I'm starting to learn smart contracts in ethereum and have some questions about the concept of "Reading / Writing" state.
I know reading state doesn't cost gas.
But when we execute a read state and compute with it in the smart contract (without posting any transaction)
Who's doing the computation? is it the node that initiated the contract function?
If the computation is done locally, is it safe to use encryption algorithm in the function?
Is there any network cost? ( or the node will just compute from its chaindata? )