Access control patterns in Blockchain / Solidity - Cheat Sheet & Quick Revision

Recall & Review

beginner

What is Access Control in blockchain?

Access Control in blockchain means deciding who can do what actions on the blockchain, like reading data or making changes. It helps keep the system safe by allowing only trusted users to perform certain tasks.

beginner

Explain the Role-Based Access Control (RBAC) pattern.

RBAC gives permissions to users based on their roles. For example, an 'admin' role can add or remove users, while a 'viewer' role can only see data. This makes managing permissions easier and clearer.

intermediate

What is the Attribute-Based Access Control (ABAC) pattern?

ABAC controls access by checking user attributes like age, location, or membership status. It uses rules that combine these attributes to decide if someone can do an action.

intermediate

Describe the Capability-Based Access Control pattern.

This pattern gives users special tokens or 'capabilities' that prove they have permission to do certain actions. If a user has the right token, they can perform the action without checking roles or attributes every time.

beginner

Why is Access Control important in smart contracts?

Smart contracts run automatically and control valuable assets. Access control ensures only authorized users can trigger sensitive functions, preventing theft or mistakes.

Which access control pattern assigns permissions based on user roles?

A Role-Based Access Control (RBAC)

B Attribute-Based Access Control (ABAC)

C Capability-Based Access Control

D Discretionary Access Control

RBAC assigns permissions based on roles like admin or user.

In ABAC, access decisions are made based on:

A User attributes and rules

B Tokens or capabilities

C User roles only

D Fixed permissions

ABAC uses user attributes like age or location combined with rules.

What does Capability-Based Access Control use to grant permissions?

A User attributes

B Special tokens or capabilities

C User roles

D Passwords

It uses tokens that prove permission to perform actions.

Why is access control critical in smart contracts?

A To speed up transactions

B To allow anyone to change contract code

C To restrict sensitive actions to authorized users

D To increase blockchain size

Access control prevents unauthorized use of sensitive functions.

Which pattern is best when permissions depend on multiple user details like location and membership?

A Mandatory Access Control

B RBAC

C Capability-Based

D ABAC

ABAC uses multiple attributes to decide access.

Describe the main differences between RBAC and ABAC in blockchain access control.

Think about how permissions are decided in each pattern.

Explain why access control is essential for smart contracts and give an example of a risk without it.

Consider what could happen if anyone could call any function.