Good evening, guys. A bit busy today, not much to write, just tackling this before bed. Lately, while looking at Starknet, I've been comparing its accounts to those on regular blockchains, and the potential for security upgrades seems quite interesting. On regular blockchains, signatures are basically fixed. You sign a transaction with your private key, and the network recognizes that signature format. Changing to a new signature method, such as a more secure one or one supporting biometrics, often requires a network-wide upgrade, with everyone changing their rules. @Starknet is different. Its accounts are smart contracts, with signature verification logic written in the account code. Each account has two entry points: `__validate__` checks if the signature is valid, and `__execute__` executes the actual operation. The protocol only handles basic rules like nonce and fees; the specific verification process is left to the account itself. Therefore, developers can add new signature methods to accounts, such as multi-signature, passkey, and even future post-quantum signatures, without waiting for a network-wide upgrade. The account address, balance, and history remain; only the verification logic changes. STARK proofs verify the correctness of the entire computation process, ensuring that custom logic is executed correctly within the rollup. To use a simple analogy: Accounts on a typical blockchain are like standardized door locks in a building; changing the lock requires modifying the entire building. Starknet accounts are more like your own door lock; you can change it yourself, even adding fingerprint recognition, as long as the door remains and the key matches—the neighbors don't need to move out. The computation process is notarized by STARK proofs, ensuring that after you change the lock, the house continues to operate according to the rules. Currently, it's still in its early stages, and the new signature schemes are not widely used, but in terms of direction, it does allow account security to evolve with technology, rather than being locked by the protocol. Those interested can refer to Starknet's account abstraction documentation or try creating a custom account to experience this upgradable form of security firsthand.