Vulnerability challenges to Cryptocurrencies and Solutions
Since 2009 till date, more than sixteen hundred cryptocurrencies have hit the market. Their market value is more than $444.8 billion, which is continuously growing as people are investing in cryptocurrencies worldwide. Cryptocurrencies are getting more and more popular globally.
This has increased the threat of criminal attacks. Cryptocurrency does not exist physically; it is digital entirely. So, different kinds of hacking attacks can be possible. Here in this article, we'll see some vulnerabilities to cryptocurrencies and their solutions.
Cryptocurrency Vulnerabilities
Transaction Malleability
One of the vulnerabilities of cryptocurrencies is the malleability attack. The users with criminal intentions try to alter the transaction hash and pretend that amount is not received, so; the sender should resend the amount. In this way, the receiver gets an extra amount without updating the sender's balance. In this procedure, one initiates a transaction according to defined rules. During the transaction processing, the attacker changes the transaction's signature, which results in a new transaction with a new ID issued by the attacker. Both the transactions wait for approval in the network.
In this situation, if the false transaction is approved, then the original transaction is discarded. And attacker asks the sender to initiate the transaction again. In this way, the attacker receives the double amount from the sender by creating forged transactions. If the assailant makes multiple forged transactions, this can result in DoS (Denial of Service) attack. Such kinds of attacks were easy in the past, but now the situation is quite improved.
Distributed Denial of Service
DDoS or Distributed Denial of Service means unavailability of a network for the users. Cryptocurrency exchange platforms are the more likely targeted for DDoS attacks. Many techniques are used for it; pocket flooding is one of them. These attacks are highly disruptive and low-cost. That's why these are very common in cryptocurrencies. Mining pools and crypto exchange platforms are the favorite targets for DDoS.
51% Attack
Cryptocurrencies are decentralized in nature; there is no central authority or third party to control the system and decision-making. It is perfect in the Proof of Work protocol for individual miners, but it is subjected to 51% attack with the introduction of pool mining. It means if any entity or mining pool gains 51% of the total computational power employed on a blockchain, it gets the power to control the systems. In this situation, the mining pool having 51% computational power can allow its members for double-spending, can stop other pools from mine, and even can obstruct the transactions.
PoS algorithm gives an excellent solution to reduce the 51% attack. In PoS, the attacker must acquire the 51% staking, which is difficult to maintain. Without acquiring 51% of resources, one cannot get control of the system's regular activities. PoS also enhances the cost by 51% and reduces its chances.
Software bugs
According to the researchers, many software bugs are also found in many leading cryptocurrency systems. Because there are no laws and regulations to control the cryptocurrencies like banks and other financial institutes, so these are more vulnerable. The stealing points in software allow the hackers to peep into the system and play with the account balances. They can increase, transfer or withdraw the amount illegally. To remove the bugs, continuous real-time debugging is effective.
Less protected login credentials
Many of the crypto platforms are not taking tough security measures for users and employees' login credentials. Users also create weak and easy to excess passwords, which are hot cakes for hackers. In this regard, we can observe three major attacks in 2017, which were named as Bithumb hack, NiceHash hack, and YouBit hack.
Two-step verification for login can reduce the chances of hacking credentials and user funds. Additionally, a strong and difficult-to-guess password also provides security against hacking. Do not share your login credentials with anyone; keep them secret.
Selfish Mining
In cryptocurrency, there are two types of miners one is honest, and the other is selfish miners. Selfish miners are targeted to force real miners to waste their computational power and collect more rewards for themselves. one example of such of attack is they split the main blockchain into two. Only one from the two sub-blockchains is accepted. So, the miners working on the other did not get any incentive, and all their computational power goes waste. Sometimes the selfish miner works on a separate sub-chain of the blockchain secretly and releases it when other miners are about to be rewarded for their work. This type of vulnerability is not associated with all cryptocurrencies. The intelligent system has taken measures about it. In the fragmented blockchain case, the longest chain is accepted by the system to reward the honest miners. Another technic implemented by Ethereum is to hold the company's half amount and make it not minable. Both are considered beneficial for avoiding selfish mining.
Wallet
Wallets are an essential part of managing and storing cryptocurrency. Hardware, software, and paper wallet are the main categories. Hardware and software wallets can be subjected to hacking or stealing, so it looks pretty good to have a wallet backup in a paper wallet. It is also inexpensive. The software wallet is more likely to be hit by hackers, so it requires special security measures managed by the development team.
Double Spending Attack
Another vulnerability of cryptocurrency is double-spending. It means some entity of the system tries to use the same coins more than once. Whenever a transaction is started in the system, it becomes part of the transaction pool and waits for approval. During this waiting time, anyone with malicious intentions can create another transaction for the same coins. This new transaction also moves to the transaction pool, and in the confirmation process, one of these transactions is approved, and the other is declined. This happens because in cryptocurrency, a coin can be used only once. The secret of double spending is that the attacker has got more products from merchants and pays only once. To reduce the risk of double-spending, merchants who accept cryptocurrency are advised not to dispatching the orders unless six more blocks are mined after the bock containing their transaction.
Dropping Transactions
Transactions stay in the transaction pool, and the miners picked them for approval and recorded it in the block. Dropping transaction is another loss the hole in cryptocurrency mining. In this process, miners intentionally drop the transaction for speedy mining blocks and create empty blocks in the blockchain. To avoid this dropping of transactions, a fee is attached to every transaction in the system. This fee becomes an attraction for miners, and they choose it for approval. Transactions with the higher fee are more likely to be selected for confirmation.
Timejacking attack
This vulnerability is regarding the timestamps which are added to the transactions. By changing timestamp and system time, the attacker tries to create a double-spending attack. Every system takes safety measures to avoid such attacks. It is recommended that the time difference with local time should be shorter. Most systems are using the difference of 70 minutes; if it is reduced to 35 minutes, it will be an excellent barrier to avoiding time-jacking attacks.
Sybil Attack
Sometimes the user with malicious intentions creates virtual entities and tries to take over the network resources and activities. The primary purpose behind this attack is to confirm the fake transactions and getting more coins.
This issue is rightly addressed in the PoW algorithm as the physical resources cannot be multiplied virtually, which prevents the Sybil attack in the mining process. In the PoW algorithm, even dozens of fake mining entities cannot create new blocks. Another solution to this problem is the Proof of Individuality (PoI) algorithm.
Spam Transactions
Spam transactions are another vulnerability where the attacker creates spam transactions to fill up the transaction pool. This can lead to a Denial of Service attack. These flooded attacks can interrupt the normal working of the network. To reduce the number of fake transactions, a fee is associated with every transaction for the issuer. This will make this attack costly for the attacker and ultimately lead to fewer attacks of this kind.
Conclusion
Because of the digital nature and no physical exitance, there are several vulnerabilities detected in cryptocurrency systems. A continuous improvement process is going on to make the systems secure. Every system works on debugging and adding new features to secure and eliminate the risk factor. Introduction of transactions fee, PoSalgorithms, SegWit, and other steps are part of this improvement process. Nexalt, one of the forks of Lite coin, also implements a hybrid protocol which is a mix of Pow and PoS, SegWit, smart contracts, transaction fees, and many other hi-tech measures to keep the system at high performance and secure. Vulnerabilities are a fact, but it does not reduce the benefits of cryptocurrency because all the vulnerabilities will be interpreted, and systems are becoming strong and secure.