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AN INTRODUCTION OF COMPUTER SECURITY AND PRIVACY

Hacking:
  • Hacking is the process of gaining unauthorized access to a computer system for fun and challenge of it.


EcoleBooks | COMPUTER A LEVEL(FORM SIX) NOTES - AN INTRODUCTION OF COMPUTER SECURITY AND PRIVACY
Hackers:
  • Hackers are people who gain unauthorized access to a computer for fun and challenge of it.
WHAT IS COMPUTER SECURITY?
EcoleBooks | COMPUTER A LEVEL(FORM SIX) NOTES - AN INTRODUCTION OF COMPUTER SECURITY AND PRIVACY
EcoleBooks | COMPUTER A LEVEL(FORM SIX) NOTES - AN INTRODUCTION OF COMPUTER SECURITY AND PRIVACY
WHY IS IT IMPORTANT?
? Information is power and money
? Computer systems manage information and provide mission-critical support for business, government, and financial institutions
WHY IS HACKING SO BAD?
EcoleBooks | COMPUTER A LEVEL(FORM SIX) NOTES - AN INTRODUCTION OF COMPUTER SECURITY AND PRIVACY
Hacker can view your private information.
-Hacker can edit your data.
-Hacker can misuse other personal information.
-Can damage systems e.g. E- Bank system.
-Can steal money through network.


Computers are everywhere
? Computer systems constantly grow in complexity (and size)
? Today’s networks are very heterogeneous, and critical components are often connected (maybe in indirect ways) to non-critical, poorly managed computer systems
? People make mistakes in both the development and the deployment of computer systems
EcoleBooks | COMPUTER A LEVEL(FORM SIX) NOTES - AN INTRODUCTION OF COMPUTER SECURITY AND PRIVACY
Home Users Increase Vulnerabilities
Today most homes are connected, particularly with the advent of DSL and cable modems
Most home users:
? Are unaware of vulnerabilities
? Don’t use firewalls
? Think they have nothing to hide or don’t care if others get their data
? Don’t realize their systems can serve as jump off points for other attacks (zombies or bots)
Computer security is reactive
? usually reacting to latest attack
? offense is easier than defense
Security is expensive both in dollars and in time .There is not now, and never will be, a system with perfect security.
EcoleBooks | COMPUTER A LEVEL(FORM SIX) NOTES - AN INTRODUCTION OF COMPUTER SECURITY AND PRIVACY
SECURITY INCIDENTS
Who are the attackers?
? Script kiddies download malicious software from hacker web sites
? Hackers trying to prove to their peers that they can compromise a specific system
? Insiders are legitimate system users who access data that they have no rights to access
? Organizational level attackers use the full resources of the organization to attack
After September 11, 2001 the idea of nation State level cyber attacks being carried out by Terrorists became a big concern more recently, most attacks are financially motivated. There is a complete cyber underground economy
EcoleBooks | COMPUTER A LEVEL(FORM SIX) NOTES - AN INTRODUCTION OF COMPUTER SECURITY AND PRIVACY
Types of computer security
1. Physical Security/Hardware security
2. Network security/Software security
3. Data security
1. Physical Security:is the protection a hardware, data, networks form physical harm like thief. Hardware security refers to practices regarding how physical devices and computer hardware are handled and overseen to protect them from physical harm like theft.
EcoleBooks | COMPUTER A LEVEL(FORM SIX) NOTES - AN INTRODUCTION OF COMPUTER SECURITY AND PRIVACY
EcoleBooks | COMPUTER A LEVEL(FORM SIX) NOTES - AN INTRODUCTION OF COMPUTER SECURITY AND PRIVACY

