Transcript Data Confidentiality

Data Confidentiality
Learning Objectives:
By the end of this topic you should be able to:
• discuss the need to keep data confidential
• explain how data confidentiality can be
achieved;
Learning Objective:
By the end of this topic you should be able to:
• discuss how the following can be used to protect data:
– encryption,
– authorisation,
– authentication,
– virus checking,
– virus protection,
– physical security
Learning Objective (G061 synoptic)
• explain methods for combating ICT crime and
protecting ICT systems:
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physical security,
firewalls,
backup,
encryption,
biometric security,
software patches/updates,
‘anti-virus’ & antispyware software,
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access rights,
auditing,
education of users,
user IDs,
passwords
methods for ensuring
passwords remain
effective
Confidentiality
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is my data safe?
can I trust who has access to my data?
is my data correct?
can I be sure that my data will not be passed on?
Example:
• bank account information is highly confidential
– however, on-line banking takes place through the Internet
 an open network
 prone to attacks by hackers
Why does data need to be
kept confidential?
1. to comply with the Data Protection Act
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personal data must be kept secure
personal data must not be revealed
2. organisational reasons
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information maybe commercially sensitive
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details of new products or procedures
• of value to competitors
Encryption
What is Encryption?
• the process of disguising messages or data
– ‘scrambling’ data
– so that only the intended recipient can understand them
– if data accessed unlawfully, it will be meaningless to
unauthorised user
• involves data being ‘arithmetically transformed'
before transmission in a scrambled form.
– uses a random process set up using a special key value
– the data is then decoded at receiver
 by reversing the encryption process.
Encryption
Why use Encryption?
• to provide security of data
– especially during transmission through the Internet
– where it is liable to interception.
• so that sensitive data cannot be understood by criminals
– credit card details, emails
• to ensure that data of a sensitive nature can only be
accessed by those for whom data is intended
– to maintain privacy
• to protect important data that might be hacked or stolen
– music CD, movie DVD, digital TV
Authorisation
• giving permission (authority) for users to access data
• different users are allowed to access different data
– and/or perform different operations on data
Authorisation: Levels of Access
1. may want to restrict access to data
– only certain users can access the data
– so that unauthorised changes are not made
2. data is commercially valuable
– could be stolen or damaged/modified
3. legal restrictions on the access to personal data
– DPA
Authorisation: Levels of Access
• there are four main levels of access rights to data:
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Read Only: a user is allowed to view data
Create: a user is allowed to create new data records
Write: a user is allowed to make changes to data
Delete: a user is allowed to delete data
• to gain authorisation, a user must identify themself
• usually by entering a user name (User ID)
• other methods of supplying User IDs include:
– such as a magnetic stripe on the back of a card,
– a smart chip on a card,
– biometric: voice recognition, finger print, retina scan ….
Authorisation: User IDs
Why?
• allow access to user areas
– stop unauthorised access
– protect data
• to make individual users members of groups
– allow access to files based on access rights
– allow access to resources – printers, software
• to be able to monitor use
– audit logs
• to comply with the law
– DPA
Authorisation: User IDs
Effectiveness of user ID maintained by:
• must be unique
– so can be sure who is doing what
• can be suspended when user is away
– on holiday, leaves the company (or infringes code of conduct)
• can be linked to resources
– an individual machine
– software applications
– times of use
Authentication
• “the process of determining the identity and
legitimacy of a user or process”
– confirming that a user is who they say they are
Why:
• authorisation only tells the computer who the user is
• authorisation does not prevent somebody from
pretending to be a different person
• need a 2nd level of identification
Authentication
3 main ways for authenticating individuals:
• 'Something you know'
– password, PIN
• 'Something you have'
– mobile phone, credit card or hardware security token
• 'Something you are'
– biometric: voice recognition, fingerprint, retinal scan ….
Authentication: Password
Effectiveness of password maintained by:
1. Network Manager:
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force password change frequently
enforce minimum length password
enforce unrecognisable words only (not in dictionary)
must contain numbers and letters (& punctuations)
cannot reuse passwords
3 incorrect password attempts  account is locked
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not writing password down
make it something others can’t guess – not personal
make sure no one is looking when you type it in
Viruses
• a program which infects computer systems by selfreplicating (copying itself to other systems)
• computers can be infected by viruses when new data is
introduced to the computer:
– removable media: USB storage devices, memory cards, CD-R,
DVD-R
– across a network: LAN, via the Internet
• infection by a virus can:
– cause harm to data on a computer
– collect information about a user without the user’s knowledge
(spyware)
Boot Sector Viruses
• spreads by hiding itself in the boot sector your hard
drive or floppy disk.
• when your computer reads an infected floppy disk, the
virus is copied from the disk to your computer's
memory.
• any new disk, CD or memory stick inserted in the
computer will then become infected
• if this storage medium is used on another computer – it
becomes infected ……
E-mail Virus
• contained in attachments to e-mail messages,
• replicates itself by automatically mailing itself to
people in the victim's e-mail address book.
• spreads very rapidly
Trojan
• a computer program
• program claims to do one thing but instead does
damage when you run it
– delete files, erase hard disk
• opens your computer up to malicious intruders,
allowing them to read your files
• appears to be friendly – but isn’t!
Macro Virus
• many applications now have their own built-in
programming language (macro language)
– Microsoft Office applications use Visual Basic
• infects word processor files, spreadsheets, databases …
• can spread quickly
– if a Word file is sent via email
– file used by many people.
• Microsoft added protection into later versions of Word,
– now receive a warning about infected documents.
Virus Protection
• install anti-virus software on all computers
• scan storage devices for infected files
– detects viruses
– allows removal of infected code from file
– deletion of infected files
• regularly update virus data files
• install firewall on network
– hardware or software
• prevent use of removable storage media
– CDs, DVDs
– USB devices - memory stick, removable HDD
Audit Logs
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consist of data about each stage of any transaction,
logs are maintained automatically by the system
allow the network manager to examine patterns of use
audit logs track:
– who did what,
– at which workstation,
– when it occurred.
• logs can be used to see which member of staff:
– accessed particular files
– other resources
– web pages.
Firewall
• network security device
– stands between a network and the outside world
– can either be hardware and/or software based.
– examines data packets moving into and out of the system.
• configured to permit or deny connections
– using a set of rules
– access is denied if not allowed by the rules
– rules set using the organization's security policy
 configured by the system administrator
– checks data sent by users and applications
– filters websites users are permitted to visit
Why use a Firewall?
• prevents external users from gaining unauthorised
access to a computer system
• limits/filters the data that can be received or sent to
external users
• could block certain types of data
• to protect data from being viewed/altered/deleted
• to comply with the Data Protection Act
• to stop hackers/viruses from entering the system
January 2007
Physical Security
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lock the computer up
entry measure to get into building
disconnect (or remove) floppy/CD/DVD drives
disconnect USB ports (memory sticks/portable HDD)