Transcript Security and Privacy - UNC Computer Science

Presentation Basics
Speak loudly and clearly
 Give the audience something to look at
 Show interest even when not speaking
 Show passion

This is passion.
This is passion.
This is passion.
This is not.
Demo Basics
Script your demos
 Avoid a lot of typing
 Avoid silences
 Use the “turkey in the oven”

Security and Privacy
Security: the protection of data,
networks and computing power
 Privacy: complying with a person's
desires when it comes to handling his or
her personal information

When you walk into the store, the
big-screen displays "Hello Tom,"
your shopping habits, and other
information
from Minority Report
Some Views on Privacy

“All this secrecy is making life harder, more
expensive, dangerous …”
Peter Cochran, former head of BT (British Telecom)
Research

“You have zero privacy anyway.”
Scott McNealy, CEO Sun Microsystems

“By 2010, privacy will become a
meaningless concept in western society”
Gartner report, 2000
Legal Realities of Privacy
Self-regulation approach in US, Japan
 Comprehensive laws in Europe,
Canada, Australia
 European Union

 Limits data collection
 Requires comprehensive disclosures
 Prohibits data export to unsafe countries
○ Or any country for some types of data
Aspects of Privacy
Anonymity
 Security
 Transparency and Control: knowing
what is being collected

Privacy and Trust
Right of individuals to determine if, when,
how, and to what extent data about
themselves will be collected, stored,
transmitted, used, and shared with others
 Includes

 right to browse the Internet or use applications
without being tracked unless permission is
granted in advanced
 right to be left alone
True privacy implies invisibility
 Without invisibility, we require trust

Privacy Aware Technologies
 non-privacy-related
solutions that
enable users to protect their
privacy
 Examples
 password and file-access security
programs
 unsubscribe
 encryption
 access control
Privacy Enhancing Technologies
 Solutions
that help consumers
and companies protect their
privacy, identity, data and actions
 Examples
 popup blockers
 anonymizers
 Internet history clearing tools
 anti-spyware software
Impediments to Privacy
Surveillance
 Data collection and sharing
 Cookies – how long are they retained?
 Sniffing, Snarfing, Snorting

 All are forms of capturing packets as they pass
through the network
 Differ by how much information is captured and
what is done with it
P3P (2002)

Platform for Privacy Preference (P3P)
 World Wide Web Consortium (W3C) project
Voluntary standard
 Structures a web site’s policies in a
machine readable format

 Allows browsers to understand the policy
and behave according to a user’s defined
preferences

Short-lived: why?
Do Not Track
Opt
out technology
 HTTP header
 2012 pledge not honored
Privacy and Wireless

“Wardriver” program: scans for broadcast
SSIDs
 broadcasting improves network access, but at a cost

once the program finds the SSID
 obtains the IP address
 obtains the MAC address
 …

Lowe’s was penetrated this way
 Stole credit card numbers
Deep Web
Anything that can’t be indexed (estimate
97%!)
 Accessible through secure browsers: Tor

 Anonymity
 Difficulty in tracing
 Onion addresses of interest
Consider
1994: Vladimir Levin breaks into Citibank's
network and transfers $10 million dollars
into his accounts
 Mid 90’s: Phonemasters

 stole tens of thousands of phone card numbers
 found private White House telephone lines

1996: Tim Lloyd, disgruntled employee
inserts time bomb that destroys all copies
of Omega Engineering machining code.
Estimated lost: $10 million.
Security “Gospel”
The Morris Internet worm of 1988 cost $98
million to clean up
 The Melissa virus crashed email networks
at 300 of the Fortune 500 companies
 The Chernobyl virus destroyed up to a
million PCs throughout Asia
 The ExploreZip virus alone cost $7.6 billion
to clean up

Security Reality




The Morris Internet worm of 1988 cost $98
under $1 million to clean up
The Melissa virus crashed scared executives
into disconnecting email networks at 300 of
the Fortune 500 companies
The Chernobyl virus destroyed caused
replacement of up to a million PCs throughout
Asia
The ExploreZip virus alone could have cost
$7.6 billion to clean up
Information Systems Security

