SECURE COMMUNICATION

Anita Maharjan

Basanta kadel

Bhoj Raj Kafle

Bijay Raj Paudel

INTRODUCTION

as we know in a network system, it is not possible that single user enjoy the whole system all alone.

because networking is used by most sector like banking,entertainment, commercial,educational,etc.

what we think of networking and what we want is

NETWORK SYSTEM

BUT ACTUALLY!!

Bankers

entertainer

educator

we Hackers!!

What is network security?

network security refers to any activities designed to protect your network.

Specifically, these activities protect the usability, reliability, integrity, and safety of your network and data.

Effective network security targets a variety of threats and stops them from entering or spreading on your network.

So, secure communication refers to a communication in secure network whereby only the recipient of the message understands the message, even if there are intruders who may intercept, read and perform computations on whatever is being transmitted.

Properties of Secure Communication in Networking

Confidentiality

Only the sender and the receiver should be able to understand the contents of the transmitted message. B

Because of intruders(eavesdropper), i.e. hackers, the message maybe encrypted (its data disguised) so that the interceptor cannot understand the message.

Attack at 9pm.  

12383084093.

$h34#88

1238308409

3. $h34#

88

Attack at

9pm.Move

Move

Authentication

Process of providing identity Can be classified into three main categories:

what do you know,

what do you have and

what you are

Username and Password

User to access the information is provided with unique user ID and password

Can be for users and for computers that share data Based on what you know

Tokens

Tokens are the security device that authenticates the user by having the appropriate permissions embedded into the token itself

Token can be cards, RF ID tags etc. Based on what you have

Biometrics

Uses the person’s unique character to authenticate them Based on what you are. Human characteristics that can be used for identification

includes: Fingerprint

Hand

Retina

Face

Voice, etc

Message integrity and nonrepudiation

 Even if the sender and receiver are able to authenticate each other, they also want to ensure that the content of their communication is not altered, either maliciously or by accident during transmission.

Therefore message integrity can be ensured by extensions to the checksumming techniques that we encounter in reliable transport and data link protocols.

The most common approach is to use

a one-way hash function that combines all the bytes in the message with a secret key and produces a message digest that is impossible to reverse.

 So the thing that will give the sender and the receiver the assurance,

 of untampered data is also a small fixed length data called MAC(Message authentication code).

How to generate a MAC(Message Authentication Code)?

Hash function is one of the method, that can be used to generate a message authentication code.

This is done with the help of a generating a hash value of secret key & and a message to be authenticated.

The message to be authenticated, can be of any length. But the output of the hash function done on the message, will be of fixed length.

this generated MAC, will also confirm the authenticity, because only the person that has the secret key can open that MAC value for verifying the data(as mentioned before the MAC is generated with the secret key value).

As mentioned, the sender and the receiver will negotiate a secret key, before beginning the communication. This is similar to symmetric encryption, where same keys are used to decrypt at both the ends.

mov

e

to

right

move

to right

30873.98890

critical case like in banking..

transfer $100 toaccount no.1239

9

transfer $1000

to account

no.12399

Availability and access control

 The compelling need for network security has been made unbearable over the past several years by numerous denial-of-access attacks that have rendered a network host or other pieces of network infrastructure unusable by legitimate users.

 The notion of access control ensures that entities seeking to gain access to resources are allowed to do so only if they have the appropriate access rights and perform their accesses in a well-defined manner

student

identity

cardonly acess

to external information like school

programs,information about courses,etc

acess to all information, internal as

well a external

principal

identity

card

Network Security

How are the Principles Implemented?

Layering

Passwords

Antivirus Softwares

Network PoliciesDoor LocksInformation

Limiting

Limiting access to information reduces threat Only those who must use data should have access to

it. The amount of access granted to someone must

should be limited to what the person needs to know or do.

Limiting Example

Obscurity

Obscuring what goes on inside a system or organization and avoiding clear patterns of behavior makes access from outside difficult.

Simplicity

Complex security system can be difficult to understand, troubleshoot and feel secure about

The aim is to make the system simple from inside and complex from the outside

Authentication

Process of providing identity Can be classified into three main categories:

what do you know (Username and Password),

what do you have(tokens, card)

what you are(biometrics)

In Summary

Properties of Secure Communication:ConfidentialityAuthenticationMessage IntegrityAccess Control

THANK YOU