Renouncing Ownership

Ethereum smart contracts are immutable – the code deployed to a given address cannot ever be changed. But users can make code upgradeable in practice by employing the “upgradeable proxy contract” design pattern.

The proxy portion of this pattern handles the redirection of incoming requests to the current “implementation” contract.

Upgrading the code consists of changing the redirection destination. This is not modifying the code – it is modifying the data.

This pattern provides no true way to renounce control. Whoever has the power to redirect the proxy can change the code forever because the proxy code itself cannot be changed.

In practice ownership is renounced by changing the owner to the null address.

The idea here is that the proxy can still be redirected by whoever has the private keys to the null address. But, as discussed in that section, assuming this is functionally “nobody” is as safe as the cryptography itself.

In the case of the Upgradeable Proxy ContractOpen Zeppelin example this looks like

setOwner(0x0000000000000000000000000000000000000000);