Yogesh Kulkarni

Decentralized Finance for Coders [Free Video Course]

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This course will show you the ins and outs of decentralized finance (DeFi). Each step links to a more detailed article/tutorial, so you can dive deeper into the rabbit hole. Let’s get started! Step 1: Getting Started with DeFi What is DeFi? Decentralized Finance, also referred to as “DeFi,” enables customers to access financial services … Read more

MakerDAO 101 for Coders – How DeFi Lending and Borrowing Works

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This is in continuation of the first part of our DeFi series. 💡 Abstract: In this article, we will see how decentralized lending and borrowing work. It starts with comparing centralized finance (CeFi) with decentralized finance (DeFi) lending and borrowing. You’ll then learn about the most important Ethereum based DeFi decentralized apps (dapps) for lending … Read more

Polygon for Developers – A Simple Guide with Video

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What are Polygon and MATIC all about and why is another blockchain needed? You will find answers to these questions in this article. The article starts with problems plaguing Ethereum, workable solutions to the problem, and then dives into more details of the Polygon network, its history, tokenomics, and an overview of the Polygon SDK. … Read more

Smart Contract Replay Attack in Solidity

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This is part 8 and a continuation of the Smart Contract Security Series. Ownership Exploit Private Variable Exploit Reentrancy Attack tx.origin Phishing Attack Denial of Service Attack Storage Collision Attack Randomness Attack Replay Attack This post provides insights into the replay attack in blockchains. As per the wiki, a replay attack is a valid data … Read more

Smart Contract Randomness or ReplicatedLogic Attack

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This is part 7 and a continuation of the Smart Contract Security Series. Ownership Exploit Private Variable Exploit Reentrancy Attack tx.origin Phishing Attack Denial of Service Attack Storage Collision Attack Randomness Attack Replay Attack In this tutorial, the randomness attack or also called replicated logic attack is analyzed. The problem in Solidity contracts is finding … Read more

DelegateCall or Storage Collision Attack on Smart Contracts

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The post is part 6 and continues our Smart Contract Security Series: Ownership Exploit Private Variable Exploit Reentrancy Attack tx.origin Phishing Attack Denial of Service Attack Storage Collision Attack Randomness Attack Replay Attack The DelegateCall attack or storage collision is expounded in this post. Before you can grasp this exploit, you must first understand how … Read more

Ethereum Smart Contract Fuzz-Testing with Echidna

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What is Fuzzing?                 Fuzz testing (or fuzzing) is an automated software testing method with the goal to find vulnerabilities, security issues, and defects of the application. The idea is to inject invalid, malformed, or unexpected inputs into the application using a fuzzing tool and observing how the system reacts to those inputs (e.g., exceptions, leakage … Read more

Denial of Service (DoS) Attack on Smart Contracts

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This post is part 5 of our Smart Contract Security Series: Ownership Exploit Private Variable Exploit Reentrancy Attack tx.origin Phishing Attack Denial of Service Attack Storage Collision Attack Randomness Attack Replay Attack The post discusses the Denial of Service or alias the DoS attack. The Denial of Service (hence referred to as DoS) restricts legitimate … Read more

tx.origin Phishing Attack — Smart Contract Security

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This post is part 4 of our Smart Contract Security Series: Ownership Exploit Private Variable Exploit Reentrancy Attack tx.origin Phishing Attack Denial of Service Attack Storage Collision Attack Randomness Attack Replay Attack In this post, we discuss phishing attacks due to tx.origin. In the regular phishing of a website, phishing begins with a phony email … Read more