7 lecture 340 online tracking encryption
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Online TrackingEncryption
Janine L. Spears, Ph.D.
May 8, 2012
DePaul University
CNS 340
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1. Announcements
2. Online tracking and data re-identification
3. Encryption
a) Whole disk
b) Database
c) Key managementd) Example of tools
e) Public vs. private encryption algorithms
This Evenings Agenda
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HW 3 due today1. John the Ripper
2. Recuva
3. Eraser
4. Secunia
HW 4 (Policy) is due next Tues, May 15th by 5:45pm CST
Announcements
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Reading assignment: To Track or Do Not Track byTene and Polonetsky, Aug 2011
Read pages 1-14
Article is posted in Week 7 folder on D2L
This article will be helpful for:1. Extra credit assignment
2. Quiz #3
3. Group project
The browser security assignment that was listed in thecourse schedule will be a group assignment
There is one remaining individual assignment (HW 5) that willbe assigned next week
Announcements
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Group assignment posted this week:
Due Mon, Jun 4th, 11:59pm (night b4 Final Exam meeting)
Group presentations will be in place of a final exam
Form groups either:
a) In person (on-campus section)
b) Via CATME survey (online and on-campus sections; an email will besent from CATME)
Announcements
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Extra credit assignment will be emailed later this week
Quiz #2 review.
Announcements
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Personally Identifiable Information (PII) Identified data
Identifiable data
Non-PII, but when aggregated or combined with
other data could lead to the identification of anindividual
In other words, Non-PII can be transformed into PII
Identified vs. Identifiable Data
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De-identification of data occurs when personallyidentifiable information is stripped from a dataset in
order to make the data anonymous
Re-identification = linking de-identified data to identifieddata
Re-identification of data occurs when a third party joinsanonymized data with a small amount of auxiliary data
from another database and de-anonymizes the data (Porter2008)
Data Re-Identification
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Re-identification may occur through data aggregation
Aggregation refers to the combination of various types of data
Data Aggregation
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Example of Data Re-Identification
Anonymous data set:
Name: Unique alpha-numericalidentifier
Age: 13
Favorite Toy: Legos
Favorite Movie: Batman
Favorite Candy: Snickers
Favorite Restaurant: McDonalds
Zip Code: 20052
Facebook data set:
Name: Billy Doe
Age: 13Location: I live in Washington, DC
Narrative: I love to build things with Legos. I
love Snickers bars. I recently saw the
Batman movie and thought it was the coolest
movie ever!
Another data set:
Name: William Doe
Date of Birth: 04-04-1996
Address: 2000 H Street, NW, Washington, DC 20052
Schwartz & Solove, NY University Law Review 2011
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According to an academic study, a combination of the
following info is sufficient to identify 87%
of the population:
1. Birth date
2. Zip code
3. Gender
Re-Identification using Simple Demographic Data (1 of 3)
Data typically considered non-PII Generally not considered
embarrassing or sensitive
Available via census data
Latanya Sweeney (2000)
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In the 1970s, the US Census Bureau began sellingcensus data
The data only contained addresses, not names
How were marketing companies able to identify
individuals?
