ECE 422 CS 461 Fall 2013 Acknowledgment Thanks to Susan Hinrichs for her slides Outline Administrative Issues Class Overview Introduction to Computer Security What is computer security ID: 579936
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Slide1
Introduction to Computer Security: Terminology, Security Policy
ECE 422 / CS 461 - Fall 2013
*Acknowledgment: Thanks to Susan
Hinrichs
for her slidesSlide2
Outline
Administrative IssuesClass OverviewIntroduction to Computer SecurityWhat is computer security?
Why computer security?
Computer security components
Introduction to security policy
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Staff etc.
StaffINSTRUCTORS:
David
Nicol
: First half (Roughly: Aug. 26 – Oct. 14)
Rakesh Bobba: Second half
(Roughly: Oct. 16 – Dec. 12)
TAs Balaji ManoharanTed PacygaOffice hours David Nicol (held when teaching; 451 CSL)TBDRakesh Bobba (held when teaching; 444 CSL)TBD
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Academic Honesty
Review department and university cheating and honor codes:
http://www.ece.illinois.edu/students/ugrad/academic-
honesty.html
https
://wiki.engr.illinois.edu/display/undergradProg/Honor+Code
http://admin.illinois.edu/policy/code/article1_part4_1-402.
html
Expectations
for exams,
homeworks, projects, and papersWhen in doubt, ask!
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Class Overview I – Format &Text
FormatMeets 2-times a week (MW)
Mostly lecture based
Text Books / Readings
Computer Security: Principles and Practice by William Stallings and Lawrie Brown 2
nd
Ed.
Additional ReadingsLinks and documents posted in CompassBooks on reserve at library1-5Slide6
Class Overview II – Lectures
Lecture Slides - DisclaimerNot intended to be self sufficient
Going through lecture slides will NOT be enough to master course material
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Class Overview III - Grades
2 midterms worth 20% each (total 40%)Tentatively:
October 2nd and November 6
th
Comprehensive Final worth 30%Date & Time:
December 16
th
8 -11 AM In class quizzes – 5%Homeworks & MPs 25% About 7 – 8 homeworks ; can drop lowest homeworkSubmit homeworks via Compass2gExtra project for grad. students (4 credits) 20%1-
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Class Overview IV -
Communication
Class web page
https://wiki.engr.illinois.edu/display/ece422sp13/ECE422+-+CS461+Computer+Security+I+Fall+
2013
Lecture
slides, schedule,
homeworksLecture Videos (For Online Students)https://wiki.engr.illinois.edu/display/ENGRonline/Fall+2013+CS+coursesCompass2gHomework submissions and grade distributionPiazzaFor discussionshttps://piazza.com/illinois/fall2013/cs461ece422/home
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Security Classes Roadmap I
3 Introductory/General CoursesComputer Security I (CS461/ECE422)
Covers NSA 4011 security professional requirements
Taught every semester (mostly)
Computer Security II (CS463/ECE424)Continues in greater depth on more advanced security topics
Taught every semester or so
Applied Computer Security Lab (CS460)
Generally taught in the springWith CS461 covers NSA 4013 system administrator requirementsTwo of the three courses will satisfy the Security Specialization in the CS track for Computer Science majors.1-9Slide10
Security Classes Roadmap
II
Theoretical
Foundations of
Cryptography (CS 498) & Applied Cryptography (CS 598 MAN)
Prof
Manoj
PrabhakaranAdvanced Applied Cryptography (ECE 598 NB) & Privacy Enhancing Technologies (ECE 598 NB)Prof Nikita BorisovCryptography (Math 595/ECE 559)Prof. BlahutMalware Analysis CS498SHSecurity Reading Group CS591RHCAdvanced Computer Security CS563Local talks
http://
www.iti.illinois.edu
/content/seminars-and-eventsITI Security Roadmaphttp://www.iti.illinois.edu/education/course-roadmaps/security1-10Slide11
ECE 422 / CS 461 Topics
First course in computer security at UIUCMix of motivation, design, planning, and mechanisms
Covers what, why and how of computer security
Breadth first look
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What is computer security?Why do we need it?
