Cymetrics Tech Blog

In Solidity, randomness is often applied in lotteries, NFT generation, GameFi, and so on, to distribute prizes or determine the rarity and appearance of game items and other characteristics. The authenticity of the randomness used in decentralized applications directly impacts user rights. If the random outcome can be predicted or manipulated, it undermines the principle of fairness pursued by decentralized applications. Using visible information when generating random numbers in Solidity can lead to vulnerabilities related to pseudo-randomness.This article will delve into the issues of randomness in Solidity and its potential risks, providing effective solutions to help developers protect smart contracts from such vulnerabilities.

# What is Access Control ?Access control refers to "who can perform a specific action," which is crucial in the world of smart contracts. The access control of a contract can determine which roles can mint tokens, vote on proposals, freeze transfers, and execute many other essential functions. Properly implementing access control is vital to prevent unauthorized actors from performing actions.In OpenZeppelin, there are two primary ways to implement access control: Ownable and Role-Based Access Control (RBAC).Ownable grants control to the contract owner, making it suitable for simpler applications.When multiple roles or permission levels are involved, RBAC provides more granular control, enabling different roles to perform specific functions.

# What is Denial of Service ?In Solidity, Denial of Service (DoS) is a common vulnerability type that disrupts the expected execution of contract functions by exhausting resources or blocking the contract’s operation. In the blockchain world, code represents the flow of funds or the execution of internal logic. In severe cases, DoS can directly result in asset or fund immobilization, leading to losses for users or protocols.This article will introduce several common DoS scenarios:Unbounded loopIntegration/Logical errorRefund failed

Would you like to understand the pitfalls encountered in developing OpenAI?Would you like to understand how to unlock Embeddings and Retrieval-Augmented Generation to enable GPT models to generate meaningful content, even without the unique know-how of enterprises? Then hurry up and click in, and leave with a wealth of knowledge!

I'm glad that I can share some interesting insights that I've been following daily at CYBERSEC 2023 Taiwan. Red-Blue confrontation happens all the time. Red team uses new vulnerabilities and techniques to attack, while Blue team can use various mechanisms and protection to interrupt the attack. This article will introduce some useful tips and tools.

Content distribution networks (CDNs) are an important part of the modern Internet, providing fast and reliable connections and network resources to users around the world. However, while CDNs offer many benefits, they also introduce new security risks that many people may not be aware of. In this article, we'll explore the hidden dangers of CDNs and examine why CDNs may not be as secure as you think. Explore how to protect yourself and your business from these potential security risks that CDNs might introduce. This article will help you better understand the potential risks involved with CDNs and how to mitigate them.

When facing rapidly evolving customer segments and opportunities, continuously identifying sweet spots is one of the goals of a product manager, while the goal of a project manager is to ensure smooth delivery of these products, projects, and features to end users. To achieve these objectives, it is essential to establish a product development process that facilitates seamless and timely product operations, from conceptualization, design, development, to delivery. Specifically, Cymetrics breaks down the overall process into the following parts:Requirement processDesign processDevelopment process

ChatGPT is incredibly easy to use, but its development team at OpenAI has restricted many answers related to security issues in order to prevent hackers from using ChatGPT for attacks. As a result, finding correct answers without crossing the line has become a new research topic for hackers and cybersecurity experts.The purpose of this article is to share some methods for obtaining answers from ChatGPT, which can be broadly classified into two categories: those that can be exploited by attackers and those that developers need to use for protection. While the implementation in the article is based on websites, these methods are not limited to website attacks and can be useful in various other areas of cybersecurity.