1. Telephone lists
2. Voter registration lists
Re-Identification using Simple Demographic Data (2 of 3)
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Predicting social security numbers
http://www.youtube.com/watch?v=sqjTyN8-q2w
http://www.cnn.com/2009/US/07/10/social.security.number
s/index.html?iref=allsearch
Study was conducted by Alessandro Acquisti and Ralph
Gross
http://www.heinz.cmu.edu/news/news-
detail/index.aspx?nid=991
Re-Identification using Simple Demographic Data (3 of 3)
http://www.youtube.com/watch?v=sqjTyN8-q2whttp://www.cnn.com/2009/US/07/10/social.security.numbers/index.html?iref=allsearchhttp://www.cnn.com/2009/US/07/10/social.security.numbers/index.html?iref=allsearchhttp://www.heinz.cmu.edu/news/news-detail/index.aspx?nid=991http://www.heinz.cmu.edu/news/news-detail/index.aspx?nid=991http://www.heinz.cmu.edu/news/news-detail/index.aspx?nid=991http://www.heinz.cmu.edu/news/news-detail/index.aspx?nid=991http://www.heinz.cmu.edu/news/news-detail/index.aspx?nid=991http://www.cnn.com/2009/US/07/10/social.security.numbers/index.html?iref=allsearchhttp://www.cnn.com/2009/US/07/10/social.security.numbers/index.html?iref=allsearchhttp://www.youtube.com/watch?v=sqjTyN8-q2whttp://www.youtube.com/watch?v=sqjTyN8-q2whttp://www.youtube.com/watch?v=sqjTyN8-q2w -
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Data aggregation and data re-identification
Are not within scope of existing US privacy laws
Are a privacy concern with regard to onlinebehavioral tracking (targeted advertising)
Data Aggregation
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The anonymity myth refers to the incorrectassumption that a person remains anonymous (i.e., is
not identifiable) while on the web, as long as he/she
does not use his/her name
The anonymity myth stems from a mistaken conflation
between momentary anonymity and actual
untraceability
Anonymity Myth (1 of 2)
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What is the key piece of information that enables
traceability of ones actions once connected to theinternet?
The IP address is a unique identifier that is assigned to
every computer connected to the Internet.
Due to the shiftfrom dynamic IP addresses for dial-up
connections to static IP addresses for broadband
connections, ISPs now have logs (that could span years)that link IP addresses with particular computers and, in
many cases, eventually to specific users.
Only 5% of Americans still use dial-up (Pew Research Center 2010)
Anonymity Myth (2 of 2)
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Connection to a website requires a browser to provide
the users IP address
Various tools can provide info on an IP address, such as:
Host name
Geographic location
A map
IP Address
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Identify browser tools that reduce the amount of: Browser footprinting
Online tracking
Group Project Assignment
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Two issues are driving a major increase in the useof encryption
What are they?
Data Encryption
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Encryption is the process ofconverting an original
message into a form that is unreadable (aka ciphertext).
Decryption is the process ofconverting the ciphertext
message back into plaintext so that it is readable.
Data Encryption
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Encrypting data at rest:
a) Whole disk encryption
Hard drive encryption
USB drive encryption
b) Folder/file encryption
c) Database encryption
Data Encryption
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How Whole Disk Encryption works:
http://www.symantec.com/content/en/us/enterprise/white
_papers/b-
pgp_how_wholedisk_encryption_works_WP_21158817.en-
us.pdf
Whole Disk Encryption (1 of 5)
http://www.symantec.com/content/en/us/enterprise/white_papers/b-pgp_how_wholedisk_encryption_works_WP_21158817.en-us.pdfhttp://www.symantec.com/content/en/us/enterprise/white_papers/b-pgp_how_wholedisk_encryption_works_WP_21158817.en-us.pdfhttp://www.symantec.com/content/en/us/enterprise/white_papers/b-pgp_how_wholedisk_encryption_works_WP_21158817.en-us.pdfhttp://www.symantec.com/content/en/us/enterprise/white_papers/b-pgp_how_wholedisk_encryption_works_WP_21158817.en-us.pdfhttp://www.symantec.com/content/en/us/enterprise/white_papers/b-pgp_how_wholedisk_encryption_works_WP_21158817.en-us.pdfhttp://www.symantec.com/content/en/us/enterprise/white_papers/b-pgp_how_wholedisk_encryption_works_WP_21158817.en-us.pdfhttp://www.symantec.com/content/en/us/enterprise/white_papers/b-pgp_how_wholedisk_encryption_works_WP_21158817.en-us.pdfhttp://www.symantec.com/content/en/us/enterprise/white_papers/b-pgp_how_wholedisk_encryption_works_WP_21158817.en-us.pdfhttp://www.symantec.com/content/en/us/enterprise/white_papers/b-pgp_how_wholedisk_encryption_works_WP_21158817.en-us.pdfhttp://www.symantec.com/content/en/us/enterprise/white_papers/b-pgp_how_wholedisk_encryption_works_WP_21158817.en-us.pdf -
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What gets encrypted:
Encrypts the entire disk including system files,
temporary files, etc.
