Ethereum: Invariant Tests Not Fuzzing with Foundry

As a developer working on Ethereum-based projects, you’re likely familiar with the importance of testing your code thoroughly. However, in this article, we’ll explore why invariant tests are not fuzzing using the Foundry suite.

What are invariant tests?

Invariant tests are unit tests that ensure individual components of a system behave as expected at specific points in time. They’re essential for catching regressions and ensuring the correctness of your code. In Ethereum, invariant tests typically involve interacting with contracts or modules to verify their behavior under different conditions.

Why aren’t invariant tests fuzzing?

Fuzz testing is a technique used to simulate input values to test the robustness of a system against various attack vectors. It involves generating random inputs and verifying that the output matches expected results. Invariant tests are inherently deterministic, meaning they follow a specific path based on their implementation.

When you run invariant tests in Foundry, it’s likely that the test suite is using a combination of these deterministic paths to generate input values. Since_foundry uses the following techniques to generate random inputs:

• Random number generation: The test suite can use external libraries or internal state to generate pseudo-random numbers.

• Simulation: Foundry can simulate certain conditions to mimic real-world scenarios, such as transactions or user interactions.

While these techniques are generally effective for testing, they don’t produce true randomness like a truly random number generator would. As a result, the test suite is unable to simulate a wide range of attack vectors that could be used in fuzz testing.

When does fuzz testing fail?

Fuzz testing may fail when:

• Random number generation: The generated numbers are not suitable for simulating different attack vectors.

• Simulation: Foundry’s simulation techniques may not cover all possible scenarios, leading to incomplete or misleading results.

• State-based inputs

  : The test suite relies on the internal state of the system being correctly updated after each iteration. If this is not the case, the test will fail.

Conclusion

Invariant tests are an essential part of any testing strategy, but they’re not suitable for fuzz testing due to their deterministic nature. Foundry provides a range of tools and techniques to generate random inputs, but it’s crucial to understand when these methods may not be sufficient.

To improve the effectiveness of invariant tests in your foundry test suite, consider the following strategies:

• Use external libraries: Leverage third-party libraries for generating pseudo-random numbers or simulating specific conditions.

• Increase simulation complexity: Foundry can simulate more scenarios by using techniques like parameterized testing or random walk simulations.

• Update internal state management: Ensure that the system’s internal state is correctly updated after each iteration to prevent issues with fuzz testing.

By acknowledging these limitations and taking steps to address them, you’ll be able to create a more robust test suite for your Ethereum-based projects using Foundry.

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Ethereum Wallets for Android: Support for Cold Storage and Armory-Like Functionality

As a user of Ethereum, you’re likely aware of the importance of secure wallet storage. With the rise of decentralized finance (DeFi) and non-fungible tokens (NFTs), online wallets have become increasingly popular. However, they often lack the features you need to securely store your Ethereum funds offline. In this article, we’ll explore Android-based wallets that support cold storage and Armory-like functionality.

What is Cold Storage?

Cold storage refers to the process of storing cryptocurrency offline, using hardware or software solutions to prevent unauthorized access. This approach provides an added layer of security against hacking or theft. Most online wallets require you to connect them to your computer or mobile device to transfer funds, but this can be vulnerable if not done securely.

Armory-Like Functionality: A Key Feature

Armory is a popular Android app that allows users to create and manage multiple Ethereum wallets with Armory-like functionality. The app uses advanced security features to enable secure offline storage of Ethereum funds. With Armory, you can:

• Create multiple wallet addresses

• Set up automatic backup and restore procedures

• Use QR code scanning or USB connections for offline storage

Android-Based Wallets that Support Cold Storage

Several Android-based wallets support cold storage and Armory-like functionality. Here are some examples:

• MyEtherWallet (MEW): MEW is a popular Ethereum wallet with built-in cold storage capabilities using Hardware Wallets like Ledger or Trezor. You can store your Ethereum funds offline on an external USB device or use the MEW app to connect it to your tablet or netbook.

• Etherscan Wallet

  

  : Etherscan Wallet uses a secure cold storage solution called “Trezor” for storing Ethereum funds offline. The wallet app allows you to scan QR codes and transfer funds directly to your offline device.

