Which statement best describes end-to-end versus hop-by-hop integrity?

• A. End-to-end integrity protects the entire message through the chain; hop-by-hop validates each segment between nodes, potentially allowing differences
• B. End-to-end validates each hop, while hop-by-hop validates the entire path
• C. Both terms mean the same thing
• D. End-to-end is only for security, not integrity

Answer: (A)

Integrity across a network means the data you send should arrive unchanged, no matter how many devices it passes through.

End-to-end integrity uses a mechanism that covers the entire message from sender to final recipient. The final recipient can verify the whole payload (and often important headers) with a value created by the sender. If anything changes anywhere on the path, the end-to-end check will fail, catching tampering across the entire route.

Hop-by-hop integrity, on the other hand, checks each link between two adjacent nodes. Each segment is verified as it passes from one hop to the next, but the verification focuses only on that individual hop. Because the integrity check is localized to each segment, it’s possible for differences to exist between the original message and what the final recipient ends up with, even though every hop’s check passed in its own domain.

So the statement captures that end-to-end protects the entire chain, while hop-by-hop verifies each segment and may allow differences to accumulate across hops. The other options misstate who does what or claim they’re the same, or incorrectly separate integrity from security in this context.