Whole disk encryption automatically encryptseverything the user or O/S creates
Encryption/decryption is transparent to user
Benefit: If encrypted disk is lost, stolen, or placedinto another computer, drive remains encrypted
Whole Disk Encryption (2 of 5)
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When is data encrypted:
Works in conjunction with the O/S file system
Data is encrypted blocks at a time first time
When a user accesses a file, the data is decrypted
in memory
If user makes changes to a file, the data is
encrypted in memory and written back to drive
Decrypted data is never availableon the disk
Whole Disk Encryption (3 of 5)
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Limitation of whole disk encryption:
Once user logs into the system during startup, filescan be opened by anyone
If user has logged in and leaves computerunattended (e.g., in a coffee shop), anunauthorized user can access data
Whole Disk Encryption (4 of 5)
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Recovery methods:
1. Local self-recovery (users customizable pre-definedquestions)
2. Recovery Token (one-time use)
3. Administrator key stored on a token or smart card
Best practices: before encrypting whole disk,
1. Create a Recovery CD
2. Backup the drive
Whole Disk Encryption (5 of 5)
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If someone reports a lost or stolen PC, what are
some questions that need to be asked?
Was the user logged on to the system?
If so, was user logged on to network?
If so, what data does user have access to?
Company also should define lost and stolen. At what point is a device considered stolen?
Lost or Stolen Laptops with Whole Disk Encryption
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An example of layered security (aka defense-in-depth) for protecting data stored on hard disks:
If data on an encrypted hard disk is vulnerable
after user logs on, what additional layer ofsecurity can be added to encrypt sensitive data on
a hard disk?
Layered Security
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From HW 3:
what is an example of a file encryption tool?
What is an example of an open source
whole disk encryption tool?
Examples of Whole Disk and File Encryption Tools
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3. Checkpoint Full Disk Encryption
http://www.checkpoint.com/products/datasecurity/pc/index.html
4. Pretty Good Privacy (PGP)
Demo for whole disk encryption:http://www.symantec.com/business/products/videos.jsp?pcid=pcat_info_risk_c
omp&pvid=wd_encryption_1
5. TrueCrypt
Free open-source encryption for Windows, Mac, Linux
http://www.truecrypt.org/
6. IronKey
Demo for flash drive encryption (also note key mgmt app):
https://www.ironkey.com/demo-enterprise
Examples of Whole Disk Encryption Tools
http://www.checkpoint.com/products/datasecurity/pc/index.htmlhttp://www.symantec.com/business/products/videos.jsp?pcid=pcat_info_risk_comp&pvid=wd_encryption_1http://www.symantec.com/business/products/videos.jsp?pcid=pcat_info_risk_comp&pvid=wd_encryption_1http://www.truecrypt.org/https://www.ironkey.com/demo-enterprisehttps://www.ironkey.com/demo-enterprisehttps://www.ironkey.com/demo-enterprisehttps://www.ironkey.com/demo-enterprisehttp://www.truecrypt.org/http://www.symantec.com/business/products/videos.jsp?pcid=pcat_info_risk_comp&pvid=wd_encryption_1http://www.symantec.com/business/products/videos.jsp?pcid=pcat_info_risk_comp&pvid=wd_encryption_1http://www.checkpoint.com/products/datasecurity/pc/index.html -
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Using the file or folder encryption feature in
Windows:
Overview of the Encrypting File System (EFS)http://windows.microsoft.com/en-US/windows7/Encrypting-File-System-EFS-recommended-links
Training video on using EFS to encrypt or decrypthttp://windows.microsoft.com/en-us/windows7/Encrypt-or-decrypt-a-folder-or-file
Back up Encrypting File System (EFS) certificate
http://windows.microsoft.com/en-US/windows7/Back-up-Encrypting-File-System-EFS-certificate
