SignatureReplay

Signing messages off-chain and having a contract that requires that signature before executing a function is a useful technique.

NFT-Marketplace-with-Zero-Gasfee

NFTMarketplace with Gasless Minting 1. An NFT marketplace is a digital platform for buying and selling NFTs. These platforms allow people to store and display their NFTs plus sell them to others for cryptocurrency or money. Some NFT marketplaces also allow users to mint their NFTs on the platform itself. 2. The platform allows you to list NFTs without paying any gas fees. This is achieved by pushing the blockchain transaction forward to when someone purchases the token. But, when listing an NFT on OpenSea, the seller's MetaMask – or any other wallet – will trigger

Smart-contract_vulnerabilities

Smart contract vulnerabilities refer to weaknesses or flaws in the design, implementation, or execution of smart contracts that can be exploited by attackers. These vulnerabilities can lead to unintended consequences, financial losses, or security breaches within the blockchain ecosystem