Introduction (Pendahuluan)  Information Security

2  Information is a strategic resource  Information security requirements have changed in recent decades Traditionally provided by physical & administrative mechanisms Use of computer requires automated tools to protect files and other stored information Use of networks and communication links requires measures to protect data during transmission Information Security – Why?

3  Computer Security : generic name for the collection of tools designed to protect data and to thwart hackers  Network Security : measures to protect data during their transmission  Internet Security : measures to protect data during their transmission over a collection of interconnected networks Definition

4 3 aspects of information security:  Security Attacks  Security Services  Security Mechanisms

5 Security Attacks  Definition: Any action that compromises the security of information owned by an organization  Often threat & attack used to mean same thing  Threat : A potential for violation of security  Attack : An assault on system security that derives from an intelligent threat

6 Classification of security attacks  Passive Attacks: attempt to learn or make use of information from the system but does not affect system resources  Active Attacks: attempt to alter system resource or affect their operation

7 Security Threats  Threats can come from a range of sources  Various surveys, with results of order: 55% human error 10% disgruntled employees 10% dishonest employees 10% outsider access also have "acts of god" (fire, flood etc)  Note that in the end, it always comes back to PEOPLE.  Technology can only assist so much, always need to be concerned about the role of people in the threat equation - who and why.

8 Passive Attacks  Only involve monitoring (interception) of the information, leading to loss of confidentiality or  Traffic analysis (monitoring exchange of information without knowing precise contents),  hard to detect

9  Release of message contents: attacks confidentiality Eavesdropping Learn the content of transmitted messages

10  Traffic Analysis: attacks confidentiality, or anonymity Monitoring the pattern of transmitted messages  Include: the source & destination, frequency, and length of messages Determine the location and identity of communicating hosts

11 Active Attacks  Active attacks involve some modification of the data stream or the creation of a false stream, and  hard to prevent.

12 Masquerade  pretends to be a different entity

13 Replay  passive capture of a data unit and its subsequent retransmission to produce an unauthorized effect

14 Modification of messages  alters some portion of a legitimate message

15 Denial of service  prevents or inhibits the normal use or management of communications facilities

16 Security Services  Enhance security of data processing systems and information transfers of an organization  Intended to counter security attacks using one or more security mechanisms  Security services implement security policies  Often replicate functions normally associated with physical documents have signatures, dates need protection from disclosure, tampering, or destruction; be notarized or witnessed be recorded or licensed

17 Security Services  Authentication - protect info origin (sender)  Access control - control access to info/resources  Data Confidentiality - protect info content/access  Data Integrity - protect info accuracy  Non-repudiation - protect from deniability  Availability - ensure a system (info) is available to authorized entities when needed. One Useful Classification of Security Services:

18 Security Mechanisms  Features designed to detect, prevent, or recover from a security attack Personnel : Access Tokens, Biometrics Physical : Integrated Access Control Managerial : Security Education Data Networking : Encryption, Config. Control S/W & O/S : Testing, Evaluation, Trusted O/S.

19 Facts: security mechanism  No single mechanism can provide all the security services wanted.  But encryption or encryption-like information transformation (and hence the cryptography) is a key enabling technology