SWF Encrypt Encrypt Adobe Flash SWF files:
http://www.amayeta.com/software/swfencrypt/
Examples of File Encryption Tools
http://windows.microsoft.com/en-US/windows7/Encrypting-File-System-EFS-recommended-linkshttp://windows.microsoft.com/en-us/windows7/Encrypt-or-decrypt-a-folder-or-filehttp://windows.microsoft.com/en-US/windows7/Back-up-Encrypting-File-System-EFS-certificatehttp://www.amayeta.com/software/swfencrypt/http://www.amayeta.com/software/swfencrypt/http://windows.microsoft.com/en-US/windows7/Back-up-Encrypting-File-System-EFS-certificatehttp://windows.microsoft.com/en-US/windows7/Back-up-Encrypting-File-System-EFS-certificatehttp://windows.microsoft.com/en-US/windows7/Back-up-Encrypting-File-System-EFS-certificatehttp://windows.microsoft.com/en-US/windows7/Back-up-Encrypting-File-System-EFS-certificatehttp://windows.microsoft.com/en-US/windows7/Back-up-Encrypting-File-System-EFS-certificatehttp://windows.microsoft.com/en-US/windows7/Back-up-Encrypting-File-System-EFS-certificatehttp://windows.microsoft.com/en-US/windows7/Back-up-Encrypting-File-System-EFS-certificatehttp://windows.microsoft.com/en-US/windows7/Back-up-Encrypting-File-System-EFS-certificatehttp://windows.microsoft.com/en-US/windows7/Back-up-Encrypting-File-System-EFS-certificatehttp://windows.microsoft.com/en-US/windows7/Back-up-Encrypting-File-System-EFS-certificatehttp://windows.microsoft.com/en-US/windows7/Back-up-Encrypting-File-System-EFS-certificatehttp://windows.microsoft.com/en-US/windows7/Back-up-Encrypting-File-System-EFS-certificatehttp://windows.microsoft.com/en-US/windows7/Back-up-Encrypting-File-System-EFS-certificatehttp://windows.microsoft.com/en-US/windows7/Back-up-Encrypting-File-System-EFS-certificatehttp://windows.microsoft.com/en-US/windows7/Back-up-Encrypting-File-System-EFS-certificatehttp://windows.microsoft.com/en-us/windows7/Encrypt-or-decrypt-a-folder-or-filehttp://windows.microsoft.com/en-us/windows7/Encrypt-or-decrypt-a-folder-or-filehttp://windows.microsoft.com/en-us/windows7/Encrypt-or-decrypt-a-folder-or-filehttp://windows.microsoft.com/en-us/windows7/Encrypt-or-decrypt-a-folder-or-filehttp://windows.microsoft.com/en-us/windows7/Encrypt-or-decrypt-a-folder-or-filehttp://windows.microsoft.com/en-us/windows7/Encrypt-or-decrypt-a-folder-or-filehttp://windows.microsoft.com/en-us/windows7/Encrypt-or-decrypt-a-folder-or-filehttp://windows.microsoft.com/en-us/windows7/Encrypt-or-decrypt-a-folder-or-filehttp://windows.microsoft.com/en-us/windows7/Encrypt-or-decrypt-a-folder-or-filehttp://windows.microsoft.com/en-us/windows7/Encrypt-or-decrypt-a-folder-or-filehttp://windows.microsoft.com/en-us/windows7/Encrypt-or-decrypt-a-folder-or-filehttp://windows.microsoft.com/en-us/windows7/Encrypt-or-decrypt-a-folder-or-filehttp://windows.microsoft.com/en-us/windows7/Encrypt-or-decrypt-a-folder-or-filehttp://windows.microsoft.com/en-us/windows7/Encrypt-or-decrypt-a-folder-or-filehttp://windows.microsoft.com/en-us/windows7/Encrypt-or-decrypt-a-folder-or-filehttp://windows.microsoft.com/en-US/windows7/Encrypting-File-System-EFS-recommended-linkshttp://windows.microsoft.com/en-US/windows7/Encrypting-File-System-EFS-recommended-linkshttp://windows.microsoft.com/en-US/windows7/Encrypting-File-System-EFS-recommended-linkshttp://windows.microsoft.com/en-US/windows7/Encrypting-File-System-EFS-recommended-linkshttp://windows.microsoft.com/en-US/windows7/Encrypting-File-System-EFS-recommended-linkshttp://windows.microsoft.com/en-US/windows7/Encrypting-File-System-EFS-recommended-linkshttp://windows.microsoft.com/en-US/windows7/Encrypting-File-System-EFS-recommended-linkshttp://windows.microsoft.com/en-US/windows7/Encrypting-File-System-EFS-recommended-linkshttp://windows.microsoft.com/en-US/windows7/Encrypting-File-System-EFS-recommended-linkshttp://windows.microsoft.com/en-US/windows7/Encrypting-File-System-EFS-recommended-linkshttp://windows.microsoft.com/en-US/windows7/Encrypting-File-System-EFS-recommended-linkshttp://windows.microsoft.com/en-US/windows7/Encrypting-File-System-EFS-recommended-linkshttp://windows.microsoft.com/en-US/windows7/Encrypting-File-System-EFS-recommended-links -
