big encryption on a small budget

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Big Encryption on a Small Budget

Beth E. BindeHarold W. Winshel


EDUCAUSE Security Professionals Conference

Agenda

• Definition of encryption• Need for encryption • Drawbacks to encryption • Criteria for product selection • Encryption demonstration



What is encryption?

• Coding a message to conceal meaning

• Reduces impact of eavesdropping

• Helps protect Data At Rest



How it works: Digital Substitution Example • Apply the encryption key: 1010011 1010010

1001110• To the plain text message CAT: 1000011 1000001

1010100• XOR operation

– 0 if the same – 1 if different

• The elements of the key correspond to letters: – 1010011 = S – 1010010 = R – 1001110 = N



Result

1000011 1000001 1010100⊕ 1010011 1010010 1001110 ====== ====== ======= 0010000 0010011 0011010 ← Cipher text

• These binary strings correspond to ASCII control characters. They aren’t even printable!

• Results of string lookup: – Data Link Escape → 0010000– Device Control 3 → 0010011– Substitute → 0011010



Recover original message

• Ciphertext: 0010000 0010011 0011010 • Key: 1010011 1010010 1001110 • Apply XOR operation • Original: 1000011 1000001 1010100



Caution!

• Don’t trust a secret or proprietary algorithm or roll your own– Public scrutiny by multiple experts finds the flaws– Public scrutiny beneficial

• Protect keys – Keys essential for decryption– Even knowing the algorithm is not sufficient

• Don’t rely on any single technology or measure for security



Why encrypt?

• Protect confidential data – Non-public personal information (NPPI) – Intellectual property

• Regulatory requirements



Data Breach Incidents

• A Chronology of Breaches http://www.privacyrights.org/ar/ChronDataBreaches.htm

• Educational Security Incidents http://www.adamdodge.com/esi



RegulationDate of

EnforcementFine Imprisonment Industry

HIPAA 1996 $250,000 10 years Health

GLBA 1999 $100,000 per incident 5 years Financial

PCI 2005 $500k per incident + $100k if VISA is not notified

None—Rescind the right to accept credit card payments

Credit Card Security

Sanctions for Regulatory Non-Compliance



Summary



Big Thefts of Notebooks with Sensitive Data.• 28,600,000 records of American military veterans

discharged since 1975 (SSN’s, names, dates of birth, etc.) on a laptop computer stolen from a VA’s ee’s home on May 22, 2006.

• 60,000 current and former employees of Starbucks on four Starbucks laptop computers that were lost. Contained employee’s names, addresses and SSN’s (Nov 3, 2006).

• 48,000 records of American military veterans that might contain SSN’s on a portable hard drive stolen or missing, from VA Medical Center in Birmingham, AL (Feb 2, 2007).



Reportable Incident?

“… notification is required if there is reasonable belief that data were acquired by an unauthorized individual.” (Steve Schuster / Tracy Mitrano, Cornell)

Is the information is in the physical possession and control of an unauthorized person, such as a lost or stolen computer or other device containing unencrypted notice-triggering information? (Cal State Northridge).



If Encryption’s So Great, How Come Everyone Doesn’t Use It?

• Cost of purchase• Time

– Product evaluation and testing – Installation and maintenance – Staff training – User education

• Loss of data due to corruption of encrypted disks • Possible lock out due to forgotten passwords



Encryption vs. Data Breach

Pay now

… or pay later



Three states of data

Data at rest Data in transit Data in process



Terminology – Authentication Factors

• The more factors the better• One-factor authentication• Two-factor authentication• Three-factor authentication



Our Criteria for Evaluating Encryption Products

• Purchase cost of the product• Size of current user base • Open source?• Availability of support



More Criteria…

• Ease of administration for IT staff• Ease of use for end users• What happens when things go wrong.• Ability to support two-factor authentication.



And more criteria…

• Full disk encryption vs. file / folder encryption.• Keyserver vs. standalone products.• Support of portable media (flash drives, zip drives,

CD’s, etc.)• Not linked to hardware of a specific manufacturer



Why we chose Truecrypt

• Large user base• Great support• Very well received / good reviews • Free



Why we chose Truecrypt…more…

• File / folder• Supports two factor authentication.• Supports multiple operating systems.• Encrypts portable media.



Truecrypt Details.

• Truecrypt volumes:– File-hosted volumes (aka Container volume)– Device hosted volumes (partition).

• Truecrypt won’t encrypt existing files.– Encrypting an existing file will overwrite that file.

• Password is entered once to decrypt a volume.• Truecrypt never saves decrypted data to a disk.

– Decrypted data temporarily stored in ram.– Even when volume is mounted, data on disk still encrypted.– Password is entered once to decrypt a volume.

• Travelor mode.• Date / time stamp of the file.



Steps in Creating / Using a Truecrypt Encrypted Area:• Create a Truecrypt volume.• Mount a Truecrypt volume.• Copy files to / from a Truecrypt volume.• Dismount a Truecrypt volume.



Things We Don’t Favor About Truecrypt

• File / folder• Interface a little clunky.• Windows recognition of the Truecrypt volume when it

is not mounted.



Current TrueCrypt Vulnerability

• Escalation of privileges by local users • Applies to Linux implementation • Reported March 28, 2007 • Must be running TrueCrypt as setuid root • Exploit available • More information here:

http://www.securityfocus.com/bid/23180/info



Features of Other Encryption Products We Reviewed.

• Which features were typical to many products• Which features were considered positive • Which features where considered negative



Some Other Encryption Products We Looked At.• Encryption utilities on flash drives.• Axcrypt• Cryptainer• SafeEnd• Windows EFS• Windows Vista Bitlocker• Pointsec• Safeboot• Authenix• PGP



Suggestions / Policies

• Get senior administration support for policies to protect data

• Don’t store sensitive data if you don’t have to• Use utilities to find files with sensitive data• Require encryption for sensitive data



Conclusion

• What is encryption?• Why do you need it?• Encryption as part of an overall security posture• Sharing experiences to help you



Truecrypt available at:

www.truecrypt.org

big encryption on a small budget

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