Www.BZUPAGES.COM presentation on security issues in networking Presented by: Ayesha Yasin Nazish...

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security issues in networking

Presented by:Ayesha Yasin

Nazish YaqoobKiran Shakoor

Razeena Ameen


What is network security?

In simple words ,security has been defined as “protecting information system from unauthorized access”

Network security is defined as the proper safeguarding of all components associated with the network, including data, media, hardware, software and networks.


Fundamental concepts of network security:

Objectives of network security

Threats of network security

Safeguards

Attacks on network


Objectives of network security

Network security has three major objectives are given belowConfidentiality: Ensuring that information is not disclosed or revealed to unauthorized persons.Integrity:Assurance that data is not altered or destroyed in an unauthorized manner


Legitimate use:

Ensuring that authorized persons don’t use the information in an unauthorized way.


Threats of network security

Threats include in the network security :Viruses:Computer programs written by programmers and designed to replicate themselves and infect computers when triggered by a specific eventTrojan horse programs : Delivery vehicles for destructive code, which appear to be harmless or useful software programs such as games


Vandals:Software applications or applets that cause destruction

Eavesdropping:It is leakage of information by monitoring communication channels


Information leakage: Information is revealed to unauthorized users which is threat to secrecy

Repudiation: A person participating in an exchange of information denies having participated


Authorized Violation: A person authorized to use resources uses it in unauthorized way

.


Safeguards

Safeguards are physical controls ,security policies and procedures that protect networks from threats.

The following types of the safeguards are used in the network security

Scanners: Most antivirus software is a scanner, which scans viruses


Behavior blockers: This utility remains in the memory and alerts the user of any suspicious activity

Identifying services:These services help to identify users and control their activities and transactions on the network. Services include passwords,digital certificates, and digital authentication keys.


Attacks on network

There are different types of attacks

Viruses and worms

IP spoofing:The attacker changes the IP

address on message packets to that of another user or host machine

:


Brute force attacks :An attacker tries all possible passwords ,one at a time in the

hope to uncover the correct password Denial of service attack:

attacks occurs when servers are flooded with recursive queries in an attempt to prevent the server from servicing client requests. A successful DoS attack can result in the unavailability of services, and in the eventual shut down of the network


Man in the middle:A man-in-the-middle (MITM) attack occurs when a hacker eavesdrops on a secure communication session and monitors, captures and controls the data being sent between the two parties which is communicating


What is a firewall?

A device installed between the internal network of an organization and rest of the internet to provide security.

A firewall is a combination of hardware or software that sits between the internet and internal organization to protect the network from outside attack.


What can be a firewall?

A firewall can be a router, PC, a server or a collection of such devices.

It may be a hardware device or a software program running on a secure host computer.


Functions of a firewall

Three major functions of firewall are

1) Examine data

2) Filter data

3) Protect network from attacks


Types of firewalls

There are five generally accepted types of firewalls used on internet connections:

1) Frame-filtering firewalls

2) Packet-filtering firewalls

3) Circuit gateway firewalls

4) “Stateful” firewalls

5) Application gateways or proxies firewalls


Frame-filtering Firewalls

A frame-filtering firewall has the ability to filter to the bit level layout.

By providing filtering at this level frames that do not belong on the trusted network are rejected before they reach anything valuable even on the firewall itself.


Packet-filtering firewalls

A packet-filtering firewall is either a router with packet-filtering capabilities or a dedicated devices that does packet-filtering.

It operate on the data link and network layers.

Following fields within packets can be filtered:

1) The type of the packet such as IP,TCP,UDP.

2) IP source and destination address.

3) TCP/UDP sources and destination ports.


Packet filtering inspects each packet passing through the network and accepts or rejects it based on user-defined rules.


Circuit gateway firewalls

A circuit gateway firewall typically involves the session setup between a system and the user security options relative to that system for a particular user.

It check the user IDs and password for a connection request.

