction has actually transpired for it to become an active part of the blockchain. This only proves the mettle of blockchain technology and its resilience towards hacking or any kind of cyber threat stomping on its very definition of security.

But that doesn’t mean that blockchain technology is completely resilient to any and all sort of hacking; there are still some pretty intensive hackers out there who, when provided with a suitable chance or opportunity, would grab it and call arms over the blockchain network. One such attack, which we will be talking about shortly, is known as an Eclipse attack. It is the fatal cyber security breach that a blockchain network can sustain. To be able to move further with the prospect of how this attack works and what are the various significant aspects of it towards the very definition of security within the blockchain technology, you must at first understand what this attack is.

What is an Eclipse Attack?

Blockchain technology is the accumulation of multiple user nodes that are working in harmony towards the authentication of transactions taking place on the network. The information is shared between these nodes in a peer-to-peer manner which makes up for a decentralized networking system with no user having more superiority over the other. There are blockchains that are private and those that are public. 

Public blockchains have no filter whatsoever when it comes to people joining the network, whereas private blockchains are literally more private, and they just don’t allow any person or random user to connect with the network, there is a proper screening process there, and the user who wants to connect must have a security key or a private key which he would enter for the sake of connecting with the network. This is how private and public blockchain systems work. During the initiation of the attack, a hacker is going to isolate a potential user working as a validator onto the blockchain network. 

The very purpose of the attacker here is to procure targeted users’ view of the peer-to-peer network so that they can prepare for the onset of more intimate attacks or to initiate a general disruption within the network. There is a grave similarity between the Eclipse attack and Sybil attacks, but the end goal of these remains different. The possible similarity between the two is that the network is consistently and rapidly gets overcompensated with compromised peers. 

The difference, on the other hand, is that during the onset of the attack, only a single node gets compromised, and the attack then rolls over from there, taking over the whole network in the form of an eclipse. Whereas in the Sybil Attack, the complete network is compromised in a single go. The only thing that an attacker requires to be able to pull off a successful Eclipse attack is to construct as many compromised nodes within the network as possible. 

All of these nodes will work as a hoax, whereas other users believe these to be legitimate. At the end of the cycle of verifying each transaction, whichever node finds the answer to the complex mathematical problem has to share the result with the rest of the nodes. Not knowing that most of the nodes are illegitimate and a hoax, they will share the information with them as well, thus providing access to the attackers on every possible level.

Even if there are safeguards in place to stop the Sybil attack, as it is more dangerous than an Eclipse attack, attackers would be overriding the maintenance systems for the sake of mounting an Eclipse attack; hence those safeguards will not be able to prevent the Eclipse attacks in the long run. There was earlier a paper drafted in 2015 regarding attacks on Bitcoin peer-to-peer network, and the authors submitted the results regarding the launch of an Eclipse attack as well as the possible countermeasures that could be taken to prevent it from spiraling out of control.

During the progression of an Eclipse attack, the attacker is going to try to redirect all the intended network participants’ connections both in and out from potentially secure nodes to the hoax nodes that are prepared and set up by the attacker. This sophisticated act will seal off the target from the usual network. When a new user joins the network, they won’t be joining the legitimate one but the one developed by the attacker. Since the new user gets disconnected trying to access the original blockchain ledger, the isolated node which the user has joined could be further tricked by the culprit. 

It could lead to the confirmation of illegitimate transactions where the user might believe that they have transacted some amount from their wallet and received some, whereas, in the literal sense, they have done nothing. There could also be disruptions to the mining activities associated with an eclipse attack. The present structure of the underlying blockchain network will help in determining how this blockchain effect can take place and to what extent.

How Does Eclipse Attack Work?

To be able to completely understand how the eclipse attacked, you need to bring forward the idea of a blockchain network. It is a beadlike continuation of nodes that are interconnected with each other in a peer-to-peer fashion. All these nodes correspond to particular computing elements that are controlled by users who are, in an accumulative sense, the very blockchain of a dedicated cryptocurrency. Attackers who want to run an eclipse attack are artistically going to use either a phantom network or a botnet to be able to bring the security of a particular node of the network and to close it off. 

The single node that gets attacked could be because of the fact that its security is minimal or next to nothing, and when the attack is successful, that particular node gets sealed off from the normal network activity. This means that any user that will connect with the network and end up at the compromised node would think that they are at the right node, whereas they will be completely at the mercy of the attacker. 

There are bandwidth limitations that don’t allow all these nodes present within a blockchain network to connect with each other and pass information in a consistent manner. Therefore during skipping of the connection from one node to another, a particular node or section of blockchain could get seriously compromised. 

The attacker is going to utilize the available nodes to which the user connection bounces off for the sake of compromising the user network. When gaining access to the user network, the attacker could then launch its own network from the host node and will be then target the target nodes with multiple Internet Protocol locations. This will allow the potential target to connect with the network developed when it kind of reconnects with the original network. 

