1. www.BZUPAGES.COM presentation on security issues in networking Presented by: Ayesha Yasin Nazish Yaqoob Kiran Shakoor Razeena Ameen

2. www.BZUPAGES.COM 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.

3. www.BZUPAGES.COM Fundamental concepts of network security: Objectives of network security Threats of network security Safeguards Attacks on network

4. www.BZUPAGES.COM Objectives of network security Network security has three major objectives are given below Confidentiality: Ensuring that information is not disclosed or revealed to unauthorized persons. Integrity:Assurance that data is not altered or destroyed in an unauthorized manner

5. www.BZUPAGES.COM Legitimate use: Ensuring that authorized persons don’t use the information in an unauthorized way.

6. www.BZUPAGES.COM 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 event Trojan horse programs : Delivery vehicles for destructive code, which appear to be harmless or useful software programs such as games

7. www.BZUPAGES.COM Vandals:Software applications or applets that cause destruction Eavesdropping:It is leakage of information by monitoring communication channels

8. www.BZUPAGES.COM 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

9. www.BZUPAGES.COM Authorized Violation: A person authorized to use resources uses it in unauthorized way.

10. www.BZUPAGES.COM 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

11. www.BZUPAGES.COM 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.

12. www.BZUPAGES.COM 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 :

13. www.BZUPAGES.COM 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

14. www.BZUPAGES.COM 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

15. www.BZUPAGES.COM 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.

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17. www.BZUPAGES.COM 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.

18. www.BZUPAGES.COM Functions of a firewall Three major functions of firewall are 1) Examine data 2) Filter data 3) Protect network from attacks

19. www.BZUPAGES.COM 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

20. www.BZUPAGES.COM 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.

21. www.BZUPAGES.COM 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.

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

23. www.BZUPAGES.COM 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.

24. www.BZUPAGES.COM 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.

25. www.BZUPAGES.COM “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.

26. www.BZUPAGES.COM 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.

27. www.BZUPAGES.COM 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.

28. www.BZUPAGES.COM 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.

29. www.BZUPAGES.COM 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

30. www.BZUPAGES.COM 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

31. www.BZUPAGES.COM Traditional way of cryptography

32. www.BZUPAGES.COM 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.

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34. www.BZUPAGES.COM 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

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36. www.BZUPAGES.COM 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

37. www.BZUPAGES.COM Three authentication measures Digital certificate Smart card Kerberos

38. www.BZUPAGES.COM 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

39. www.BZUPAGES.COM 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.

40. www.BZUPAGES.COM 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

41. www.BZUPAGES.COM Kerberos Kerberos uses three –pronged approach for authentication Database (contains user’s rights) Authentication server Ticket granting server

42. www.BZUPAGES.COM 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

43. www.BZUPAGES.COM 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