Art & science of protecting/securing computer systems?
Because we
need
to protect/secure computers from …. adversaries
Mischief makers (script kiddies)?
Hackers?
Hactivists?Ourselves (sometimes)….1-12Slide13
What is Computer Security?
“The protection afforded to an automated information system in order to attain the applicable objectives of
preserving the integrity, availability and confidentiality
of information system resources” (includes hardware, software, firmware, information/data, and telecommunications)
.”
NIST Security Handbook
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Key Security Notions/Concepts
ConfidentialityPreventing unauthorized access or disclosure
Keeping data confidential to authorized parties
Privacy (subtle difference)
IntegrityPreventing against unauthorized modifications
Data Integrity (integrity)
Origin Integrity (authentication)
AvailabilityEnsuring timely availability of (data, system service etc.)1-14Slide15
Additional Security Concepts
AuthenticityProperty of being genuine; can be verified
and trusted
Similar to authentication
AccountabilityRequirement for entity actions to be traced uniquely to that entity
Non-repudiation -- one cannot repudiate one’s actions
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Why is computer security challenging?
Both systems to be protected and security mechanisms can be quite complex and subtle
Security mechanisms themselves might become targets or introduce unintended weaknesses
A single weakness can bring down the system – defenders have to work harder
Systems, environments, and adversaries are constantly evolving/changing
Security often tends to be an afterthought rather than designed in
….
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Some Terminology
Threat
– Set of circumstances that has the potential to
breach security and cause harm
Vulnerability
– Weakness in the system that could be exploited to
violate security property of interest
Attack
– When an entity exploits a vulnerability on system
Control or Countermeasure – A means to prevent a vulnerability from being exploited; or minimize harm from the vulnerability/attack; or detect attack so recovering actions may be initiatedAdversary – threat agent1-17Slide18
Classes of Threats
Disclosure
– Unauthorized access to
information
Deception
– Acceptance of false
data
Disruption
– Interruption or prevention of correct operationUsurpation – Unauthorized control of some part of a system1-18What security property(ies) or concept(s) does each class violate?Slide19
Some common threats
Snooping or interception
Unauthorized interception of information
Falsification
Unauthorized change of information
Masquerading or spoofing
An impersonation of one entity by another
Repudiation
A false denial that an entity received some information
.
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Security Strategy
Specification/Policy
What does it mean to be secured in particular
?
Implementation/Mechanism
How to enforce the specified security policy?
Correctness/Assurance
Does the security system work as advertised1-20Slide21
Specification/Policy
Specification considerations
Security
vs.
ease of use
Return on investment – security business
case
Policy
A statement of what is and what is not allowed
Divides the world into secure and non-secure states
A secure system starts in a secure state. All transitions keep it in a secure state.
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Is this situation secure?
Web server accepts all connections
No authentication required
Self-registration
Connected to the Internet Slide23
Security Mechanism or Implementation
A
method, tool, or procedure for enforcing a security policy
Prevention
Detection
Response
R
ecovery
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Trust and Assumptions
Locks prevent unwanted physical access.
What are the assumptions this statement builds on?Slide25
Policy Assumptions
Policy correctly divides world into secure and insecure states.
Mechanisms prevent transition from secure to insecure states.
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Assurance
Evidence of how much to trust a system
Evidence can include
System specifications
Design
Implementation
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Aspirin Assurance Example
Why do you trust Aspirin from a major manufacturer?
FDA certifies the aspirin recipe
Factory follows manufacturing standards
Safety seals on bottles
Analogy to software assuranceSlide28
Slide #1-28
Key Points
Must look at the big picture when securing a system
Main components of security
Confidentiality
Integrity
Availability
Differentiating Threats, Vulnerabilities, Attacks and Controls
Policy
vs.
mechanism
AssuranceSlide29
Security Policy
A security policy is a formal statement of the rules by which people who are given access to an organization’s technology and information assets must apply. (RFC 2196)
Defines what it means for the organization to be in a secure state.
