OpenZeppelin AccessControl vs Ownable: Granular vs Simple Ownership

Dynamic role management: Roles can be granted and revoked programmatically, enabling complex governance flows. Essential for upgradable contracts (like UUPS or Transparent proxies) where the admin role might be a TimelockController.

Single owner model: One address has all administrative rights. Results in ~20-30% lower gas costs for ownership checks and transfers compared to AccessControl. Ideal for simple, founder-controlled NFTs or tokens.

Reduced attack surface: No complex role hierarchy to audit or manage. The onlyOwner modifier is straightforward. Best for rapid prototyping or contracts where a single EOA or multisig is the unequivocal authority.

Role-based security model: Enables fine-grained access control (e.g., MINTER_ROLE, PAUSER_ROLE, UPGRADER_ROLE). This is critical for multi-sig governance (e.g., Compound, Aave) and protocols where separation of duties is a security requirement.

Dynamic role assignment: Admins can grant/revoke roles to multiple addresses without changing core contract logic. This matters for DAO-managed protocols where council members or committees need specific, updatable permissions.

Single-owner model: One owner address controls all privileged functions. This results in ~20-30% lower gas costs for deployment and function calls vs. a basic AccessControl setup. Ideal for simple dApps and quick prototypes.

Minimal complexity: Fewer state variables and functions to audit. The onlyOwner modifier is straightforward, reducing risk of role management bugs seen in improperly implemented AccessControl. Best for solo developers or small teams with a clear admin.

Increased complexity and cost: Requires managing role hashes, admin roles, and emits more events. Not cost-effective for simple NFT drops or token contracts where a single admin suffices.

Centralized risk: Compromise of the single owner private key leads to total protocol control loss. Unsuitable for Treasury management or high-value DeFi pools where multi-sig or role-based revocation is mandatory.

Single-owner model: One owner address controls all privileged functions. This reduces contract size and deployment gas by ~15-20% versus a basic AccessControl setup. Ideal for rapid prototyping or simple contracts where a multisig or EOA manages all upgrades and settings.

Linear ownership history: The transferOwnership pattern provides a straightforward, on-chain record of control changes. Easier for auditors and users to verify than complex role assignments. Fits protocols where governance is handled off-chain (e.g., Snapshot) and on-chain execution is centralized.

Role-Based Access Control (RBAC): Define multiple roles (e.g., MINTER_ROLE, UPGRADER_ROLE) and assign them to multiple addresses or contracts. This is the industry standard for production DeFi (used by Aave, Uniswap) as it minimizes single points of failure and enables least-privilege security.

Decoupled administration: Separates the role admin (who can grant/revoke) from the role bearer. Enables secure protocol composability where external contracts (like a timelock or DAO) manage permissions. Essential for DAO-governed protocols or those using upgrade proxies (UUPS/Transparent).

Centralized risk: A compromised owner key can drain the entire contract. Not suitable for TVL-heavy protocols (>$1M) without a robust multisig, which then negates the simplicity benefit. Lacks internal mechanisms for multi-sig or DAO integration.

Increased development and audit surface: Managing role hashes, admin roles, and revocation logic adds complexity. Can increase initial audit costs by 10-30% and requires more thorough testing. Overkill for simple, non-upgradeable contracts with a small team.