Deals with
 Security of (end) systems
○ Operating system, files, databases,
accounting information, logs, ...
 Security of information in transit over
a network
○ e-commerce transactions, online
banking, confidential e-mails, file
transfers,...
Basic Components of Security

Confidentiality
 Keeping data and resources secret or hidden

Integrity
 Ensuring authorized modifications
 Refers to both data and origin integrity

Availability
 Ensuring authorized access to data and resources when
desired

Accountability
 Ensuring that an entity’s action is traceable uniquely to
that entity

Security assurance
 Assurance that all four objectives are met
Info Security 20 Years Ago

Physical security
 Information was primarily on paper
 Lock and key
 Safe transmission

Administrative security
 Control access to materials
 Personnel screening
 Auditing
Information Security Today


Increasing system complexity
Digital information security importance
 Competitive advantage
 Protection of assets
 Liability and responsibility

Financial losses
 FBI estimates that an insider attack results in an average loss of $2.8
million
 Estimates of annual losses: $5 billion - $45 billion (Why such a big
range?)

Protection of critical infrastructures
 Power grid
 Air transportation

Government agencies
 GAO report (03): “severe concerns” security mgmt & access control
 Grade F for most of the agencies
 Limkages accerbate
Attack Vs Threat

A threat is a “potential” violation of
security
 Violation need not actually occur
 Fact that the violation might occur makes it a
threat

The actual violation (or attempted
violation) of security is called an attack
Common security attacks

Interruption, delay, denial of receipt or denial of service
 System assets or information become unavailable or are rendered
unavailable

Interception or snooping
 Unauthorized party gains access to information by browsing through
files or reading communications

Modification or alteration
 Unauthorized party changes information in transit or information stored
for subsequent access

Fabrication, masquerade, or spoofing
 Spurious information is inserted into the system or network by making
it appear as if it is from a legitimate source

Repudiation of origin
 False denial that the source created something
Denial of Service Attacks

explicit attempt to prevent legitimate users from
using service
two types of attacks

asymmetric attack

 denial of service (DOS)
 distributed denial of service (DDOS)
 attacker with limited resource (old PC and slow modem) may
be able to disable much faster and more sophisticated
machines or networks

methods
 Bots or Zombie machines
 Trojans or Smurf attack: distributed attack that sends
specified number of data packets to a victim
Phishing (Spoofing)





use 'spoofed' e-mails and fraudulent websites
designed to fool recipients into divulging personal
financial data
 credit card numbers
 account usernames and passwords
 social security numbers
hijacking of trusted brands
 banks
 online retailers
 credit card companies
able to convince up to 5% of recipients to respond
http://www.antiphishing.org/
Goals of Security

Prevention
 Prevent someone from violating a security policy

Detection
 Detect activities in violation of a security policy
 Verify the efficacy of the prevention mechanism

Recovery





Stop attacks
Assess and repair damage
Ensure availability in presence of ongoing attack
Fix vulnerabilities to prevent future attacks
Deal with the attacker
Human Issues

Outsiders and insiders
 Which is the real threat?

Social engineering
 How much should a company disclose about
security?
 Claim more or less security than exists
Honeypots
 Setting
up a server to attract hackers
 Used by corporations as early warning
system
 Used to attract spam to improve filters
 Used to attract viruses to improve detection
 http://www.honeypots.net/
Security Level of Encrypted Data

Unconditionally Secure
 Unlimited resources + unlimited time
 Still the plaintext CANNOT be recovered
from the ciphertext

Computationally Secure
 Cost of breaking a ciphertext exceeds the
value of the hidden information
 The time taken to break the ciphertext
exceeds the useful lifetime of the information
Types of Attacks

Ciphertext only
 adversary has only ciphertext
 goal is to find plaintext, possibly key