• Coldcard Wallet

  : Coldcard Wallet is another popular option that supports cold storage using external hardware devices like the Ledger or Trezor. You can use their app to connect it to your tablet or netbook, and then store Ethereum funds offline.

• PhishCoin: PhishCoin is a cryptocurrency wallet that uses a secure cold storage solution called “Ledger” for storing Ethereum funds offline.

Tips for Using Android-Based Wallets with Cold Storage

To get the most out of Android-based wallets with cold storage, follow these tips:

• Make sure your device has a compatible hardware wallet or external USB device installed.

• Set up automatic backup and restore procedures to ensure your wallet data is safe in case of device loss or damage.

• Use QR code scanning or USB connections to transfer funds offline when connected to an external device.

Conclusion

Ethereum wallets have come a long way in terms of security features, but cold storage remains a crucial aspect of protecting your funds. By exploring Android-based wallets that support cold storage and Armory-like functionality, you can significantly enhance the security of your Ethereum wallet. Remember to choose a wallet with built-in or compatible hardware solutions for the best offline storage experience.

Recommended Wallets:

• MyEtherWallet (MEW)

• Etherscan Wallet

• Coldcard Wallet

• PhishCoin

Remember: Always research and evaluate wallet features and security before making a purchase.

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Metamask: Mumbai – Transaction Underpriced Nightmare

As a developer of Web3 applications, I’ve encountered numerous issues with transaction fees on platforms like Ethereum. One platform that has been consistently plagued by underpriced transactions is Metamask for Mumbai. In this article, we’ll explore the problem and provide solutions to mitigate the issue.

The Problem

Metamask, being a popular wallet for Web3 applications, allows users to interact with various blockchain networks, including Ethereum. However, in my experience, sending transactions from Mumbai (or any other location) often results in underpriced fees. This may seem minor, but it can add up quickly when dealing with high-value transactions.

For instance, if you’re sending a 1ETH transaction from Mumbai to an Ethereum network, the fee might be around 0.0005 ETH or even lower. While this isn’t excessively expensive, it’s still a significant amount of money that could have been earned by other users on other networks with more competitive fees.

The Issue

There are several reasons why transactions in Mumbai might incur underpriced fees:

• Limited scalability: Mumbai is one of the few Indian cities with limited internet connectivity and high-bandwidth requirements, which can lead to slower transaction processing times.

• High network congestion: The Mumbai blockchain has experienced significant congestion in recent months, causing delays and increased fees for transactions.

• Inefficient gas price settings: Some users may not be aware of the optimal gas price settings for their specific use cases, leading to higher-than-expected fees.

The Solution

To mitigate these issues and reduce underpriced transaction fees on Metamask for Mumbai:

• Use the ” Mumbai” network: This will help you avoid local congestion and ensure faster transaction processing times.

• Optimize gas price settings: Use a reliable gas price aggregator like GasPriceAPI or getGasPrice to find the best gas prices for your specific use case.

• Increase your balance: Having more Ether in your Metamask wallet can help reduce fees, as you’ll have less of a “fee pool” to drain.

• Consider using a different wallet: If possible, switch to a wallet with faster transaction processing times and lower fees, such as a centralized wallet or a wallet on another blockchain.

Conclusion

While Metamask for Mumbai can be a convenient option, the underpriced transaction fees associated with it may not be ideal for every user. By understanding the causes of these issues and implementing solutions like using the Mumbai network, optimizing gas price settings, and increasing your balance, you can enjoy more competitive transaction fees on this platform.

Additional Tips

• Make sure to regularly check the Ethereum blockchain’s “gas prices” section to stay up-to-date with the latest prices.

• Consider using a different wallet or switching to a centralized wallet for better performance and lower fees.

• Keep in mind that some gas price adjustments may occur due to changes in network congestion, so it’s essential to be aware of these fluctuations.

By being mindful of these factors and taking steps to mitigate underpriced transaction fees, you can enjoy a more seamless Web3 experience on Metamask for Mumbai.

