Toward Sensitive Information Redaction
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Transcript of Toward Sensitive Information Redaction
Computer Science / www.isec.utulsa.edu
Toward Sensitive Information Redaction in a Collaborative,
Multilevel Security Environment
Peter Gehres, Nathan Singleton, George Louthan, John Hale
WikiSym 2010, Gdansk, Poland, July 8, 2010
Computer Science / www.isec.utulsa.edu
Overview • Background • Related Work • Motivation • SecureWiki • Challenges • Potential Environments • Acknowledgments
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Background • Multilevel Security (MLS)
– Traditional military security model – Each object is described by
• Sensitivity level (unclassified, confidential, secret, top secret) • Compartments (e.g nuclear, europe, missle defense)
• Bell-La Padula – Based on the MLS model – Read Down – Write Up
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Background, cont. • Text Redaction
– Tradtional redaction • Black out using a marker • Cut out using scissors
– Digital techniques • Remove the underlying data • Challenges:
– Metadata – Incomplete redaction
An example of traditional redaction
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Related Work • Intellipedia
– Based on MediaWiki – Three distinct wikis for unclassified, confidential and secret on
separate physical networks – Problem: Many places to go for information on a single subject
Computer Science / www.isec.utulsa.edu
Related Work • Tearline Wiki
– Aggregates multiple wikis with "tear lines" between the classifications
– Problems • Information is still segregated • Still in testing at the NSA • Proprietary technology
From Galois Brief, “Tearline Wiki: Information collaboration across security domains”
Computer Science / www.isec.utulsa.edu
Motivations
• To promote information sharing in sensitive environments – Government – Healthcare – Corporate Intellectual Property
• To combine all information about a subject into a single, consolidated view by increasing granularity
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SecureWiki - Architecture • Store all article markup in separate data store
• Generate keys to indicate redacted text in markup
• Store keys in key store and generate tokens used to replace markup in page (mapped to a key by the key store)
• Replace tokens with markup during render of page (after checking authentication)
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SecureWiki
Architecture Diagram
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SecureWiki - Example
Excerpt from http://en.wikipedia.org/wiki/KFC
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Initial Page Request
SECRET
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Initial Page Request
SECRET
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The “Unclassified” Recipe
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Wiki Markup
[snip]
In 1983, writer [[William Poundstone]] examined the recipe in his book ''[[Big Secrets]]''. He
reviewed Sanders' [[patent]] application, and advertised in college newspapers for present or
former employees willing to share their knowledge. From the former he deduced that Sanders had
diverged from other common fried-chicken recipes by varying the amount of oil used with the
amount of chicken being cooked, and starting the cooking at a higher temperature (about
{{convert|400|F|-1}}) for the first minute or so and then lowering it to {{convert|250|F|-1}} for the
remainder of the cooking time. {\redact 123} Following his buyout in 1964, Colonel Sanders
himself expressed anger at such changes, saying:
[snip]
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SecureWiki - Example
SECRET
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SecureWiki - Example
SECRET
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SecureWiki - Example
SECRET
abc
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The “Confidential” Recipe
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Wiki Markup [snip]
{\redact 456}
On February 9, 2009, the secret recipe returned to KFC's Louisville headquarters in a more secure, computerized
vault.
In 1983, writer [[William Poundstone]] examined the recipe in his book ''[[Big Secrets]]''. He reviewed
Sanders' [[patent]] application, and advertised in college newspapers for present or former employees willing to
share their knowledge. From the former he deduced that Sanders had diverged from other common fried-chicken
recipes by varying the amount of oil used with the amount of chicken being cooked, and starting the cooking at a
higher temperature (about {{convert|400|F|-1}}) for the first minute or so and then lowering it to {{convert|250|F|-1}}
for the remainder of the cooking time. Several of Poundstone's contacts also provided samples of the seasoning
mix, and a food lab found that it consisted solely of [[sugar]], [[flour]], [[salt]], [[black pepper]] and [[monosodium
glutamate]] (MSG). He concluded that it was entirely possible that, in the years since Sanders sold the chain, later
owners had begun skimping on the recipe to save costs
[snip]
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SecureWiki - Example
SECRET
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SecureWiki - Example
SECRET
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SecureWiki - Example
SECRET
def
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Wiki Markup [snip]
Before the move, KFC disclosed the following details about the recipe and its security arrangements:
* The recipe, which includes exact amounts of each component, is written in pencil on a single sheet of notebook
paper and signed by Sanders.
* The recipe was locked in a filing cabinet with two separate combination locks. The cabinet also included vials of
each of the {\redact 789} herbs and spices used.
* Only two executives had access to the recipe at any one time. KFC refuses to disclose the names and titles of
either executive
* One of the two executives said that no one had come close to guessing the contents of the secret recipe, and
added that the actual recipe would include some surprises.
On February 9, 2009, the secret recipe returned to KFC's Louisville headquarters in a more secure, computerized
vault.
[snip]
[snip]
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SecureWiki - Example
SECRET
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SecureWiki - Example
SECRET
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SecureWiki - Example
SECRET
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Final Output – “Secret” Recipe
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Challenges • Metadata
– A page’s existence may be classified – Data inference
• Verification of security controls – Certification and accreditation
• Declassifying Information – Bell-La Padula prohibits write-down
• Implementation – Hooks into parser – Saving data – Revision History?
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Potential Environments • Military and government
• Medical research – Collaboration in blind/double-blind studies – Compliance with HIPPA PII/PHI requirements
• Corporations – Chinese Wall implementation – Inter-departmental segregation – Inter-corporation collaboration
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Conclusions • Redaction in wikis is possible with high granularity for
secure environments.
• SecureWiki integrates the information into a single view based on the user's access level.
• SecureWiki has potential not only in government but also corporate, healthcare and other environments.
Computer Science / www.isec.utulsa.edu
Future Work • Develop a proof of concept
– Determine the real challenges in implementation – Expand the workflow of the system
• Determine the wiki framework (MediaWiki?) – Ability to add our framework without modifying (too much)
core code – Access controls – Known vulnerabilities
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Acknowledgements • Mr. Philippe Beaudette, Head of Reader Relations,
Wikimedia Foundation
• Dr. Rose Gamble, Professor, The University of Tulsa
• This material is based on research sponsored by DARPA under agreement number FA8750-09-1-0208. The U.S. Government is authorized to reproduce and distribute reprints for Governmental purposes notwithstanding any copyright notation thereon. The views and conclusions contained herein are those of the authors and should not be interpreted as necessarily representing the official policies or endorsements, either expressed or implied, of DARPA or the U.S. Government.
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Questions?