---
title: "Properties/attributes of secure communication"
subject: "Computer Networks and Security"
chapter: 8
key: "semester_7/computer_networks_and_security:secure-communication-properties"
source: https://www.bctengineer.com/q/semester_7/computer_networks_and_security/secure-communication-properties
site: BCT Engineering
---

# Properties/attributes of secure communication

Computer Networks and Security · Chapter 8: Network Security

- Asked in: 2074 Asoj, 4 marks; 2073 Chaitra, 4 marks (asked 2 times)
- Video: [CIA Properties | Confidentiality, Integrity, Availability with examples](https://www.youtube.com/watch?v=lswzFfs-peo) — Gate Smashers
- Answer checked by Claude Opus 5.5 (high effort) on 2026-10-14
- Page: https://www.bctengineer.com/q/semester_7/computer_networks_and_security/secure-communication-properties
- Whole chapter: https://www.bctengineer.com/md/semester_7/computer_networks_and_security/chapter-8

## Question

Explain briefly the desirable properties of secure communication (attributes of information security).

## Short answer

Confidentiality (encryption), integrity (hash/MAC), authentication (certificates), non-repudiation (digital signature), and availability/access control ensure secure communication, protecting messages from eavesdropping, alteration, impersonation, and denial.

## Answer

For two parties to communicate securely over an insecure network, the communication should have the following properties (the attributes of information security).

| Property | Meaning | Mechanism |
|---|---|---|
| **Confidentiality** | Only the sender and the intended receiver can understand the message; an eavesdropper sees only unreadable data | Encryption (AES, RSA) |
| **Integrity** | The message is not altered in transit, or any alteration is detected | Hash functions, MAC, digital signature |
| **Authentication** | Both parties are sure of the identity of the other (no impersonation) | Passwords, certificates, digital signatures |
| **Non-repudiation** | A sender cannot later deny sending a message | Digital signature |
| **Availability** | Network and data are accessible to authorised users when needed | Redundancy, firewalls, DoS protection |
| **Access control / authorisation** | Only permitted users can use a resource | ACLs, roles |

Example: Alice sends a payment order to the bank. Encryption keeps the amount secret, a hash detects a changed amount, a certificate shows that the bank is genuine and Alice's signature prevents her denying the order later.

## Check yourself

The answer's key points as multiple-choice questions, with the correct option and why.

1. Which mechanism provides confidentiality?
   A. Encryption
   B. Redundancy
   C. Hash functions
   D. ACLs
   Answer: A. Encryption makes the message unreadable to eavesdroppers. (Key point: Confidentiality)

2. How is a changed message detected?
   A. Passwords
   B. Encryption alone
   C. Backup
   D. Hash functions, MAC or digital signature
   Answer: D. Integrity mechanisms detect alteration in transit. (Key point: Integrity)

3. What does non-repudiation prevent, and which mechanism gives it?
   A. DoS; firewall
   B. Modification; ACL
   C. The sender denying sending; digital signature
   D. Eavesdropping; encryption
   Answer: C. A digital signature stops the sender denying the message later. (Key point: Non-repudiation)

4. Which property is protected by redundancy and DoS protection?
   A. Availability
   B. Integrity
   C. Authentication
   D. Confidentiality
   Answer: A. Availability means resources are accessible to authorised users when needed. (Key point: Availability)

## Related in Computer Networks and Security

- [Routing Information Protocol (RIP)](https://www.bctengineer.com/question.md?key=semester_7%2Fcomputer_networks_and_security%3Arip-protocol) — Computer Networks and Security, chapter 4
- [Web and file server communication](https://www.bctengineer.com/question.md?key=semester_7%2Fcomputer_networks_and_security%3Aweb-file-server-communication) — Computer Networks and Security, chapter 6
- [Encryption types and PGP](https://www.bctengineer.com/question.md?key=semester_7%2Fcomputer_networks_and_security%3Aencryption-types-pgp) — Computer Networks and Security, chapter 8

## Related in other subjects

- [Desirable properties of subgrade soil](https://www.bctengineer.com/question.md?key=semester_6%2Ftransportation_engineering_i%3Asubgrade-properties) — Transportation Engineering I, chapter 6, asked 11×
- [Desirable properties of road aggregates](https://www.bctengineer.com/question.md?key=semester_6%2Ftransportation_engineering_i%3Aaggregate-desirable-properties) — Transportation Engineering I, chapter 6, asked 5×
- [Desirable properties of bituminous mixes](https://www.bctengineer.com/question.md?key=semester_6%2Ftransportation_engineering_i%3Abituminous-mix-desirable-properties) — Transportation Engineering I, chapter 6, asked 3×
- [Desirable properties of heating elements](https://www.bctengineer.com/question.md?key=semester_7%2Futilization_of_electrical_energy%3Aproperties-heating-elements) — Utilization of Electrical Energy, chapter 5, asked 2×