What is the meaning of the Delegate Call? A delegate call is a calling mechanism in smart contracts that allow the caller contract to send a message to a target contract, but the execution of the related code is done in the context of the caller, which essentially means that if contract A makes a delegatecall to another…

What is Gas in Smart Contracts? Gas is a measurable unit that is used to measure the computational power in Ethereum smart contracts. It refers to the cost necessary to perform a transaction on the network. Whenever a user interacts with a smart contract or performs a transaction, miners need to process this input in the…

The Need for Pseudo-Random Number Generators Random number generators are used extensively in all kinds of applications such as gambling, deciding winners in games, getting random seeds for test data, etc. However, generating random numbers on Ethereum is a challenging task due to its deterministic nature and the fact that each time a function is called in…

In the previous blog, we talked about the selfdestruct function and how it can be abused by malicious attackers to exploit the contracts and extract all the funds. If you’ve not read the previous post, we recommend a quick read before you proceed with this one. …

What is selfdestruct()in solidity? Contracts can be deleted from the blockchain by calling selfdestruct. It is used to destroy a contract and transfer the remaining funds to the address specified while calling the function. Why selfdestruct() is used? There are many use cases for selfdestruct function like: In case of…

Before starting CredShields, I was exploring popular blockchains and understanding their features and functionalities. During that time, I found a bug in Avalanchego that could alow anyone to crash their live testnet (They were not on mainnet at that time). The exploring: The best way to understand and test a blockchain…

What is pragma in Solidity? A pragma is usually the first line of code in any Solidity file. This directive specifies the compiler version to be used for the compilation of the smart contract code written in Solidity. How does Solidity pragma work? Solidity Pragma is always local to a source…

Understanding access control in Smart Contract Access controls define the restrictions around privileges and roles of users in an application. Access control in smart contracts can be related to governance and critical logic like minting tokens, voting on proposals, withdrawing funds, pausing and upgrading the contracts, changing ownership, etc. OpenZeppelin…

A few months ago, during an audit of one of CredShields’ clients, we uncovered a race condition in Tendermint’s Starport that allowed any user to bypass the faucet withdrawal limits. This blog post discusses the postmortem of the race condition bug. What is tendermint? Tendermint, now known as Ignite, is…