What is Computer Security?

Computer Security is a branch of technology known as information security as applied to computers. Information security means protecting information and information systems from unauthorized access, use, disclosure, disruption, modification, or destruction. The objective of computer security varies and can include protection of information from theft or corruption, or the preservation of availability, as defined in the security policy.

Technological and managerial procedures applied to computer systems to ensure the availability, integrity and confidentiality of information managed by the computer system

 

Computer security imposes requirements on computers that are different from most system requirements because they often take the form of constraints on what computers are not supposed to do.

Typical approaches to improving computer security can include the following:



Physically limit access to computers to only those who will not compromise security.

Hardware mechanisms that impose rules on computer programs, thus avoiding depending on computer programs for computer security.

Operating system mechanisms that impose rules on programs to avoid trusting computer programs.

Programming strategies to make computer programs dependable and resist subversion.



Computer Security has three Layers:

o Hacking

o Cracking

o Phreaking

 

Hacking:

Unauthorized use or attempts to circumvent or bypass the security mechanisms of an information system or network.

Computer hacking always involves some degree of infringement on the privacy of others or damage to computer-based property such as files, web pages or software. The impact of computer hacking varies from simply being simply invasive and annoying to illegal.

 

Cracking:

The act of breaking into a computer system.

Software Cracking is the modification of software to remove protection methods: copy prevention, trial/demo version, serial number, hardware key, CD check or software annoyances like nag screens and adware.

The most common software ***** is the modification of an application’s binary to cause or prevent a specific key branch in the program’s execution.

 

Phreaking:

The art and science of cracking the phone network.

 

 

Security by design:

The technologies of computer security are based on logic. There is no universal standard notion of what secure behavior is. “Security” is a concept that is unique to each situation. Security is extraneous to the function of a computer application, rather than ancillary to it, thus security necessarily imposes restrictions on the application’s behavior.

There are several approaches to security in computing; sometimes a combination of approaches is valid:



Trust all the software to abide by a security policy but the software is not trustworthy (this is computer insecurity).

Trust all the software to abide by a security policy and the software is validated as trustworthy (by tedious branch and path analysis for example).

Trust no software but enforce a security policy with mechanisms that are not trustworthy (again this is computer insecurity).

Trust no software but enforce a security policy with trustworthy mechanisms.



 

12 tips for computer security:



Update / patch ALL your software every now and then!

Check / adjust ALL your settings so they are safe, since they ARENT by default!

Use firewall, like ZoneAlarm to control what goes in and out from your computer!

Use good passwords: at least 13marks long, containing both letters and numbers. Remember to change your password every few months atleast and dont ever use the same password in two places!

Get a good antivirus program: NOD32, F-Secure or Norton Antivirus and keep it updated!

Don’t open or execute files that you are not 100% sure are absolutely safe nomatter where or how you get them.

Wipe your historyfiles (like cookies, internet history and temporary files, etc.), logs and personal files, with specific wiping program (like Eraser) instead of just deleting them.

Use encryption to enhance your privacy! Use encrypted email (like Hushmail or Ziplip), www-surfing and encrypt sensitive files on your computer (PGP).

When you are finished using some internet-based service like email, sign out of it rather than just closing your browser! Also, when you leave your computer, make sure that none of such programs or connections are left open that someone could abuse. In WindowsNT/2k/XP, press Windowskey+L to lock the workstation.

Don’t use public computers for anything you need to type in your logins, they usually have Trojan horses that capture your passwords.

Make backups and store them in safe place! Easiest way to do a total-backup is to make an “Image” of your harddrive or partition and store it on safe location, but floppies will usually be just fine for storing documents, etc.

Install and Use a Hardware Firewall



 

Regards,

Kethy Wright

www.perceptionsystem.com

Nowadays desktops and laptops are much more durable and dependable that they were just five years ago. Therefore, buying a used or refurbished computer is becoming more of a trend.

Suppliers replace their computers on average every 6 months and companies frequently upgrade their equipment. Buying one of these used or refurbished computers can save you a lot of money while still using a quite up to date technology. This is even more relevant if you are not a heavy user (i.e. most of your time on a computer is spent online, you may use a few standard applications once in a while). Even modestly priced computers will more than suffice for these types of demand.

Thinking about buying a used or refurbished desktop or laptop?

Buying a computer is not at all an easy job, one has look get detailed information of the available computers of good and reputed brands. One must take into consideration the size, color, configurations, features etc… While your computer should correspond to your personality and lifestyle, you should always keep in mind the reputation of the brand in the market. Brand counts a lot; you can render good service by the manufacturer if your computer is damaged.

Important handy Tips before buying a computer…

* Verify if the brand is reputed and always buy a good reputed brand. Read about customer service experience for that specific computer issues.

* Check the warranty/guarantee of the computer (seek out computers which still have warranty/guarantee remaining)

* Compare the price of the new model in the market with what price your buying your used computer, try to get the best bargain. i.e. a two year old computer should not be bought for more than half of its original price.

* Check if the computer is outdated (if out of production it is difficult to get spare parts)

* Is the operating system current (Windows Vista/Windows Xp). Earlier versions probably run slower (windows 2000) and would not be advisable unless your needs are limited (i.e. web surfing, Word…). In any event, stay away with computers running on Windows 98 (granted you don’t find many anymore). Also be aware of Windows Vista. Many users are reverting back to XP and that is even more obvious in the corporate world. Why? Vista looks nice but doesn’t bring many technical improvements; therefore IT managers are not willing to implement something new when what they have works just fine. Some domestic users just don’t like the new way of navigation within the Vista Operating System.

* Check if the configuration of the computer you are buying is good.

* Check the speed of the processor. If possible start the computer and see how long it takes to fully turn on. If its slow just turning on, imagine the lack of speed once you start adding software..

Additional Tips for laptops

* Is the battery life good? (search for the computers with a very good battery backup).

* Check for the screen size of the computer your buying and see to it that it is not exceeding the Normal (normally the screen size should be between 15-17). Less than that generally translates in older computers and increases the chance of age failure. Once the screen breaks, you are often better of changing the whole computer.

* Review the connectivity of the computer (Network, USB, Video, Audio…) look to it that it has a good connectivity including wireless.

* Check out the weight. Ensure the computer is light enough for you to carry.

* More details at http://www.bestlaptopsreviews.com/index.php/Used-Notebooks.html

Where to buy used computers:

* Online auctions. Pro: Often offer the best prices. Cons: Cannot validate the accuracy of the described item. No warranty. Tip 1: Some companies will offer warranty for up to two years, the cost is about 12% to 18% of the purchase price. Tip2: Buy from sellers with great feedback, do not hesitate to contact the seller with questions prior to bidding.

* Online marketplaces: Pro: Set prices and quantities – Sometime warranty is available. Cons: Prices can vary a lot, do your homework.

* http://Craiglist.com Contacting sellers on http://Craiglist.com in your local area gives you a chance to meet with the owner and physically test the computer before the purchase

Where to buy refurbished computers:

Refurbished computers can be a great way to buy as they have warranties and are generally sold by manufacturers or companies affiliated with them.

* Manufacturers websites will tell you how to buy directly from them or from their authorized sellers. Pros: Warranty, established companies. Cons: Prices are higher than regular auctions (you pay more for peace of mind)

Buying a used or refurbished computer can be a great way to save money. If you use some of the advice discussed above you can avoid many pitfalls. One last thing concerning laptops, make sure you have a good bag to protect your computer from a fatal accident. Your bag should be big enough for a 17 inch screen computer as it is rapidly becoming the norm, you will probably change your computer within a few years, the bag you may keep a lot longer.

Good Buy!