Smart Contract Replay Attack in Solidity

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

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

Transposition Algorithm in Python (Expert Guide)

What is a Transposition Algorithm? A substitution algorithm, such as previously mentioned Caesar’s algorithm, works by substituting each symbol of the plaintext message with another symbol, according to a predetermined offset defined by a key. In contrast, a transposition algorithm shifts, or changes the positions of its symbols by following a specific, predetermined key. Since … Read more

Ethereum Smart Contract Fuzz-Testing with Echidna

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

Security Engineer — Income and Opportunity

Before we learn about the money, let’s get this question out of the way: What Does a Security Engineer Do? A security engineer is a “white-hat hacker”, i.e., an IT professional who analyzes computer systems and computer networks to ensure they are running securely. This involves proactive analysis and understanding of possible security threats and … Read more

Caesar Cipher in Python

Caesar Cipher is a simple encryption and obfuscation method. It’s a straightforward substitution cipher that replaces each plain text character with the obfuscated character obtained by shifting the plain text character a fixed number of positions in the alphabet. What is Cryptography? Before we introduce our first cryptographic algorithm, Caesar’s cipher, let’s first introduce cryptography … Read more

Denial of Service (DoS) Attack on Smart Contracts

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

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

Reentrancy Attack – Hacking Smart Contracts [Solidity]

You can check out the code for this article on our GitHub. Preamble This post is part 3 in continuation of our Smart Contract Security Series. This post is part 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 … Read more