Security and Privacy

Security and Privacy

Viruses • Not all programs that cause damage are viruses • Computer viruses share two characteristics with their biological counterparts • they require a host; they are not complete programs but pieces of code that become attached to (infect) another program • they replicate (copy) themselves

Types • boot sector infector: virus affecting the boot program (recall that booting is loading the operating system) • program or file infector: attaches to a program (typically has a .exe or .com extension)

Types (cont.) • macro virus: • a macro is a small program that automates repeated tasks in an application (like Word or Excel) • Macro  virus • a macro virus is a macro used to cause damage • example: Melissa

Bombs and worms • A logic bomb is designed to cause its damage only when a particular condition is met, a special case is a time bomb which goes off at a particular time • e.g. the Michelangelo virus • a worm does not attach itself to another program but fills one’s disk space (memory) with copies of itself

Protection • do not download and run software of questionable origin • install and run an anti-viral utility such as Norton Anti-virus on floppies and on hard drives • Update it frequently • do not have a floppy in the A drive when starting (booting) the computer • disable macros of unknown origin

Unauthorized access and use • Unauthorized access: logging on and using a computer without consent • hacker: one who gains unauthorized access to computers • Unauthorized use: sometimes the user is legitimate but the activity is not, e.g. playing games or downloading certain material or receiving/sending private email at work

Protection against unauthorized access • passwords • should be relatively long • should be a combination of letters and numbers (and symbols if allowed) • should be something you can remember and nobody else can guess • should not be shared • should be committed to memory and not written down on or near the PC

More on passwords • Windows NT (2000) has better password protection than Windows 95 because it was designed as a genuine multi-user operating system • For extra protection, add a password at the BIOS level

Other examples • ATM cards are used to authenticate users and to identify which accounts (files) he or she has access to; there is typically a password or personal identification number (PIN) as well • biometric devices: fingerprint or retina scanner, voice recognition, etc. • better protection • more expensive

Cryptography • one way to secure data, be it in storage or in transit, is encryption • Encryption coverts information in its usual readable form (called plaintext) to information in an encoded, unreadable form (called cyphertext) • PGP (Pretty Good Privacy) program: a good encrypter that works with most email systems

Keys • a key is a formula that encodes information • Single key cryptography uses one key; i.e. encryption and decryption method known to sender and receiver • Public-key cryptography uses two keys:(more secure) • public key: anyone can have used to encrypt • private key: only you have, used to decrypt

Digital signature • use this process in reverse • you can use your private key to encrypt a message • then anyone with your public key can decrypt it • BUT he or she knows who sent it • encryption and digital signatures are what makes secure transactions over the net possible

Encryption controversy • Government should have control over encryption, i.e. be able to decode it • PRO: aid FBI and such in fight against espionage, terrorism, drugs, etc. • CON: if government has this capability, there are those who will use it illegally; it’s no security at all

Gone but not forgotten • Deleting a file is not the end of it • Remember to empty the recycle bin • Even emptying the recycle bin or (quick) reformatting a disk does not completely eliminate your information • Only when the disk space is written over is the information truly disposed of

YOU’RE NOT PARANOID THEY REALLY ARE WATCHING YOU!

Data mining • data mining is collecting information available on a person or group of people • often done for targeted marketing • once a tedious chore, now easily done with computers • They’ll know you by your social security number

Your Privacy Quotient • (from PC World Sept. 1998) • Registered to vote • Bought a house • Had a baby • Owned substantial stock in a company • Given more than $50 to a campaign • Had your dog vaccinated for rabies • Taken out a permit for a yard sale • Paid a fine for an overdue library book

Privacy Quotient (cont.) • Gotten a parking ticket • Participated in a phone survey • Mailed in a warranty card • Entered a contest or sweepstakes • Used your ATM card for any purchase • Rented a movie • Subscribed to a magazine

At work • Electronic supervision: the computer at work can be used to keep track of your activity and/or productivity • email at work is not private; unless explicitly stated otherwise your employer can look at your email • the LAN manager can easily look at your files

The Cookie Monster • a cookie is information about your having visited a web site stored in YOUR computer • you can eliminate or block future cookies • browsers typically keep a list of sites visited, sometimes saved from session to session • it requires work to cover your surfing tracks

Software Piracy • “buying” software does not entitle the purchaser to copy and distribute, doing so is called “software piracy” • Billions of dollars every year, especially rampant in Asia • Public domain: software you are free to use in any way, you should still credit the source

More • Site license: permission for a school or company to run software from a network so one does not need a license for each computer • Plagiarism: claiming another’s work as your own, it may be code, research, writing, music, etc.

References • Discovering Computers 2000 (Shelly, Cashman and Vermaat) • Information Technology: The BreakingWave (Curtin, Foley, Sen, Morin) • PC World, Sept. 1998

Security and Privacy