Circuit firewalls are also responsible for logging who came from where and went to what.


This is useful for hiding information about protected networks.

It can cut of any connection which is hijacked by a hacker trying to pass through the firewall.


“Stateful” firewalls

• This firewall combines the aspects of the other three types of firewalls.

• It is concerned with the need to examine the transaction condition between two interoperating applications becomes essential to defeating certain sophisticated types of network attacks.

• This type of firewall can help prevent attacks which exploit existing connections, or certain Denial-of-service attacks.


Information traveling from inside the firewall to the outside is monitored for specific defining characteristics, then incoming information is compared to these characteristics.

If the comparison yields a reasonable match ,the information is allowed through. Otherwise it is discarded.


Application gateways or proxies firewalls

It provides protection at the application level.It applies security mechanisms to specific applications, such as FTP and Telnet servers.In principle application firewalls can prevent all unwanted outside traffic from reaching protected machines.


In contrast to packet filter firewall it filter the request rather than packets entering or leaving the network.

It can block any FTTP or HTTP request.


Cryptography

Cryptography is technique of converting a message into un-understandable form such that even if some unauthorized person intercepts the message he would not be able to make any sense out of it


Encryption

The process of encoding a message

Decryption

The process of decoding a message

Unencrypted data is referred as plain text

Encrypted data is called cipher text


Traditional way of cryptography


Secret key cryptography

With ,secret key cryptography a single key is used for both encryption and decryption. the sender uses the key to encrypt the plaintext and sends the cipher text to the receiver. The receiver applies the same key to decrypt the message and recover the plaintext. Because a single key is used for both functions, secret key cryptography is also called symmetric cryptography.With this form of cryptography, it is obvious that the key must be known to both the sender and the receiver; that, in fact, is the secret.


Public key cryptography

In public key cryptography two keys are used one is public key which is available to everyone is used to encrypt message. Other is private key which remains secret and is not given to anyone, is used to decrypt message

Also called asymmetric cryptography


Authentication and access control

Authentication is a security measure. it is a process of verifying a claimed identity. the concept of authentication is similar to providing someone access to a secure area


Three authentication measures

Digital certificate

Smart card

Kerberos


Digital certificates

An attachment to an electronic message used for security purposes. The most common use of a digital certificate is to verify that a user sending a message is who he or she claims to be, and to provide the receiver with the means to encode a reply. An individual wishing to send an encrypted message applies for a digital certificate from a Certificate Authority (CA). The CA issues an encrypted digital certificate containing the applicant's public key and a variety of other identification information


The CA makes its own public key readily available through print publicity or perhaps on the Internet. The recipient of an encrypted message uses the CA's public key to decode the digital certificate attached to the message, verifies it as issued by the CA and then obtains the sender's public key and identification information held within the certificate. With this information, the recipient can send an encrypted reply.


Smart card are similar to credit card, a smart card has integrated circuit embedded in it.It use identification numbers, biometric(fingerprints, voice,signature) to authenticate a user. smart card can be used as cash card, telephone card, credit card etc


Kerberos

Kerberos uses three –pronged approach for authentication

Database (contains user’s rights)

Authentication server

Ticket granting server


How it works

Let’s assume we want to access a data file stored on one of our company server. when we first log on and request access to this file, an authentication server searches its database for our access right. when server confirms that we have permission to access these files, it generates an encrypted ‘ticket’ which enables our workstation to access ticket-granting server. the authentication server also returns key which was used to encrypt message called ‘authenticator’ our workstation then sends ticket and authenticator to ticket granting server


Which decrypt both pieces of data. if they match, ticket-granting server generates a ticket for the requested service to be used only by us. this ticket is then returned to our workstation, which we present to company’s server on which file is stored. when server receives our ticket, it gives access to the file

Www.BZUPAGES.COM presentation on security issues in networking Presented by: Ayesha Yasin Nazish...

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