? Lock up the server room
Even before you lock down the servers, in fact, before you even turn them on for the first time, you should ensure that there are good locks on the server room door. Of course, the best lock in the world does no good if it isn’t used, so you also need policies requiring that those doors be locked any time the room is unoccupied, and the policies should set out who has the key or key code to get in.
The server room is the heart of your physical network, and someone with physical access to the servers, switches, routers, cables and other devices in that room can do enormous damage.
? Set up surveillance
Locking the door to the server room is a good first step, but someone could break in, or someone who has authorized access could misuse that authority. You need a way to know who goes in and out and when. A log book for signing in and out is the most elemental way to accomplish this, but it has a lot of drawbacks. A person with malicious intent is likely to just bypass it.
A better solution than the log book is an authentication system incorporated into the locking devices, so that a smart card, token, or biometric scan is required to unlock the doors, and a record is made of the identity of each person who enters.
A video surveillance camera, placed in a location that makes it difficult to tamper with or disable (or even to find) but gives a good view of persons entering and leaving should supplement the log book or electronic access system. Surveillance cams can monitor continuously, or they can use motion detection technology to record only when someone is moving about. They can even be set up to send e-mail or cell phone notification if motion is detected when it shouldn’t be (such as after hours).
EcoleBooks | COMPUTER A LEVEL(FORM SIX) NOTES - AN INTRODUCTION OF COMPUTER SECURITY AND PRIVACY
Make sure the most vulnerable devices are in that locked room
Remember, it’s not just the servers you have to worry about. A hacker can plug a laptop into a hub an
d use sniffer software to capture data traveling across the network. Make sure that as many of your network devices as possible are in that locked room, or if they need to be in a different area, in a locked closet elsewhere in the building.
? Use rack mounts servers
Rack mount servers not only take up less server room real estate; they are also easier to secure. Although smaller and arguably lighter than (some) tower systems, they can easily be locked into closed racks that, once loaded with several servers, can then be bolted to the floor, making the entire package almost impossible to move, much less to steal.
? Don’t forget the workstations
Hackers can use any unsecured computer that’s connected to the network to access or delete information that’s important to your business. Workstations at unoccupied desks or in empty offices (such as those used by employees who are on vacation or have left the company and not yet been replaced) or at locations easily accessible to outsiders, such as the front receptionist’s desk, are particularly vulnerable.
Disconnect and/or remove computers that aren’t being used and/or lock the doors of empty offices, including those that are temporarily empty while an employee is at lunch or out sick. Equip computers that must remain in open areas, sometimes out of view of employees, with smart card or biometric readers so that it’s more difficult for unauthorized persons to log on.
? Keep intruders from opening the case
Both servers and workstations should be protected from thieves who can open the case and grab the hard drive. It’s much easier to make off with a hard disk in your pocket than to carry a full tower off the premises. Many computers come with case locks to prevent opening the case without a key.
You can get locking kits from a variety of sources for very low cost, such as the one at Innovative Security Products.
? Protect the portables
Laptops and handheld computers pose special physical security risks. A thief can easily steal the entire computer, including any data stored on its disk as well as network log on passwords that
may be saved. If employees use laptops at their desks, they should take them with them when they leave or secure them to a permanent fixture with a cable lock, such as the one at PC Guardian.
Handhelds can be locked in a drawer or safe or just slipped into a pocket and carried on your person when you leave the area. Motion sensing alarms such as the one at Security Kit.com are also available to alert you if your portable is moved.
For portables that contain sensitive information, full disk encryption, biometric readers, and software that “phones home” if the stolen laptop connects to the Internet can supplement physical precautions.
? Pack up the backups
Backing up important data is an essential element in disaster recovery, but don’t forget that the information on those backup tapes, disks, or discs can be stolen and used by someone outside the company. Many IT administrators keep the backups next to the server in the server room. They should be locked in a drawer or safe at the very least. Ideally, a set of backups should be kept off site, and you must take care to ensure that they are secured in that offsite location.
Don’t overlook the fact that some workers may back up their work on floppy disks, USB keys, or external hard disks. If this practice is allowed or encouraged, be sure to have policies requiring that the backups be locked up at all times.
? Disable the drives
If you don’t want employees copying company information to removable media, you can disable or remove floppy drives, USB ports, and other means of connecting external drives. Simply disconnecting the cables may not deter technically savvy workers. Some organizations go so far as to fill ports with glue or other substances to permanently prevent their use, although there are software mechanisms that disallow it. Disk locks, such as the one at Security Kit.com, can be inserted into floppy drives on those computers that still have them to lock out other diskettes.
? Protect your printers
You might not think about printers posing a security risk, but many of today’s printers store document contents in their own on-board memories. If a hacker steals the printer and accesses that memory, he or she may be able to make copies of recently printed documents. Printers like servers and workstations that store important information, should be located in secure locations and bolted down so nobody can walk off with them.
Also think about the physical security of documents that workers print out, especially extra copies or copies that don’t print perfectly and may be just abandoned at the printer or thrown intact into the trash can where they can be retrieved. It’s best to implement a policy of immediately shredding any unwanted printed documents, even those that don’t contain confidential information. This establishes a habit and frees the end user of the responsibility for determining whether a document should be shredded.
Summary
EcoleBooks | COMPUTER A LEVEL(FORM SIX) NOTES - AN INTRODUCTION OF COMPUTER SECURITY AND PRIVACY
2. Network security/Software security
?Enable Encryption Use 128-bit of encryption or higher. There are two different types of encryption WEP and WPA.WEP is weak and can be cracked easily within few minutes with software’s available online.WPA is strong and uses TKIP encryption while WPA2 uses AES which is stronger than WPA.
?Enable MAC Address filtering :
Address will only allow specific devices to access the network. You can disable or permit certain MAC address to access the network.
? Disable Remote Log in: Remote log in can give anyone access to router setting remotely. This can be worst if an attacker tries to brute force router access and you’re still using the default username and passwords. By default it’s disabled on every router. Enable it only if you’re updating your router remotely and disable it after the update is done.
? Change SSID: Change the default SSID name of your network. The SSID is the identifier name which identifies your network, so you can connect to it. Using the default SSID name will know that the router was setup by a novice and the attacker will try to brute force. This
will make it worst, if you ‘reusing a default password.
? Set password for router Change the default password of the router. Use a random long password that cannot be easily guessed like include small letter, caps letter, numbers and special characters. That makes it Georgian College.
EcoleBooks | COMPUTER A LEVEL(FORM SIX) NOTES - AN INTRODUCTION OF COMPUTER SECURITY AND PRIVACY
Fig:Show dilalogue box for setting passward to route.
? Secure and managing the network server. – Install the server software on a dedicated host or on a virtual machine to test the software before installing it on the main server. – Create a logical partition for server data and remove software which are not required like gopher or FTP. And install server content on separate drive. – Configure the server to listen only on TCP and UDP ports. – Set an upload limit on the server, if your organization needs to upload files. Ensure that there is some software which scans the uploaded file before uploading on the server.
Configure the max number of connection. You might not want your server to get a DOS attack. – Check the server logs regularly and check if there was any intrusion or any suspicious activity. – Protect the log files, so if an attacker attacks the server, the attacker cannot get access to the log files to alter the data. –
? Back up your server regularly, so if any worst condition arises, you can always restore your server.
3. Data security:
Refers to ways in which attacks can be launched on data streams and software, without physical interaction of different devices or hardware.
?Access control: Access to confidential data must be provided on a least-privilege basis. No person or system should be given access to the data unless required by business process. In such cases where access is required, permission to use the data must be granted by the Data Steward
? Sharing: Protected data may be shared among the among University employees according to well-defined business process approved by the Data Steward. It may be released publicly only according to well-defined business processes, and with the permission of the Data Steward.
? Retention: Confidential data should only be stored for as long as is necessary to accomplish the documented business process.
? Incident Notification: If there is a potential security incident that may place protected data at risk of unauthorized access, Its Technology Security Services must be notified:
? Transit encryption: Restricted data must be encrypted during transmission
? Storage encryption: Restricted data must be encrypted using strong, public cryptographic algorithms and reasonable key le
ngths given current computer processing capabilities. Keys must be stored securely, and access to them provided on a least-privilege basis (see ISO 11568 for recommendations on securing keys).