Known plaintext
 adversary has plaintext and ciphertext
 goal is to find key

Chosen plaintext
 adversary can get a specific plaintext
enciphered
 goal is to find key
Attack Mechanisms
Brute force
 Statistical analysis

 Knowledge of natural language
 Examples:
○ All English words have vowels
○ There are only 2 1-letter words in English
○ High probability that u follows q
○…
Caesar Cipher
Substitute the letter 3 ahead for each
one
 Example:

 Et tu, Brute
 Hw wx, Euxwh

Quite sufficient for its time
 High illiteracy
 New idea
Enigma Machine
(Germany, World War II)
Simple Caesar
cipher through each
rotor
 But rotors shifted at
different rates

 Roller 1 rotated one
position after every
encryption
 Roller 2 rotated
every 26 times…
Private Key Cryptography

Sender, receiver share common key
 Keys may be the same, or trivial to derive from
one another
 Sometimes called symmetric cryptography or
classical cryptography

Two basic types
 Transposition ciphers (rearrange bits)
 Substitution ciphers

Product ciphers
 Combinations of the two basic types
DES (Data Encryption Standard)

A block cipher:
 encrypts blocks of 64 bits using a 64 bit key
 outputs 64 bits of ciphertext
 A product cipher
○ performs both transposition (permutation) and
substitution on the bits

Considered weak
 Susceptible to brute force attack
Cracking DES
1998: Electronic Frontier Foundation
cracked DES in 56 hrs using a
supercomputer
 1999: Distributed.net cracked DES in 22
hrs
 With specialized hardware, DES can be
cracked in less than an hour.

History of DES

IBM develops Lucifer for banking systems (1970’s )
NIST and NSA evaluate and modify Lucifer

(1974)
Modified Lucifer adopted as federal standard (1976)
 Name changed to Data Encryption Standard (DES)
 Defined in FIPS (46-3) and ANSI standard X9.32

NIST defines Triple DES (3DES) (1999)
 Single DES use deprecated - only legacy systems.

NIST approves Advanced Encryption Std. (AES) (2001)
 AES (128-bit block)
 Attack published in 2009

Current state of the art is AES-256
Public Key Cryptography

Two keys
 Private key known only to individual
 Public key available to anyone
○ Public key, private key inverses

Confidentiality
 encipher using public key
 decipher using private key

Integrity/authentication
 encipher using private key
 decipher using public one
Public Key Requirements
1.
2.
3.
Computationally easy to encipher or
decipher a message given the
appropriate key
Computationally infeasible to derive the
private key from the public key
Computationally infeasible to determine
the private key using a chosen plaintext
attack
RSA





Public key algorithm described in 1977 by
Rivest, Shamir, and Adelman
Exponentiation cipher
Relies on the difficulty of factoring a large
integer
RSA Labs now owned by EMC
A Guide to RSA
Summary

Private key (classical) cryptosystems
 encipher and decipher using the same key

Public key cryptosystems
 encipher and decipher using different keys
 computationally infeasible to derive one from
the other

Both depend on keeping keys secret
 Depend on computational difficulty
 As computers get faster, …
Photon Cryptography
Use photons for key distribution
 Prevents eavesdropping: reading a
photon changes its state

Authentication

Assurance of the identity of the party
that you’re talking to

Primary technologies
 Digital Signature
 Kerberos
“Using encryption on the Internet is the
equivalent of arranging an armored car to
deliver credit card information from someone
living in a cardboard box to someone living on
a park bench”
– Gene Spafford (Purdue)
Firewall Techniques

Filtering
 Doesn’t allow unauthorized messages through
 Can be used for both sending and receiving
 Most common method

Proxy
 The firewall actually sends and receives the
information
 Sets up separate sessions and controls what
passes in the secure part of the network
DMZ: Demilitarized Zone

Arrangement of firewalls to form a buffer
or transition environment between
networks with different trust levels
Internet
Fire
wall
Fire
wall
Internal
resources
Three Tier DMZ
Internet
Fire
wall
Fire
wall
Web
Server
Fire
wall
App
Server
Internal
resources