Otherwise people can claim ignorance.
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Question
University policy disallows cheating.Alice forgets to write protect her homework.
Bob copies it.
Who violated policy?
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Question Part 2
Alice posts her homework on the department bulletin board (or piazza).
Bob copies it.
Who is at fault with respect to policy?
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Mechanisms or Controls or Countermeasures
Entity or procedure that enforces some part of the security policy
Access controls (like bits to prevent someone from reading a homework file)
Disallowing people from bringing CDs and floppy disks into a computer facility to control what is placed on systems
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Hierarchy of Policy
Organizational
Policy
Departmental
Policy
Department
Standards
CSIL-Linux10
SE Linux Policy
Linux Lab
Umask settings
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Natural Language Security Policies
Targeting Humans
Written at different levels
To inform end users
To inform lawyers
To inform technicians
Users, owners, beneficiaries (customers)
As with all policies, should define purpose not mechanism
May have additional documents that define how policy maps to mechanism
Should be enduring
Don't want to update with each change to technology
Shows due diligence on part of the organization
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Key Parts of Organizational Policy
What is being protected? Why?
Generally how should it be protected?
Who is responsible for ensuring policy is applied?
How are conflicts and discrepancies to be interpreted and resolved?
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How to Write a Policy
Understand your environment
Risk Analysis (see next lecture)
Understand your industry
Look for “standards” from similar companies
Leverage others wisdom
Already proven with
auditors/regulators
Standards
ISO 17799 – Code of Practice for Information Security Management
COBIT – Control Objectives for Information and Related
Technolgy
SANS, CERT have policy guidelines
Gather
the right set of people
Technical experts, person ultimately responsible, person who can make it happen
Not just the security policy “expert”
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Security Policy Life Cycle
Risk Analysis
Policy Development
Reassessment
Policy Implementation
Raising Awareness
Policy Approval
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Security Policy Contents
Purpose – Why are we trying to secure things
Identify protected resources
Who is responsible for protecting
What kind of protection? Degree but probably not precise mechanism.
Cover all cases
Realistic
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More Specific Policy Content Ideas
Principles of SecurityOrganizational Reporting Structure
Physical Security
Hiring, management, firing
Data protectionCommunication securityHardware
Software
Operating systems
Technical supportPrivacyAccessAccountabilityAuthenticationAvailabilityMaintenanceViolations reportingBusiness continuitySupporting information
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University of Illinois Information Security Policies
University of Illinois Information Security Policies
System wide policy; Identifies what, not how
http://www.obfs.uillinois.edu/cms/one.aspx?pageId=914038
CITES UIUC standards and guidelines
DNS
–
http://
www.cites.uiuc.edu/dns/standards.html
CS Department
policies
https://wiki.engr.illinois.edu/display/tsg/Policies
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Example Privacy policies
Busey
Bank
https://www.busey.com/home/fiFiles/static/documents/privacy.pdf
Financial Privacy Policy
Targets handling of personal non-public data
Clarifies what data is protected
Who the data is shared with
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Poorly Written Policies
Cars.gov – Had following in click-through policy for
dealers
This
application provides access to the [Department of Transportation] DoT CARS system. When logged on to the CARS system, your computer is considered a Federal computer system and is the property of the U.S. Government. Any or all uses of this system and all files on this system may be intercepted, monitored, recorded, copied, audited, inspected, and disclosed... to authorized CARS, DoT, and law enforcement personnel, as well as authorized officials of other agencies, both domestic and foreign.
According to
EFF
http
://www.eff.org/deeplinks/2009/08/cars-gov-terms-service
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Example Acceptable Use Policy
IEEE Email Acceptable Use Policy
http://eleccomm.ieee.org/email-aup.shtml
Inform user of what he can do with IEEE email
Inform user of what IEEE will provide
Does not accept responsibility of actions resulting from user email
Does not guarantee privacy of IEEE computers and networks
Examples of acceptable and unacceptable use
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Key Points
Security policy bridges between human expectations and implementation reality
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