TYPES OF COMPUTER THREATS
EcoleBooks | COMPUTER A LEVEL(FORM SIX) NOTES - AN INTRODUCTION OF COMPUTER SECURITY AND PRIVACY
Password Guessing
i. Exhaustive search for passwords
ii. Lists of commonly used passwords
iii. Distributed default passwords
iv. Password cracking programs readily available on the Internet.
? Spoofing :Duping a user into believing that he is talking to the system and revealing information
(E.g. password).
? Browsing :After an intruder has gained access to a system he may peruse any files that are available for reading and glean useful information for further penetrations
? Often done by legitimate users
? Denial of Service :Prevention of authorized access to computer resources or the delaying of time-critical operations
? Masquerading: Gaining access to the system under another user’s account.
? Leakage: Transmission of data to an unauthorized user from a process that is allowed to access the data.
? Tampering: Making unauthorized changes to the value of information Accidental Data Destruction Unintentional modification of information.
? Trojan Horse :A program that does more than it is supposed to do
? More sophisticated threat
? A text editor that sets all of your files to be publicly readable in addition to performing editing functions
? Every unverified program is suspect (especially games)
EcoleBooks | COMPUTER A LEVEL(FORM SIX) NOTES - AN INTRODUCTION OF COMPUTER SECURITY AND PRIVACY
? Trap Door :A system modification installed by a penetration that opens the system on command
? May be introduced by a system developer
? Bogus system engineering change notice
? Virus: A program that can infect other programs by modifying them to include a possibly evolved copy of itself.
EcoleBooks | COMPUTER A LEVEL(FORM SIX) NOTES - AN INTRODUCTION OF COMPUTER SECURITY AND PRIVACY
TERMINOLOGIES
Confidentiality – Keeping data and resources hidden or protected from unauthorized disclosure
Integrity – Ensures that the data and programs are modified or destroyed only in a specified and authorized way
? Data integrity (integrity)
. Origin integrity (authentication )
Availability – ensures that the resources of the system will be usable whenever they are needed by an authorized user.
Browsing: Searching through main and secondary memory for residue information
Leakage: Transmission of data to an unauthorized user from a process that is allowed to access the data Inference: Deducing confidential data about an individual by correlating unrelated statistics about groups of individuals
COMPUTER SECURITY THREATS
EcoleBooks | COMPUTER A LEVEL(FORM SIX) NOTES - AN INTRODUCTION OF COMPUTER SECURITY AND PRIVACY
Fig:Show various computer security threats.
EcoleBooks | COMPUTER A LEVEL(FORM SIX) NOTES - AN INTRODUCTION OF COMPUTER SECURITY AND PRIVACY
ACC
ESS CONTROL
A means of limiting a user’s access to only those entities that the policy determines should be accessed
EcoleBooks | COMPUTER A LEVEL(FORM SIX) NOTES - AN INTRODUCTION OF COMPUTER SECURITY AND PRIVACY
EcoleBooks | COMPUTER A LEVEL(FORM SIX) NOTES - AN INTRODUCTION OF COMPUTER SECURITY AND PRIVACY
METHOD, TOOL, OR PROCEDURE TO ENFORCE A SECURITY POLICY.
EcoleBooks | COMPUTER A LEVEL(FORM SIX) NOTES - AN INTRODUCTION OF COMPUTER SECURITY AND PRIVACY
APPROACHES TO SECURITY
1. Procedural
2. Functions and Mechanism
3. Assurance
1. Procedural Approaches: Prescribe appropriate behavior for a user interacting with the system
– Periods processing
– Guidelines for managing passwords
– Appropriate handling of removable storage devices
– Electronic voting systems

