CHAPTER 6: SECURITY, PRIVACY AND DATA INTEGRITY

6.1 DATA SECURITY

6.1.1 Definitions

Data Security:

• Ensuring data is protected against loss and unauthorized access
• Protection of data on computer system

Data Integrity:

• Ensuring data is valid and does not corrupt after transmission
• Data is accurate and reliable

Data Privacy:

• Ability to determine what data is shared with third party

6.1.2 Threats to Computer and Data Security

Malware:

• Software designed to damage computer or network
• Virus: Replicates by inserting copy into other software; can crash computer, delete/corrupt data
• Spyware: Gathers information about users' activity; monitors online/offline behaviour

Hacking:

• Illegal access to computer system
• Obtain confidential data
• Can cause identity theft
• Can delete/corrupt data

Phishing:

• Emails attempting to obtain confidential data
• Impersonates legitimate organizations
• Causes identity theft

Pharming:

• Redirects users to fake websites
• Appears legitimate
• Gains confidential data

6.1.3 Security Measures

User Accounts and Passwords:

• Deny unauthorized access
• User-assigned privilege levels
• File access permissions

Firewalls:

• Filters information between computer and internet
• Detects illegal connection attempts
• Blocks unauthorized access

Authentication:

• Determines if someone is who they claim
• Methods: passwords, digital signatures, biometric scans

Anti-virus Software:

• Detects and removes viruses
• Checks files for malicious patterns
• Runs in background

Anti-spyware Software:

• Detects and removes spyware

Encryption:

• Converts data to code
• Doesn't stop access but makes data meaningless
• Requires decryption to read

Data Backup:

• Exact copy of original data
• Stored at different location
• Disk-mirroring: writes to multiple disks simultaneously

6.1.4 Data Security vs System Security

6.2 DATA INTEGRITY

6.2.1 Data Validation

Definition: Checks if data entered is valid (sensible).

Methods:

6.2.2 Data Verification

Definition: Checks data entered is accurate (correct).

Data Entry Verification:

Data Transfer Verification:

Parity Check:

• Number of 1s in byte must be odd or even
• If parity doesn't match, error detected
• Limitation: Cannot detect 2-bit transposition

Checksum Check:

• Data sent as block of bytes
• All bytes added together
• Checksum calculated before and after transmission
• If different, error occurred; block must be resent