http://invest2yqojcel4yszjieewcfysgmp3ozjl25ssye3gtzxrnjrqhr4yd.onion/bitcoin-etf/index25.html
Indeed, even the basic public key ownership mechanism is implemented via a script: the script takes an elliptic curve signature as input, verifies it against the transaction and the address that owns the UTXO, and returns 1 if the verification is successful and 0 otherwise. Other, more complicated, scripts exist for various additional use cases. For example, one can construct a script that requires signatures from two out of a given three private keys to validate ("multisig"), a setup...