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How ​​AI is shaping the future of economic models on the blockchain

The advent of blockchain technology has revolutionized the way we think about economic models. By enabling secure, transparent, and decentralized data storage, blockchain has opened up new opportunities for businesses to innovate and compete more effectively. Artificial intelligence (AI) is also playing a key role in shaping the future of these economic models.

The Rise of Blockchain-Based Economic Models

Blockchain technology, popularized by cryptocurrencies such as Bitcoin and Ethereum, has enabled the creation of decentralized applications (dApps) that can operate independently of central authorities. These dApps are designed to be transparent, secure, and fair, making them attractive to businesses looking to disrupt traditional economic models.

One such example is the development of “smart contracts,” self-executing agreements with the terms of the agreement written directly into lines of code. Smart contracts have the potential to automate complex transactions, eliminate intermediaries, and reduce costs for financial market participants.

AI-Powered Economic Models

As blockchain-based economic models continue to gain traction, AI is playing a key role in shaping their future. Here are some ways AI is transforming economic models:

• Predictive Analytics: AI-powered predictive analytics can help businesses predict market trends, identify potential risks and opportunities, and make more informed investment decisions.

• Risk Management: AI-powered risk management systems can analyze vast amounts of data to identify potential security threats and alert administrators to take proactive measures to mitigate them.

• Optimization: AI algorithms can optimize economic models by identifying the most cost-effective solutions for businesses, reducing waste, and increasing efficiency.

• Personalized Pricing

  

  : AI-powered pricing strategies can be tailored to individual customers based on their preferences, behavior, and financial history.

Case Study: The Impact of AI on Supply Chain Management

One notable example of how AI is shaping economic models in blockchain is in the area of ​​supply chain management. Companies like Walmart and Maersk are using AI-driven systems to optimize their logistics operations and reduce costs.

For example, Walmart’s “Just-in-Time” inventory management system uses AI-powered algorithms to predict demand and adjust inventory levels in real time. This allows businesses to maintain a smooth flow of goods while minimizing waste and reducing costs.

The Future of Economic Models

As the blockchain ecosystem continues to mature, we can expect to see even more innovative applications of AI in economic models. Some potential areas of focus include:

• Decentralized Finance (DeFi): DeFi platforms powered by AI will enable new types of lending and borrowing transactions, allowing for greater flexibility and speed.

• Supply Chain Optimization: AI-powered systems will continue to improve supply chains by reducing waste, increasing efficiency, and improving customer satisfaction.

• Cryptocurrency-Based Economic Models: As cryptocurrency prices fluctuate, AI-powered economic models will need to adapt to changing market conditions.

Conclusion

The intersection of blockchain and AI is revolutionizing the way we think about economic models. By harnessing the power of AI, businesses can create more efficient, secure, and transparent systems that drive innovation and growth. As this ecosystem continues to evolve, one thing is certain: the future of economic models on blockchain will be shaped by the intersection of these two technologies.

Sources:

• “Blockchain-Based Economic Models” by J.K.

TRANSACTION

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“Scaling, Scaling, Scaling: How Stark and Fantom Are Revolutionizing Cryptocurrency with Layer 2 Technology”

As the cryptocurrency world continues to grow and evolve, two innovative projects, Stark (STRK) and Fantom (FTM), are making great strides in leveraging layer-2 scaling solutions. In this article, we will dive into their exciting applications of these technologies and how they are set to revolutionize the cryptocurrency ecosystem.

Layer 2 Scaling: The Need for Speed

Traditional blockchain networks like Ethereum have been criticized for their high transaction fees and slow transaction times. This has led to a growing demand for faster, cheaper, and more scalable solutions. Layer 2 scaling technologies like Stark and Fantom are designed to solve these problems by moving heavy loads from the main chain to secondary chains or sidechains.

Stark (STRK): The Fast Leader

Stark, developed by the Stark Network team, is a pioneering project that is pushing the boundaries of layer 2 scalability. Its innovative approach uses a combination of sharding and tokenization to reduce transaction times and fees. By leveraging advanced algorithms, Stark aims to provide a seamless user experience for both users and developers.

