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Security Chapter 8Objectives
• Societal impact of information and information technology
– Explain the meaning of terms related to computer security and crime and determine ways to protect both a business and yourself
– Identify areas of computer security vulnerability and ways to protect against them
– Recall the definition of encryption and apply the XOR encryption technique
– Recognize good and bad passwords based on password guidelines
Security Resources you can use
• Protecting your computer sound byte:http://wps.prenhall.com/bp_evans_techinaction_1/0,8697,1105530-,00.html
• Norton AntiVirus Response Center Web Page
http://securityresponse.symantec.com/• Test the vulnerability of your computer:
– Gibson Research Corporation (http://www.grc.com)
– Qualys (http://browsercheck.qualys.com/)
Computer security vulnerability points
• Hardware –
• Software –
• People –
Backup
• Data and Files are vulnerable
• Primary defense against data loss
• Selective, incremental & full
Software
• Perform regular updates
• http://update.microsoft.com for Windows
• Microsoft update: Windows, Office, more
• Automatic updates
• Check with vendors for updates
• Verify e-mail notices independently
Hackers
• Def:
• Types of hackers:– White-hat– Black-hat– Script kiddies
What Hackers Do
• Steal information from computers:– Credit card numbers– Bank account numbers
• Internet packet sniffing• Commit identity theft• Create widespread computer attacks:
– Backdoor programs (Trojan horse)
• Denial of service attacks
How Hackers Gain Access
• Direct access:– Hacking software
• Indirect access:– Internet connection
Firewall• Def:
• Types of firewalls:– Norton Personal Firewall– McAfee Firewall– Zone Alarm– BlackICE PC Protection– Network routers
Computer Viruses
• What puts you at risk for viruses?
How to "Catch" a Virus
• Email attachments. Do not open attachments before checking– Is this email from someone I know?– Is the message a sensible follow-up to the last
message from the sender?– Is the content of the message something the sender
would say to me?– Is there a reason for the sender to include an
attachment?
• When in doubt, be cautious
Antivirus Software• Def:
– Scan files looking for virus signatures (unique code)
– Provide options for deleting or fixing infected files
• Need to be updated frequently
• Examples: McAfee, Norton, and Sophos, Inc.
What Viruses Do
• Replicate themselves:– Slow down networks
• Display annoying messages
• Delete files
• Change computer settings
Love Letter – Fastest spreading virus
Melissa – Caused $80 million damage
Nimda – Affected more than 1 million computers
Logical security
Def:
What are ways to protect your password?
Biometric identification systems
– Fingerprint– Palm print– Iris scan– Face recognition technology
Encryption
• Def:
• Encrypted data can be safely stored or transmitted
• Why is this needed?
Encryption example
• Using Exclusive OR, XOR, If bits are the same, result is 0; if different 1
Apply a key to the plain or clear text
Encryption example
0101 Cleartext (The hex digit 5)
1001 Key
Encryption example
• If the cleartext is the hex digit D and the XOR key is 1001, what is the encrypted text?
Encryption example
• Encrypt the word NO with the key 10110110
Assignment
• Using XOR and the key 10110110, determine the encrypted results for the ASCII text: PASSWORD
• Complete HTML3