TCP Data Integrity

Understanding TCP mechanisms for payload integrity verification

This medium-difficulty networking question tests your familiarity with the practical safeguards built into the TCP protocol stack. It probes whether you understand which specific technique TCP relies on to detect corruption or tampering of the data being transmitted between endpoints.

To answer questions in this area, you need to distinguish between the different layers of protection in the TCP/IP model—particularly the role of checksums versus cryptographic hashing, and where each operates in the protocol hierarchy. Interviewers are checking whether you can identify the standard mechanism that TCP itself employs, as opposed to optional or application-layer approaches.

• Checksum computation and validation at the transport layer
• Header versus payload protection in TCP
• Detection versus prevention of corruption
• The role of lower-layer (link-layer) error checking