Understanding AuthN and AuthZ in Object Storage Access Quiz

Test your knowledge of authentication (AuthN) and authorization (AuthZ) concepts in object storage, including signed URLs, short-lived tokens, and resource-level permissions. This quiz helps reinforce key distinctions and practical scenarios for secure storage access.

  1. AuthN vs AuthZ Basics

    Which term describes the process of verifying a user's identity before allowing any access to object storage resources?

    1. Authentication
    2. Access Control
    3. Assertion
    4. Authorization

    Explanation: Authentication is the process of verifying who a user is before granting access to any resource. Authorization occurs after authentication and determines what actions or resources the user can access. Access control is a broader term that includes authorization but not just identity verification. Assertion generally refers to a statement or claim, not verification of identity.

  2. Authorization Purpose

    In object storage, what does authorization typically control in a resource-level permission system?

    1. What actions a user can perform on specific objects
    2. How quickly users can access the service
    3. Which protocol is used for data transfer
    4. How much storage space a user has

    Explanation: Authorization in resource-level permission systems determines what actions, like reading or writing, a user can perform on specific objects. It does not decide how quickly users access the service, what protocol is used, or storage quotas. Those aspects may be managed elsewhere, but authorization focuses on actions and resources.

  3. Signed URLs Function

    What is the main purpose of using signed URLs to access objects in storage?

    1. Encrypting object data before storage
    2. Compressing large files for download
    3. Replicating data to multiple locations
    4. Granting temporary, restricted access without sharing credentials

    Explanation: Signed URLs allow temporary and restricted access to an object without needing to share credentials, effectively delegating access. They are not used for encrypting data, file compression, or data replication. These other functions address different aspects of data management.

  4. Short-Lived Tokens

    Why are short-lived tokens considered more secure for granting temporary object storage access compared to permanent credentials?

    1. They encrypt the files automatically
    2. They support faster data transfers
    3. They are easier to remember
    4. They expire quickly, reducing risk if exposed

    Explanation: Short-lived tokens are safer since they expire soon after issuance, limiting the window of potential misuse if leaked. They do not make data transfers inherently faster, are not meant to be memorized, and do not perform encryption by themselves. Their main advantage is temporary validity.

  5. Example Scenario: Signed URL

    If an application generates a signed URL allowing download of a photo for 10 minutes, which type of control is this an example of?

    1. Object encryption
    2. Permanent access control
    3. Protocol enforcement
    4. Authorization and temporary authentication

    Explanation: A signed URL combines temporary authentication (proving the request is allowed) and authorization (specifying what action is permitted and for how long). It is not permanent, does not define network protocol, nor does it encrypt the object. The URL specifies limited access and duration.

  6. Permission Example

    In a resource-level access system, allowing User A to list objects but not delete them from a bucket is an example of which practice?

    1. Least privilege
    2. Implied inheritance
    3. Token revocation
    4. Automatic replication

    Explanation: Granting only the minimum necessary permissions, such as allowing listing but not deletion, is called least privilege. Implied inheritance refers to permissions inherited from higher levels and is not specifically being described. Token revocation is about invalidating tokens, and replication involves copying data, unrelated to this scenario.

  7. AuthZ Failure Result

    What typically happens if a user successfully authenticates but lacks the required authorization for an object storage action?

    1. The object is deleted
    2. The authentication automatically fails
    3. The system encrypts the user's data
    4. Access to the action is denied

    Explanation: If authorization fails, the action is denied even if authentication was successful, keeping unpermitted actions secure. Authentication success does not retroactively fail. Objects are not deleted because of lack of authorization, and the system does not encrypt data as a response to permission issues.

  8. Resource-Level vs Bucket-Level

    Which statement best describes resource-level permissions in object storage?

    1. Permissions set at the level of individual files or objects
    2. Permissions only set for entire storage buckets
    3. User authentication using passwords
    4. Encryption methods based on object type

    Explanation: Resource-level permissions allow fine-tuned access controls on each object or file. By contrast, bucket-level permissions apply to the whole storage bucket. Authentication using passwords refers to identity verification, while encryption methods are a separate concept from authorization.

  9. Revoking Access

    Which method ensures a signed URL no longer provides access before its expiration time?

    1. Changing encryption settings
    2. Switching to a different protocol
    3. Removing or modifying the underlying object
    4. Increasing the token TTL

    Explanation: Removing or renaming the object invalidates the signed URL, as it points to a now-missing resource. Raising the token's time-to-live prolongs access, not removal. Changing encryption settings or protocols does not directly stop access via the signed URL.

  10. AuthN and AuthZ Together

    Which statement about the relationship between authentication and authorization in storage access is correct?

    1. Authentication precedes authorization
    2. Authorization occurs before authentication
    3. They are always performed together in a single step
    4. Authentication is optional if authorization is performed

    Explanation: Authentication must occur first to verify who is requesting access, after which authorization determines permissions. Authorization without authentication risks granting rights to unknown parties. They are not always one step, and authentication is not optional for secure authorization.

  11. Short-Lived Token Expiry

    What is the likely result if a user tries to access an object using a short-lived token that has already expired?

    1. The token is automatically renewed
    2. The user is granted limited access
    3. The object is permanently deleted
    4. Access is denied

    Explanation: If a token has expired, access attempts using it are denied to help maintain security. Automatic renewal does not happen unless explicitly implemented. There is no granting of limited access nor is the object deleted just because a token expired.

  12. Signed URL Usage Example

    An organization wants to let clients download a confidential report but not view other files. Which solution is suitable?

    1. Grant all clients full bucket access
    2. Disable all access controls
    3. Create a signed URL for just the report
    4. Provide permanent user passwords to clients

    Explanation: A signed URL provides access only to the specific report, preserving confidentiality for other objects. Giving full bucket access or permanent passwords is risky and over-scoped, while disabling access controls entirely threatens security.

  13. Revocation After Token Disclosure

    If a short-lived access token is accidentally exposed, what reduces the security risk the most?

    1. Short token expiration time
    2. Storing data in multiple regions
    3. Higher storage quotas
    4. Complex file naming

    Explanation: A short expiration time limits the period an attacker can use the token, making exposure less harmful. Data storage location, quota size, and file names do not inherently reduce the risk associated with a leaked token.

  14. Control Plane Responsibilities

    Which process is mainly responsible for verifying if a user can perform 'write' actions on an object after identity is confirmed?

    1. Authentication
    2. Replication
    3. Authorization
    4. Data retention

    Explanation: Authorization checks permissions for actions such as 'write' after authentication confirms identity. Authentication only establishes identity. Replication involves copying data, and data retention handles storage duration, not access rights.

  15. Signed URLs vs Permanent Credentials

    Why are signed URLs often preferred over permanent credentials for granting third-party access to specific objects?

    1. They limit access scope and validity period
    2. They offer unlimited storage space
    3. They guarantee higher download speeds
    4. They encrypt data automatically

    Explanation: Signed URLs restrict access to specific actions and time frames, enhancing security without exposing permanent credentials. They do not inherently encrypt data, speed up downloads, or influence storage capacity.