Neither the user nor the blockchain system would know that they have a compromised node on board and would continue to act as if nothing unusual has happened. All that is left then for the attacker is to wait until the target reconnects with compromised nodes and if there is some kind of delay with the user connecting with the network. If there is, then the attacker would launch a DDoS attack casting the user out of the network completely; hence the target will be compelled to connect once again with the network. 

The most disturbing element of an eclipse attack is that as soon as a target node is taken over by the malicious actor, the same attacker goes on to feed false data into it. For the most part of the act, the victim remains completely clueless that the specific point has actually been compromised. This is what makes this attack so sophisticated and sneaky. Following are a few consequences that the eclipse attack would bring onto the crypto projects and their blockchain systems;

Miner Power Disruptions

There is a proper check and balance in place when it comes to the addition of blocks in a blockchain environment. This means that even after an eclipse attack has transpired, those blocks that have no legitimate data could just be discarded as easily from the blockchain as it goes. But during the initiation of the eclipse attack, some of the blocks that are legitimate and should be made part of the blockchain don’t get included because the attacker is trying to mask the fact that the block was mined from an illegitimate user/node.  

This might mislead the user into giving away their processing power along with time to process and or mine the blocks that have been compromised already. This way, the attacker will enhance their own hash rate. Attackers know that a victim is going to be separated original blockchain network, and thus winning this opportunity, they can launch attacks on other miners of the network and even launch a fifty-one percent attack on the network that would end up with deadly consequences ahead.

Double Spend Attack

Since a portion of the blockchain has been compromised and an attacker is in charge of it, any victim who connects with this discarded portion of the blockchain network could be misled and misdirected to believe into anything. It is a perfect illusion that the attacker can control in any potential way they want to. This means that the victim could be misdirected into accepting the transaction with either an illegitimate input or the input from an already confirmed and recorded transaction over the official blockchain network. 

These are known as double-spend attacks, in which the victim is confused into accepting a transaction that has already been accepted by someone else and has already been validated within the network. When the eclipse attack is over, the corrupt data is still going to be there, and it is going to cause a lot of problems not only for the network but also for the legitimate users involved in financial activity across that time period when the network was being compromised.

Eclipse Attack and its Effects

When a culprit simply attacks a user on the blockchain network, they might have an ulterior motive behind this. Usually, attackers who engage with the eclipse attack have something else on their mind, they want to entrench a more complicated series of consistent attacks, and the eclipse attack is only going to work as a gateway for that to happen.

Zero-Confirmation Double Spends

The potential user of the blockchain network might be over the risk of a double-spend attack if they confirm a transaction that has no confirmation and or record of ever being happening or validated on the blockchain network. According to the principle, the transaction was already recorded and broadcasted to the other miners and validators, but the sender still can’t initiate a brand new transaction and use these funds to be spent anywhere else. The double-spending might continue to become a problem for the user until the transaction in question has been subjected to the blockchain and then committed onto the original blockchain network. 

Sometimes new transactions with a possible higher fee could also get included within the blockchain environment to invalidate the transactions that have happened earlier. The riskiest element of this whole trade is that few enterprises might continue to accept these transactions with no earlier confirmation whatsoever, and that is a problem in the long run.

N-Confirmation Double Spends

The N-confirmation double spends are kind of similar to the 0-confirmation-transactions, but for an attacker to completely and consistently pull this off would initiate much more complicated preparation. Many businesses that are associated with digital finance are in the habit of holding new payments or subjecting the recent ones as invalid, especially if there are specific transactions that are yet to come; this makes them vulnerable to these kinds of attacks. Attackers in this specific scenario will be able to target not only the merchants but miners as well. 

They can open an outstanding order with the merchant and broadcast this transaction to the miners that were affected during the attack. This will lead to the transaction being confirmed and then eventually added into the blockchain environment. But the chain on which the subjection of this information is taking place is not legit and has already been eclipsed.

Both parties would presume that the transaction is valid and has come through, but in reality, it hasn’t. The attacker would then be able to provide this specific block version to the merchant where the merchant will think that the payment has already been released, and he, in turn, would release the goods and or services.

An eclipse node within the network might lead to the production of multiple other nodes, and these will also begin to operate because the victim remains unaware of anything unusual or of the fact that they were initially cut out from the original network. Miners would continue mining new blocks as if nothing has happened and when the syncing with other peers takes place, these blocks are added by the victim who has been cut off from the original network. 

The large-scale eclipse attacks that are executed on multiple miners at the same time might eventually be able to initiate a fifty-one percent attack. The most elementary way of stopping eclipse attacks is to put forward some kind of screening process where all the inbound, as well as outbound connections could be scanned to make sure that these are indeed safe. 

Another thing that could be practiced is to only make connections to the outbound sources that are available to the particular nodes that the blockchain entity could trust and develop a whitelist of those peers within the network. This is the most elementary way of stopping the eclipse attack and or continuation of this drama any further.