When talking about "freezing" stablecoins, it refers to the ability to block or freeze users' funds on certain blockchains, typically centralized ones or those with control mechanisms allowing issuers (or intermediaries) to intervene directly with the funds.
1. Visa (2-3 seconds): Visa has integrated blockchain technology into its operations to enable payments and transactions with stablecoins, using networks like Solana and Ethereum for fast transactions. The reason Visa can process payments in 2-3 seconds is due to its highly optimized structure and ability to select fast blockchains. However, Visa is a centralized entity, and depending on its agreements with stablecoin issuers, it could support freezing funds if required by those issuers.
2. Solana (2-3 seconds): Solana is a very fast and scalable blockchain. Rapid transactions in 2-3 seconds are possible thanks to its architecture, which uses Proof of History (PoH) and optimizes the network's throughput. While Solana is decentralized, stablecoins like USDC or USDT issued on its network can be controlled or "frozen" by the issuer, such as Tether or Circle, who have the power to block addresses and freeze funds at the contract level.
3. Ethereum (12 seconds): Ethereum has slower average block times compared to Solana, which explains the 12 seconds. On Ethereum as well, centralized stablecoins like USDC or USDT can be "frozen" by issuers because the keys to these coins' smart contracts are held by centralized entities that can intervene in the funds for specific reasons (e.g., legal or security issues).
4. Cardano (self-custody): Cardano is built on a transaction model that supports self-custody. This means that if you hold the private keys to your assets on Cardano, you are the only one in control of them. Stablecoins on Cardano that follow this principle cannot be centrally "frozen" because Cardano does not have a centralized control mechanism over them, and the network's architectu dere is designed to be decentralized. Therefore, if a stablecoin on Cardano adheres to decentralization principles and is not controlled by the issuer, then it cannot be "frozen" by anyone except the holder of the keys
The concept of "freezing" thus depends more on the centralization of the stablecoin (and the issuer) than on the blockchain itself.