One of the key features that sets Stark apart is its “layer 1” architecture, which enables faster and more efficient transactions on the Ethereum network. This allows users to interact with smart contracts and decentralized applications without sacrificing performance or security. Thanks to its cutting-edge technology, Stark has already gained considerable popularity among cryptocurrency enthusiasts.

Fantom (FTM): The DeFi Pioneer

Fantom, developed by the team at Fantom Labs, is another leader in the layer-2 scaling space. Its focus on “DeFi” (Decentralized Finance) allows for seamless integration with existing DeFi protocols and applications. Using a combination of tokenomics, staking, and liquidity provision, Fantom allows users to participate in various DeFi activities without the need for traditional exchanges or wallets.

Fantom’s innovative approach has attracted significant attention from institutions and individual investors. Its focus on scalability, security, and usability has cemented its position as one of the leading layer-2 scaling solutions on the market.

Compare and Contrast

While Stark and Fantom face similar challenges in their respective projects, they differ significantly in terms of approach, architecture, and use cases. Stark’s focus on sharding and tokenization sets it apart from Fantom’s DeFi-focused approach.

Here’s a side-by-side comparison of the two:

• Sharding: Stark uses a combination of sharding and tokenization to reduce transaction times and fees.

• Tokenomics: Fantom uses staking, liquidity provision, and tokenomics to enable seamless participation in DeFi activities.

• Use Cases: Stark is designed primarily for transaction processing, while Fantom caters to the broader DeFi ecosystem.

Conclusion

As we continue to explore the exciting world of cryptocurrency, it’s clear that layer 2 scaling solutions like Stark (STRK) and Fantom (FTM) are poised to disrupt the cryptocurrency landscape. With their innovative approaches, cutting-edge technology, and focus on scalability, usability, and security, these projects have the potential to disrupt the status quo and create new opportunities for users, developers, and institutions.

Whether you are a seasoned crypto enthusiast or a novice just starting out, it is crucial to stay informed about these exciting developments and how they will shape the future of cryptocurrency.

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Correct Usage of Bitcoin: Separating Fact from Fiction

When talking about cryptocurrency, the terms “Bitcoin” and “bitcoin” are often used interchangeably. However, there is a subtle difference between using “Bitcoin” with a capital B and “bitcoin.” In this article, we will explore when to use each term, highlighting any potential confusion.

Misunderstanding: Using “Bitcoin” as “bit coin”

A common misconception is that all instances of “bitcoin” refer to cryptocurrency. However, this is not entirely correct. Although both terms are used to describe the same asset, they have different meanings.

When talking about the currency itself, “bitcoin” (with a capital B) refers to a digital or virtual token designed by an individual known as Satoshi Nakamoto in 2009. The term has become synonymous with both digital currencies and cryptocurrencies. When discussing digital payments, investments, or exchanges, it is common to use both terms: e.g., “I want to buy bitcoin.”

On the other hand, when we talk about Bitcoin (with a lowercase b), we are referring to the underlying technology that enables peer-to-peer transactions without intermediaries. This specifically refers to the protocol, software, and hardware required for Bitcoin transactions. In this context, it is more accurate to use “bitcoin” with a lowercase b.

Correct Usage: Uppercase B or Lowercase b

To avoid confusion:

• Use
  uppercase B

  when referring to the digital currency itself.

• Use
  lowercase b

  

  when referring to the underlying technology, protocol, software, and hardware that enable Bitcoin transactions.

Bottom Line

While “Bitcoin” and “bitcoin” are often used interchangeably, it is important to understand the subtle difference. By using a capital B for the currency and a lowercase b for its underlying technology, you will avoid potential confusion and ensure a more accurate discussion of cryptocurrency-related topics.

Be informed, be clear!

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Ethereum: Why JSON-RPC over SSL is “Heavily Deprecated”

The Ethereum community has long been vocal about the importance of using secure communication protocols to interact with the Ethereum network. Recently, a question was raised on the Ethereum Wiki as to whether JSON-RPC over SSL (SSL Secure) is still considered “heavily deprecated.” In this article, we will explore why JSON-RPC over SSL is no longer recommended, and explore an alternative solution.