– Periods Processing: Split the day into periods and run different classification jobs in each period
2. Functions and Mechanisms: Enforce security policy
Examples are the 3As
Authentication: assures that a particular user is who he/she claims to be
Access control: a means of limiting a user’s access to only those entities that the policy determines should be accessed
Audit: a form of transaction record keeping. The data collected is called an audit log
3. Assurance
EcoleBooks | COMPUTER A LEVEL(FORM SIX) NOTES - AN INTRODUCTION OF COMPUTER SECURITY AND PRIVACY
1. Penetration Analysis
Uses a collection of known flaws, generalizes the flaws, and tries to apply them to the system being analyzed
Penetration team known as “Tiger Team”
– Demonstrates the presence not the absence of protection failures
2. Covert Channels
Covert channel – Uses entities not normally viewed as a data object to transfer information
Two Types of Covert Channels
?Storage channels – The sender alters the value of a data item and the receiver detects and interprets the altered value to receive information covertly
? Timing channels – The sender modulates the amount of time required for the receiver to perform a task or detect a change in an attribute, and the receiver interprets the delay or lack of delay to receive information covertly.
3. Formal verification: Is the act of proving or disproving the correctness of intended algorithms underlying a system with respect to a certain formal specification or property, using formal methods of mathematics.
PRIVACY
Privacy – ensures that only the information that an individual wishes to disclose is disclosed.


