How can we be sure that a Pallet-account/address is unique in a chain and no one else in the chain can replicate the same address?

Question

In Ethereum, the contract address/account isn't formed trivially from a cryptographically-generated private-public key pair, but rather by using a separate method, as described here.

In Substrate, similar to this, a pallet-account is formed from inside the runtime by passing a PalletId (a unique identifier assigned to the pallet) to the into_account() function instead of passing a random seed as is done for normal account formation. For example: T::PalletId::get().into_account()

My question now is, how can we be sure that the account address won't be replicated by anyone else/ other pallets in the chain?

Answer 1

You cannot be sure that it won't be replicated. A different pallet could use the same seed (pallet id) to generate an account id and thus "impersonate" your pallet. This is not a problem, though, because the assumptions about pallets are different from smart contracts: Pallets are trusted modules included in the runtime deliberately by the people building the runtime (in contrast to smart contracts that can be created in a permissionless way). Thus it is fine to assume that the pallets included in a runtime cooperate with each other. If you need to generate an account id that cannot be easily replicated, you will want to use hashing on unpredictable/uncontrollable inputs such as the account sending an extrinsic in combination with its nonce and the current block number.