Chapter 7

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Transcript Chapter 7 

Chapter 7
Multilevel Security
What can everyone learn from military
and government application security
Military
Huge amount of money spent on
research for Computer Science
 Products developed will find themselves
in commercial applications
 Commercial systems use multilevel
security
 Multilevel systems also applied where
not necessary or required
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Security Policy
What it a Security Policy
 Who determines need-to-know and how
 How is it enforced what are the
consequences
 How do we detect breaches
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Bell-LaPadula Security Policy Model (BLP)
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Classifications and Clearances
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Rules and controls built around these clearances
including software
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Known as MultiLevel Security (MLS)
 Basic property is information can not flow
downward.
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No Read Up (NRU)
No Write Down (NWD)
High Water Mark
 Role based access Control (RBAC)
Biba Model
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Confidentiality integrity are dual concepts
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Often need to protect integrity with no concern
for confidentiality
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Confidentiality who can read
Integrity who can write
Read up
Write down
Used to build many systems
 Often called using low-water mark
 LOMAC Linux extension uses it
MultiLevel security systems
Secure communications Processor
SCOMP 1983 DOD sponsored
 MLS Unix
 NRL Pump
 Logistics information
 Purple Penelope
 Future
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What goes wrong
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Composability
Cascade problem
Covert channels
Threat from virus
Polyinstantiation
MLS systems very costly
Application software needs to re-written to run
on MLS system
Others issues pointed out pages 156-157
Broader implications of MLS
MLS and it’s development and funding
has spun off a lot of useful ideas
 The biggest hole in secure systems
remain people
 Government and it’s levels of
bureaucracy and secrecy will remain an
issue for any system
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Discussion
What are some current security models
and how are they being used
 LOMAC and Linux
 MLS based firewalls
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Discussion articles
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http://www.cisilion.com/netforensics.htm
http://www.sans.org/rr/whitepapers/tools/408.php
- Firewalls, by "area"
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- ecommerce
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- inside out
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- partners
 - Intrusion detection
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- 40,000 day one
 - Forensic server product
 - All outside web content cached
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- check for malware before caching
 - Level 7 switches for load balancing web traffic
Discussion articles
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Google Chinese site:
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IPv6
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Interesting way to rebel against censorship…
http://www.eweek.com/article2/0,1895,1917739,00.asp
Current situation and stance: http://www.progressiveu.org/161618-googlechina-vs-google-usa
http://www.ipv6.ru/docs/ebsco/fulltext14.htm Privacy issues of IPv6
http://www.internetnews.com/infra/article.php/3570211 -- Cost of IPv6
http://www.larta.org/lavox/articlelinks/2004/041129_ipv6.asp -- Older article
but great reasons to adopt IPv6.
http://www.tcpipguide.com/free/t_IPv6InterfaceIdentifiersandPhysicalAddress
Mapping.htm IPv6 addressing scheme
Threat modeling
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http://www.theserverside.net/news/thread.tss?thread_id=33973
http://blogs.msdn.com/ptorr/archive/2005/02/22/GuerillaThreatModelling.aspx
List of Resources
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Bell-LaPadula
 http://en.wikipedia.org/wiki/BellLaPadula_model
 http://www.cs.unc.edu/~dewan/242/f96/note
s/prot/node13.html
 http://courses.cs.vt.edu/~cs5204/fall99/prote
ction/harsh/
List of Resources
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Multi Level Security
http://en.wikipedia.org/wiki/Multilevel_security
 http://www.cs.stthomas.edu/faculty/resmith/r
/mls/index.html
 http://nsi.org/Library/Compsec/sec0.html
 http://www.smat.us/crypto/mls/index.html
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List of Resources
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Role Based Access Control
http://csrc.nist.gov/rbac/NIST-ITL-RBACbulletin.html
 http://csrc.nist.gov/rbac/
 http://en.wikipedia.org/wiki/RBAC
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List of Resources
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Biba model
http://en.wikipedia.org/wiki/Biba_model
 http://en.wikipedia.org/wiki/Biba_Integrity_M
odel
 http://www.answers.com/topic/biba-integritymodel
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List of Resources
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LOMAC
http://linas.org/mirrors/opensource.nailabs.c
om/2002.02.28/lomac/
 http://alum.wpi.edu/~tfraser/Software/LOMA
C/index.html
 http://freshmeat.net/projects/lomac
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List of Resources
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SCOMP
http://users.tkk.fi/~lhuovine/study/secbas98/
skernel.html
 http://www.stsc.hill.af.mil/crosstalk/2005/08/
0508Vanfleet_etal.html
 http://www.windowsecurity.com/whitepaper/
NCSCTG007_Burgundy_book_.html
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List of Resources
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MLS Unix
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http://www.cs.dartmouth.edu/~doug/IX/
http://citeseer.ist.psu.edu/mcilroy92multilevel.html
NRL pump/Purple Penelope
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http://www.networkpenetration.com/adv_steg_posix
_flock.html
http://www.securityprotocols.com/modules.php?name=News&file=print
&sid=1360