A Brief History of JSON-RPC

JSON-RPC (JavaScript Object Notation Remote Procedure Call) has been a widely used protocol for interacting with Ethereum decentralized applications (dApps) since its inception. It allows dApps to invoke operations on other nodes on the network using standard HTTP methods such as GET, POST, PUT, and DELETE. However, JSON-RPC uses TCP connections over HTTP, which is not suitable for secure communication.

SSL Problem

SSL/TLS (Secure Sockets Layer/Transport Layer Security) is a cryptographic protocol that provides end-to-end encryption on the Internet, ensuring that data transmitted between clients and servers remains confidential and secure. However, JSON-RPC uses TCP connections over HTTP, which is not encrypted. This makes it vulnerable to eavesdropping, tampering, and man-in-the-middle attacks.

“Strongestly Deprecated” Mark

In 2015, the Ethereum community officially deprecated the use of SSL/TLS for JSON-RPC connections due to the inherent security risks associated with standard HTTP encryption. The reasoning was simple: JSON-RPC over SSL offers no additional security benefits over standard HTTP encryption.

Why is JSON-RPC over SSL still “strongly discouraged”?

While it is true that JSON-RPC over SSL is no longer recommended, there are a few reasons why this label persists:

• Legacy systems: Many legacy dApps have already integrated JSON-RPC into their infrastructure, and upgrading to an alternative solution may be expensive or impractical.

• Third-party libraries: Some third-party libraries for Ethereum development still support JSON-RPC over SSL, making it a viable option for those who cannot or do not want to switch to HTTPS.

• Security considerations: While using SSL/TLS is not recommended, there are some security scenarios where plain HTTP encryption is acceptable. For example, if all connections are encrypted with the same key (e.g. using a shared secret), using SSL/TLS may be sufficient.

Alternative Solution: JSON-RPC over TLS

Ethereum developers have implemented an alternative solution for JSON-RPC over TCP, known as “eth-rpc” or “rpc-tls”. This protocol uses Transport Layer Security (TLS) encryption to protect all TCP connections between nodes on the Ethereum network.

Here is an example of how you can implement TLS in your dApp:

import { createServer } from 'http';
const server = createServer((req, res) => {
// JSON-RPC over TLS
const encryptedData = encrypt(JSON.stringify(req.body));
res.writeHead(200, {
'Content-Type': 'application/json; charset=utf-8',
});
res.write(encryptedData);
res.end();
});
server.listen(80); // Listen for TLS connections on port 80

In this example, we create an HTTP server that uses the eth-rpc protocol to secure all TCP connections. Note that this is a simplified example and you should refer to the Ethereum documentation for more information on configuring the eth-rpc server.

Conclusion

While JSON-RPC over SSL is no longer “strongly deprecated”, it is important to understand the reasons behind this designation and consider alternative solutions, such as TLS encryption.

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Here is a comprehensive article on “Crypto”, “API”, “Trading” and “Isolated Margin”, with “Token” as one of the key concepts:

Title: “The Power of Tokens in Crypto API Trading: A Comprehensive Guide”

Introduction

In recent years, the world of cryptocurrency trading has seen significant growth and innovation. At the heart of this trend is the use of APIs (Application Programming Interfaces) to facilitate trading between various exchanges, brokers and marketplaces. One of the main benefits of using tokens in cryptocurrency API trading is their ability to provide a secure, transparent and efficient way to execute transactions. In this article, we will explore how tokens can be used in cryptocurrency API trading, including isolated margin strategies.

What are Tokens?

Tokens are digital assets that represent a claim on a specific asset or commodity. They have gained significant popularity in the cryptocurrency industry due to their ability to provide a new level of security and transparency in financial transactions. In the context of cryptocurrency API trading, tokens can be used as collateral for positions, representing a percentage of the value of an asset.

Isolated Margin Trading

A popular strategy for traders using tokens is isolated margin trading. This involves using a token to secure a position on an exchange or market, allowing traders to borrow assets from other exchanges without being exposed to the risk of margin calls.

Here are some key benefits of isolated margin trading:

• Enhanced Security: By using a token as collateral, traders can reduce their exposure to margin calls and credit risks.

