# From NFT 1.0 to NFT 2.0: A Review of the Evolution of Non-Fungible Tokens
## 3 Blockchain and Solutions for NFT
### Blockchain for NFTs
Furthermore, Cardano uses the standard CIP-721 to define an NFT metadata standard for native tokens, and mostly focuses on collectible and videogame NFTs. _EOS_ is a DPoS blockchain launched in 2017 that aims to implement a decentralised operating system [53]. It was designed to support the rapid development of decentralised applications at the industrial level by solving three of the most challenging problems of blockchain technology: transaction cost, confirmation time, and commercial scalability. EOS transactions are free, but to create them, a small upfront investment is required in the form of EOS token staking to acquire some blockchain-specific resources [54]. Concerning confirmation time, EOS can support over 4000 transactions per second, and the consensus protocol lets block creators create one block every 0.5 s. The blockchain uses C++ as the programming language for its smart contract, thus enabling scalable and high-performing decentralised applications. Among the most prominent NFT projects on the EOS blockchain, you can find AtomicMarket (a shared liquidity NFT market smart contract), Upland (the earth's metaverse mapped to the real world and accessible via web, iOS, and Android), Crypto Dynasty (an RPG&PvP dApp game), and other NFT-based games. _Tezos_[55] is a self-amending, PoS-based blockchain with a strong emphasis on formal verification. Self-amending refers to the fact that Tezos uses a protocol to validate blocks and implement the consensus that can change itself. To be able to amend itself, Tezos uses a multi-step on-chain voting system, where its users can propose changes to the protocols, and after a testing phase, a final vote decides whether to accept or reject the modifications proposed. As consensus protocols, it uses the liquid proof of stake, a variation of PoS, where users can delegate their liquidity to other nodes to increase the chance they have of creating a block. To ensure the blocks are created without cheating, block creators, also called _bakers_, have to lock some funds for 2 weeks. This fund is used as a deposit in case the block becomes irreversible and contains illegal transactions. Since the focus of the blockchain is on having a strong governance system, it only supports around 40 transactions per second, with transaction fees of about 10 cents. Tezos is written in OCaml, with some functionalities related to the cryptographic aspect of the blockchain written in C. It adopted Michelson as a domain-specific smart contract language, but also supports other languages [56]. Tezos is mostly used for artistic NFTs and collectibles. _Binance Smart Chain_ (BSC) is a general-purpose blockchain that adopts a proof-of-staked-authority (PoSA) consensus mechanism. BSC and Binance chain are two projects that run in parallel and have built-in cross-chain compatibility. BSC block creators can create a new block approximately every 3 s, supporting fewer than 100 transactions per second. BSC has support for NFTs in the form of the BEP-721 standard, which is analogous to the ERC-721 standard, which are mostly collectibles. The fees for minting an NFT are about BNB 0.005 (around USD 3 ([[https://yccharts.com/indicators/binance_smart_chain_average_transaction_fee_es](https://yccharts.com/indicators/binance_smart_chain_average_transaction_fee_es)]([https://yccharts.com/indicators/binance_smart_chain_average_transaction_fee_es](https://yccharts.com/indicators/binance_smart_chain_average_transaction_fee_es)), accessed on 23 May 2023)), which is considerably cheaper concerning Ethereum. BSC uses Solidity and Vyper languages for smart contract development to provide advanced smart contract functionality [57]. _Algorand_ is a highly efficient blockchain that is designed to overcome the major problem of the blockchain technology It adopts the pure proof-of-stake (PPoS) consensus protocol, meaning that block validators are chosen among all the token holders at random,proportionally to the amount of token held.