INTERNET PRIVACY
The ability to control what information one reveals about oneself over the Internet, and to control who can access that information.

EcoleBooks | COMPUTER A LEVEL(FORM SIX) NOTES - AN INTRODUCTION OF COMPUTER SECURITY AND PRIVACY
SOFTWARE SECURITY:
EcoleBooks | COMPUTER A LEVEL(FORM SIX) NOTES - AN INTRODUCTION OF COMPUTER SECURITY AND PRIVACY
1. Use a firewall
A firewall is software or hardware that checks information coming from the Internet or a network and then either turns it away or allows it to pass through to your computer, depending on your firewall settings. In this way, a firewall can help prevent hackers and malicious software from gaining access to your computer.
Windows Firewall is built into Windows and is turned on automatically.
EcoleBooks | COMPUTER A LEVEL(FORM SIX) NOTES - AN INTRODUCTION OF COMPUTER SECURITY AND PRIVACY
How a firewall works
If you run a program such as an instant messaging program or a multiplayer network game that needs to receive information from the Internet or a network, the firewall asks if you want to block or unblock (allow) the connection. If you choose to unblock the connection, Windows Firewall creates an exception so that the firewall won’t bother you when that program needs to receive information in the future.

2. USE VIRUS PROTECTION/ ANTIVIRUS

Viruses, worms, and Trojan horses are programs created by hackers that use the Internet to infect vulnerable computers. Viruses and worms can replicate themselves from computer to computer, while Trojan horses enter a computer by hiding inside an apparently legitimate program, such as a screen saver. Destructive viruses, worms, and Trojan horses can erase information from your hard disk or completely disable your computer. Others don’t cause direct damage, but worsen your computer’s performance and stability.
Antivirus programsE‑mail and other files on your computer for viruses, worms, and Trojan horses. If one is found, the antivirus program either quarantines (isolates) it or deletes it entirely before it damages your computer and files.
Windows does not have a built-in antivirus program, but your computer manufacturer might have installed one. If not, there are many antivirus programs available. Microsoft offers Microsoft Security Essentials, a free antivirus program you can download from the Microsoft Security Essentials website. You can also go to the Windows 7 security software provider’s website to find a third-party antivirus program.
Because new viruses are identified every day, it’s important to use an antivirus program with an automatic update capability. When the program is updated, it adds new viruses to its list of viruses to check for, helping to protect your computer from new attacks. If the list of viruses is out of date, your computer is vulnerable to new threats. Updates usually require an annual subscription fee. Keep the subscription current to receive regular updates.

WARNING: IF YOU DON’T USE ANTIVIRUS SOFTWARE, YOU EXPOSE YOUR COMPUTER TO DAMAGE FROM MALICIOUS SOFTWARE. YOU ALSO RUN THE RISK OF SPREADING VIRUSES TO OTHER COMPUTERS.