• Flexibility: Isolated margin trades allow traders to access multiple markets with different leverage options, increasing their overall flexibility.

• Improved Liquidity: Token-backed positions can provide better market access and liquidity for traders.

API Trading Platforms

In recent years, several API trading platforms have emerged, allowing users to trade cryptocurrencies using tokens. Some popular examples include:

• Binance API

  

  : Binance’s API allows users to execute trades with up to 100x leverage.

• Huobi API: Huobi’s API provides access to a wide range of markets and leverages of up to 50x.

• Kraken API: Kraken’s API allows traders to execute trades with up to 20x leverage.

Tokenized Leveraged Trading

An innovative approach to token-based trading is the use of leveraged trading tokens. These tokens represent a specific share of an asset, allowing traders to access multiple markets and leverage positions. Some popular examples include:

• FLOCO: FLOCO is a leveraged trading token that allows users to trade Bitcoin with 1:100 leverage.

• LEO

  : LEO is another leveraged trading token that offers 10x leverage across various cryptocurrency markets.

Conclusion

The use of tokens in cryptocurrency API trading has revolutionized the way traders access and execute trades. By leveraging isolated margin strategies, using API trading platforms, and employing leveraged trading tokens, traders can increase their security, flexibility, and overall performance. As the cryptocurrency world continues to evolve, it is essential for traders to stay informed about the latest developments in this space.

Disclaimer: This article does not provide investment advice or recommendations. Always conduct thorough research before making any trades and consider consulting with a financial advisor before making any decisions.

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Ethereum and Binance API Issues: A Solution for Creating Limit Orders

As a cryptocurrency enthusiast and developer, you are not alone in facing the frustration of encountering the LOT_SIZE error when creating limit orders on the Binance API. In this article, we will delve into the reasons behind this issue and provide a solution to resolve it.

The Problem: LOT_SIZE Error

The LOT_SIZE (1013) error is an internal error that occurs during the execution of a limit order on the Binance API. The exact cause of this error can be difficult to determine, but common culprits include:

• Incorrect or missing required parameters

• Inadequate or missing market data

• Insufficient balance in your account

The Problem: Minimum Amount

One possible reason for the LOT_SIZE error is an issue with the minimum amount parameter. When setting the minimum amount of a limit order, you may be exceeding the available margin in your account.

To solve this problem, let’s look at some Python code examples and explore possible solutions.

Sample Code: Creating Limit Orders with Binance API

import requests









Replace with your Binance API credentials and endpoint URL
api_url = "

Define query parameters for creating limit orders
query_params = {
"symbol": "ETHUSD", 
Specify the asset pair
"side": "limit", 
Specify whether it is a buy or sell order
"type": "order", 
Order type (in this case, limit)
"direction": "buy", 
Direction of the trade (buy/sell)
"quantity": 0.1, 
Order amount (in decimal format, e.g. 100)
"timeInForce": "good Till Cancelled" 
Time in force for the order
}

Configure Authentication and headers
headers = {
"Content-Type": "application/json",
"X-MBX-APIKEY": "YOUR_API_KEY"
}

Execute the query
response = requests.post(api_url, json=query_params, headers=headers)

Check if the response contains any error messages
if "error" in response.json():
print("Error:", response.json()["error"]["message"])
else:

Handle the successful API response
order_id = response.json()["data"]["orderID"]
print(f"Limit order created: {order_id}")

Resolving the LOT_SIZE error

Looking at your code, you can see that setting the min_quantity parameter to 0.1 is probably incorrect. causing the error. You can try increasing this value to ensure sufficient margin in your account.

Also, make sure that:

• Your account balance has sufficient funds for the transaction.

• The lotSize API call (in this case, LOT_SIZE) returns a successful response with no errors.

Additional Tips and Troubleshooting

To troubleshoot the issue, consider checking the following:

• Verify that your Binance API credentials are correct and up to date.

• Make sure you are using the correct API endpoint URL for limit order creation (

• Check the response JSON for any other errors or warnings.

If none of these steps resolve the issue, please provide more details about your setup and environment, including your Binance API credentials, account information, and code snippets. We’d be happy to help!

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