CDN Access Control & Token Authentication

Question 1

What is the primary purpose of token-based URL signing in a CDN?

Accepted Answer

To ensure only authorized users can access protected content by embedding a cryptographic signature in the URL

Answer

To compress content before delivery to end users

Answer

To route requests to the nearest edge node automatically

Answer

To enable HTTP/2 push for static assets

Question 2

Which hashing algorithm is most commonly used to generate HMAC-based secure tokens in CDN implementations?

Accepted Answer

SHA-256

Answer

MD5

Answer

SHA-1

Answer

CRC32

Question 3

Hotlink protection in a CDN primarily works by checking which HTTP header on incoming requests?

Accepted Answer

Referer

Answer

Authorization

Answer

X-Forwarded-For

Answer

Cache-Control

Question 4

A signed CDN URL contains the parameter `exp=1719878400`. What does this value represent?

Accepted Answer

The Unix timestamp after which the token is no longer valid

Answer

The file expiration age in seconds

Answer

The number of allowed downloads for the URL

Answer

The cache TTL override in minutes

Question 5

Which of the following is an advantage of signed cookies over signed URLs for CDN access control?

Accepted Answer

Signed cookies allow access control across multiple files without modifying each individual URL

Answer

Signed cookies require less server-side computation to verify

Answer

Signed cookies are stored on the CDN edge rather than the client browser

Answer

Signed cookies bypass CDN caching entirely to improve security

Question 6

What happens at the CDN edge when a request arrives with an expired signed URL token?

Accepted Answer

The CDN returns a 403 Forbidden response

Answer

The CDN forwards the request to the origin to re-validate the token

Answer

The CDN strips the token and serves the content anyway

Answer

The CDN returns a 301 redirect to a login page automatically

Question 7

In CDN geo-restriction, which mechanism does the CDN use to determine a user's geographic location?

Accepted Answer

IP-to-geolocation database mapping the client's IP address to a country

Answer

GPS coordinates submitted by the user's browser

Answer

The user's self-declared country during account registration

Answer

The Accept-Language HTTP header sent by the browser