Cybersecurity: TCP vs UDP

Sometimes, being safe means being slow.
That happens in networking too.

Today, we focus on a key idea: why TCP is reliable but slower, and when you should pick UDP instead.

What is a protocol?

A protocol is a set of rules that define how devices communicate over a network. Like speaking the same language!

TCP (Transmission Control Protocol)

Here’s how it works:

• every data packet is sent only after the previous one is confirmed;

• if something goes wrong, the packet is re-sent.

• ✅ Reliable connection: ensures data is delivered in order and complete.

• ✅ Error checking: missing data is re-sent.

• ✅ Used for: websites (HTTP), email (SMTP), file transfers (FTP).

⚠️ Downside: it’s slower, because it checks everything.

Metaphor: Like sending a certified letter with return receipt. You know it arrived.

UDP (User Datagram Protocol)

It doesn’t wait for confirmations, and skips error checking.

• ⚡ Fast connection: no guarantees about delivery.
• ⚠️ No error checking: packets can be lost.
• ✅ Used for: streaming, VoIP, online gaming.

⚠️ Downside: no guarantee the data arrives, or that it’s in order.

Metaphor: Like mailing a postcard—you send it, but may not know if it arrives.

🎮 Real example: live video lessons

Let’s say you’re building a live e-learning platform.

With TCP, the stream may stutter every time a packet is lost.
With UDP, the video stays smooth, even if a frame or two gets lost.

📌 In this case, better to lose a bit than to lag a lot.

Why does it matter for cybersecurity?

Many attacks take advantage of UDP’s weaknesses:

• spoofing (impersonation),
• flooding (packet storms),
• sniffing (eavesdropping on data).

Summary

❓ 5 multiple-choice questions

1. Which protocol guarantees the order of packets?

   • A) UDP
   • B) TCP
   • C) HTTP
   • D) FTP

2. For smooth video calls, which protocol is better?

   • A) TCP
   • B) UDP
   • C) SSH
   • D) SMTP

3. UDP is best when:

   • A) You can’t tolerate delays
   • B) You want confirmations
   • C) You need encryption
   • D) You want something lightweight and fast

4. The main problem with UDP is:

   • A) It’s slow
   • B) It repeats data
   • C) It lacks control
   • D) It’s expensive

5. When sending critical data over TCP, you can expect:

   • A) Maximum speed
   • B) Ordered and complete delivery
   • C) Lost packets
   • D) No confirmation

✅ Answers

1. B
2. B
3. D
4. C
5. B