emn178's Blog

There have been a lot of airdropped fraudulent tokens recently, this time I saw Awesome Crypto World (ACW), the method is exactly the same as the my last post Blockchain Scam - AI-A (AI Avail) Token. Checking a random transaction directly on the explorer shows that an Approve burned 0.02 BNB, but this time there is no information about the minting of Gas Token. From the Log, you can see many RankClaimed events: According to the trace of the source address of the event, the hacker used your gas t ...

StarkNet is one of the L2 solutions of ZK Rollup, which is also a popular airdrop opportunity. Here I research and organize a piece of information for your reference. As the same L2 ZK Rollup solution, the strategy is the same as the previous zkSync Airdrop Strategy. WalletUnlike zkSync, StarkNet is not an EVM-compatible, so we cannot use Metamask directly. A StarkNet-specific wallet must be downloaded. Refer to the wallet application recommended by official website: Argent X Braavos BridgeSta ...

I accidentally saw a transfer on Debank, 23000 AI-A (AI Avail), worth $1740? My intuition tells me that this is a scam. I have encountered one that cannot be transferred before. I don’t know what it is. Let’s do some research first. Go to Pancakeswap to try it, it seems that there is money to exchange. Try if I can transfer the money, the result is OK, it looks ok. Let’s take a look at Approve first, and find that the fee is very expensive (I deposited a little money later for the screenshot, wh ...

This article illustrates, through visuals and text, how to bridge and how to interact with applications. After understanding the strategy in the zkSync airdrop strategy, we can start interacting. If you want to carry out the strategy of one interaction, prepare 0.02207 ETH, and if you want to carry out the strategy of continuous multiple transactions, prepare 0.05631 ETH. zkSync 1.0 (Lite)Bridge DepositLite does not need to add the Network to Metamask, all related operations are performed on the ...

Arbitrum has been airdropped a while ago, and I heard that some people have retired by airdrop. zkSync is the next popular airdrop opportunity. Here I research and organize a piece of information for your reference. The next post zkSync Airdrop Guide Step by Step provides an step by step tutorial. Airdrop RulesBefore starting the zkSync interaction, let’s refer to the recent Arbitrum, which is also Layer 2, and the previous Optimism airdrop rules as a reference. OptimismRefer to Optimism Airdrop ...

DescriptionYou may not know that the order of declaration of variables will also affect the consumption of Gas.Since the EVM operations are all performed in units of 32 bytes, the compiler will attempt to package the variables into a 32 bytes set for access, so as to reduce access times.However, the compiler is not smart enough to automatically optimize the grouping of variables. It will group the statically-sized variables in groups of 32 bytes. For example: 12345678910111213contract MyContract ...

In the process of developing smart contract, because we want to be able to achieve matching function, we have implemented a function that can input multiple orders. As more and more features are added to our function and more and more arguments are required to ensure contractual fairness, such as miners’ fees, taker’s fee, maker’s fee and payment method of fee. We encounter to the variable too much and can not compile, and a lot of data consumed gas has also become a problem. In our matching fun ...

DescriptionYou may not think that the name of the function will also have an impact on gas consumption. In fact, in the worst case, there may be more than a thousand of gas impacts. Let’s take a look at the following code: 1234contract Test { function b() public { }} The above execution b() will consume 125 gas, then change to the following: 1234567contract Test { function a() public { } function b() public { }} This time b() becomes 147 ga ...

A smart contract development business have its costs come from the transactions of smart contracts; the gas consumption has a direct impact on the company’s costs structure. Writing contracts in an energy-saving way are essential. This article will analyze some of the factors that affect gas consumption in smart contracts. Outlining what is the most expensive instruction and uses it with caution. Gas consumption can refer to the following two tables: Table 1 Table 2 The gas used in Table 1 is ...

We had known How to Write a Library for Node.js and Browser with Mocha Unit Tests. Now, we can use some tool to calculate code coverage further. We used mocha before, so we choose jscoverage because it can support mocha. Please done your unit tests before start. Installation1npm install jscoverage --save-dev Ignored FilesIf we don’t want to include some files, we can add the list to .covignore in the root of project. And write like this: 12/tests/node_modules/ Eg. we don’t want to include test ...