Have you ever bitten into a sandwich only to realize that it wasn’t what you were expecting? Sometimes, things aren’t always what they seem – and this holds true in the world of smart contracts as well.
Let's understand "Sandwich Attack"
Smart contracts are becoming increasingly popular in the world of blockchain technology. They enable automated transactions to be executed without the need for intermediaries. Making them a powerful tool for streamlining processes and reducing costs. However, smart contracts can also be vulnerable to attacks. One such attack is the Sandwich Attack. Which involves a bad actor manipulating the market by placing multiple transactions in a short period of time. This can cause losses for other traders who are caught in between the transactions.
For example, let’s say a trader wants to buy 100 DAI using ETH. They place a limit order on a decentralized exchange for 100 DAI, with the trade to be executed at a price of 0.01 ETH/DAI. However, before the trade is executed, a bad actor places two orders on the exchange – one to buy DAI with a large amount of ETH, and another to sell DAI for a large amount of ETH. These orders are placed at prices slightly above and below the original limit order. Creating a price sandwich around the original trade.
As a result, when the trader’s order is executed, they end up paying more ETH for the DAI than they intended, as the price of DAI has been artificially inflated by the bad actor’s trades. This type of attack is known as the Sandwich Attack.
So how can developers prevent the Sandwich Attack in their smart contracts?
Here are some steps to take:
Use Time-Weighted Average Price (TWAP) Oracles
TWAP oracles calculate the average price of an asset over a period of time. Which can help prevent sudden price changes and make it more difficult for attackers to manipulate the market. By using a TWAP oracle in the smart contract, developers can help ensure that prices are fair and transparent.
Implement Security Measures
Developers can also implement other security measures. Such as setting transaction limits or using permissioned access control to limit who can interact with the smart contract. This can help prevent attackers from gaining control of the smart contract and executing malicious transactions.
Thoroughly Test and Audit the Code
It’s important to thoroughly test the code and conduct a security audit before deploying the smart contract to the blockchain. This can help identify potential vulnerabilities and ensure that the code is secure and free from exploitable flaws.
At Novvr, we specialize in smart contract auditing and can help identify and mitigate risks like the Sandwich Attack. Our team of experts can review the code to ensure that it is secure and provide recommendations for improving its security.
By taking a proactive approach to security, developers can help prevent the Sandwich Attack and other types of attacks on their smart contracts. With the right tools and expertise, smart contracts can be a powerful tool for driving innovation and efficiency in a variety of industries.