3. USE SPYWARE PROTECTION

Spyware is software that can display advertisements, collect information about you, or change settings on your computer, generally without appropriately obtaining your consent. For example, spyware can install unwanted toolbars, links, or favorites in your web browser, change your default home page, or display pop-up ads frequently. Some spyware displays no symptoms that you can detect, but it secretly collects sensitive information, such as the websites you visit or the text you type. Most spyware is installed through free software that you download, but in some cases simply visiting a website results in a spyware infection.
To help protect your computer from spyware, use an anti spyware program. This version of Windows has a built-in anti spyware program called Windows Defender, which is turned on by default. Windows Defender alerts you when spyware tries to install itself on your computer. It also can scan your computer for existing spyware and then remove it.
Because new spyware appears every day, Windows Defender must be regularly updated to detect and guard against the latest spyware threats. Windows Defender is updated as needed whenever you update Windows. For the highest level of protection, set Windows to install updates automatically

4. UPDATE WINDOWS AUTOMATICALLY

Microsoft regularly offers important updates to Windows that can help protect your computer against new viruses and other security threats. To ensure that you receive these updates as quickly as possible, turn on automatic updating. That way, you don’t have to worry that critical fixes for Windows might be missing from your computer.
Updates are downloaded behind the scenes when you’re connected to the Internet. The updates are installed at 3:00 A.M. unless you specify a different time. If you turn off your computer before then, you can install updates before shutting down. Otherwise, Windows will install them the next time you start your computer.

5. TO TURN ON AUTOMATIC UPDATING

A. Open Windows Update by clicking the Start buttonEcoleBooks | COMPUTER A LEVEL(FORM SIX) NOTES - AN INTRODUCTION OF COMPUTER SECURITY AND PRIVACY. In the search box, type Update, and then, in the list of results, click Windows Update.
B. Click Change settings.
C. Make sure Install updates automatically (recommended) is selected.
D. Windows will install important updates for your computer as they become available. Important updates provide significant benefits, such as improved security and reliability.
E. Under Recommended updates, make sure they Give me recommended updates the same way I receive important updates check box is selected, and then click OK.
F. Recommended updates can address non-critical problems and help enhance your computing experience. EcoleBooks | COMPUTER A LEVEL(FORM SIX) NOTES - AN INTRODUCTION OF COMPUTER SECURITY AND PRIVACY If you’re prompted for an administrator password or confirmation, type the password or provide confirmation.

6. CREATE USER ACCOUNTS

When you log on to your computer, Windows grants you a certain level of rights and privileges depending on what kind of user account you have. There are three different types of user accounts: standard, administrator, and guest.
Although an administrator account provides complete control over a computer, using a standard account can help make your computer more secure. That way, if other people (or hackers) gain access to your computer while you’re logged on, they can’t tamper with the computer’s security settings or change other user accounts. You can check your account type after you log on by doing the following:
4. Backup Your Data
To save yourself heartache you should regularly backup the data on the computer. A full system backup is recommended but with large hard drives that are available today this is not always practical. For large hard drives it is recommended that you at the least backup the files that you create (ie letters, documents, spreadsheets, accounting package data files, email etc). For steps on how to backup your computer please see our article on “Computer System Backups”.
5. Defragment your Hard Drive
As you start to create and delete files and applications on your computer the hard drive will become fragmented. This means that the data is split into chunks and stored in different areas of the hard disk. The more fragmented your drive is, the less efficient your computer operates. Defragmentation consolidates the separate chunks, frees up disk space and speeds up your computer.

To perform this task, first open up My Computer, select the drive you wish to defragment and press the right mouse button. Select Properties and then the Tools tab, press the button to start the Defragmenter program.




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EcoleBooks | COMPUTER A LEVEL(FORM SIX) NOTES - AN INTRODUCTION OF COMPUTER SECURITY AND PRIVACY

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