Key Rotation

Key rotation is replacing the key that controls an account with a new one, so that a key which may have been exposed stops being useful. Whether it is possible at all depends on the account type, and that is the whole practical lesson. A plain key-controlled account cannot be rotated: the address is derived from the key, so the only equivalent is generating a new wallet and moving every asset to it, paying fees and leaving the old address permanently associated in public history. A smart contract account separates ownership from the funds, so the owner key can be swapped while the address and its balances stay put. Multisig and threshold arrangements go further and let one signer be replaced without disturbing the others, which is what makes them workable for a group whose members change. Rotation is a response to suspected exposure and to the passage of time, not a substitute for finding out how a key was exposed, and on a plain account it should be treated as an evacuation rather than a maintenance task.