ECT 582 Secure Electronic Commerce

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ECT 582Secure Electronic Commerce

• Professor Robin Burke

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Introductions

• About me
• http//josquin.cs.depaul.edu/rburke/
• About you
• Student information sheet

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Resources

• Course on-line
• discussion forum
• grades
• Course home page

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Security

• freedom from danger, risk, etc. safety
• freedom from care, apprehension or doubt
  well-founded confidence
• something that secures or makes safe protection
  defense
• precautions taken to guard against theft,
  sabotage, the stealing of military secrets, etc
• Websters Encyclopedic Unabridged Dictionary of
  the English Language

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E-Commerce

• the process of electronically buying and selling
  goods, services and information, and the
  maintenance of all the relationships, both
  personal and organizational, required for an
  electronic marketplace to function.

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What are we securing?
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Post-9/11 realities

• Aspects of business operations may impact public
  safety
• E-commerce opens a hole for interacting with an
  organization

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What can we do to improve security?
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Key concepts

• Risk
• Trust

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Risk

• What are the possible losses we are guarding
  against?

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Trust

• Must choose where trust is to be placed

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Risk management

• Risk analysis
• Risk mitigation
• Risk transfer

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What are the primary risks?

• Disclosure of proprietary information
• Denial of service
• Virus attacks
• Insider net abuse
• Financial fraud
• Sabotage
• - CSI/FBI 2003 Computer Crime and Security Survey

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Disclosure of Proprietary Info

• Customer data exposure
• Data theft
• Sensitive information

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Fraud

• Payment account abuse
• Transfer funds without authorization
• Destroy or hide financial records
• Customer impersonation

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Secondary risks

• Damage to relations with customer or business
  partners
• Legal, public relations, or business resumption
  cost
• Public relations damage
• Uptake failure due to lack of confidence

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How is e-commerce different?

• Need for physical proximity
• Differences in document

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Physical documents

• Semi-permanence of ink embedded in paper fibers
• Particular printing process
• letterhead
• watermark
• Biometrics of signature
• Time stamp
• Obviousness of modifications, interlineations,
  and deletions

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Computer documents

• Computer-based records can be modified freely and
  without detection
• Supplemental control mechanisms must be applied
  to achieve a level of trustworthiness comparable
  to that on paper
• Less permanent, too

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Legal differences

• In some cases, possession matters
• negotiable document of title
• cash money

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Attack

• Any action that compromises the security of
  information systems
• Normal flow

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Interruption

• Attack on availability

Info source
Info destination
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Interception

• Attack on confidentiality

Info source
Info destination
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Modification

• Attack on integrity

Info source
Info destination
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Fabrication

• Attack on authenticity

Info source
Info destination
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Passive vs active

• Passive
• Monitor communication
• Disclose contents
• but also traffic analysis
• Active
• Interfere with communication

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Active attacks masquerade

• Masquerade one entity pretends to be a different
  entity
• Example Session Hijacking
• Taking over an existing active session.
• It can bypass the authentication process and gain
  access to a machine

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Active attacks replay

• Passive capture of data
• Later retransmission to produce an unauthorized
  effect
• Example Password sniffing
• Program capture user id / password info
• Case in Tokyo sniffer installed at Internet
  cafe. 16 million Yen stolen.

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Active attacks modification

• Some portion of a legitimate message is altered,
  or that message are delayed or reordered, to
  produce an unauthorized effect
• Example Spam
• Return-To header on spam email is always forged
  to prevent tracking the sender

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Active attacks DoS

• Denial of service
• prevents or inhibits the normal use or management
  of communication facilities
• Example SYN flooding
• send open request for TCP connection but dont
  respond to handshake
• do this over and over again

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Security properties

• What do we want out of a secure e-commerce
  system?
• Confidentiality
• Authentication
• Integrity
• Non-repudiation
• Access control
• Availability

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Confidentiality

• Protects against interception
• Ensures that a message is only readable by
  intended recipient
• Technology
• Encryption

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Authentication

• Protects against fabrication
• Ensures that the origin of a message or
  electronic document is correctly identified, with
  assurance that the identity is not false
• Technology
• User Id/Password
• Digital certificates

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Integrity

• Protects against modification
• Ensures that only authorized parties are able to
  modify an electronic document or
• Allow modification to be detected
• Technology
• Digital signatures

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Non-repudiation

• Protects against an e-commerce participant acting
  in bad faith
• Require that neither the sender nor the receiver
  of a message be able to deny the transmission
• Technology
• (Complicated)

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Access control

• Protects against unauthorized access
• Allows the establishment of fine-grained control
  over access to files and applications for
  different users and groups
• Technology
• (Various, usually tied to authentication)

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Availability

• Protects against interruption
• Requires that computer system asset be available
  to authorized parties when needed
• Technology
• (Many)

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The big picture

• Security is a multi-faceted feature of
  information systems
• An organization needs
• A security strategy tailored for its particular
  needs
• A security architecture that addresses that
  strategy
• Security technology to realize the architecture

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Security strategy

• Threats
• what is valuable?
• who might want it?
• Vulnerabilities
• where is the organization exposed?
• Defenses
• what can be done to manage the risks?
• Legal
• what liabilities and legal requirements exist?

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Security architecture

• People
• how are they hired, trained, monitored, audited?
• Systems
• what systems exist?
• how are systems connected to each and to the
  larger Internet?
• Procedures
• how are systems used?
• who gets access to what under what circumstances?

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Security technology

• Main focus of this course
• Specific technologies for achieving
  security-related goals
• But
• meaningless in the absence of a strategy and an
  architecture

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Assignment 1

• Create a web page for your assignments
• I will link these to the course page
• Subscribe to CERT Advisory mailing list
• Post on the "Test" forum
• Due before class starts
• No late assignments!

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Next week

• Cryptography
• Reading
• Ford Baum, Ch. 4
• Risks Digest
• Should be prepared for discussion