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Server-side vs. Client-side encryption
Whole disk encryption is an example of client-side
encryption (i.e., stored on client PC)
Encryption of databases residing on a server is anexample of server-side encryption
Two basic types ofdatabase encryption
1. Whole database (aka file-level) encryption
2. Column-level encryption
Database Encryption
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Features of whole database encryption:
Encrypts an entire database file
Secures files at rest not currently in use by a
database system (e.g., SQL Server, Oracle)
Without this, data in a DB file residing on a storage
disk can be viewed with text editor
Works at the O/S layer, so does not require
additional application program code
Simplest to implement
Minimal impact on database performance
File-level Database Encryption (1 of 5)
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A database without encryption:
File-level Database Encryption (2 of 5)
Source: NetLib Encryptionizer, http://www.netlib.com/how-it-works.asp
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DB file encrypted but not enabled:
File-level Database Encryption (3 of 5)
Source: NetLib Encryptionizer, http://www.netlib.com/how-it-works.asp
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DBMS enabled to process encrypted DB file:
File-level Database Encryption (4 of 5)
Source: NetLib Encryptionizer, http://www.netlib.com/how-it-works.asp
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Benefits ofcolumn-level encryption:
Encrypts individual columns of data within a table(e.g., SSN)
Enables more granular encryption by allowing a
group of users to only access part of table, whileencrypting other parts (e.g., employee table containingaddress book info + personal info)
Different columns can be encrypted with differentkeys
API enables customized programs to be writtenthat control who, when, where, how data isaccessed
Column-level Database Encryption (1 of 2)
Source: NetLib, http://www.netlib.com/column-vs-database.asp
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Limitations of column-level encryption:
Impact on performance(estimated at 5-6% slower thanaccess plaintext columns)
The more columns encrypted, the greater the
performance degradation
Performance may be significantly degraded forcomplex database queries on encrypted columns(e.g., LastName begins with S, Salary between $50,000 and $60,000)
Cannot protect the intellectual property of thedatabase (e.g., schema, views)
Column-level Database Encryption (2 of 2)
Source: NetLib, http://www.netlib.com/column-vs-database.asp
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Database activity monitoring (DAM):
Operates independently of DBMS
Monitors privileged user access (e.g., DBA)
Monitors application activity
Provides cyber-attack prevention
Establishing a baseline of normal application activity and SQLstructures and identifies when there is a diversion
Sample DAM vendor: Nitro Security
http://www.nitrosecurity.com/products/database-monitor/
Nitro Security acquired by MacAfee
http://www.networkworld.com/community/node/78826
Database Activity Monitoring
http://www.nitrosecurity.com/products/database-monitor/http://www.networkworld.com/community/node/78826http://www.networkworld.com/community/node/78826http://www.nitrosecurity.com/products/database-monitor/http://www.nitrosecurity.com/products/database-monitor/http://www.nitrosecurity.com/products/database-monitor/ -
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Encryption has two components:
1. Algorithm
Is typically publically available
2. Key
Is the parameter used in the algorithm that determines
how data will be transformed from plaintext to
cyphertext
Is kept secret
Is a very large number that should be impossible to
guess
Data Encryption
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The encryption key is the critical component in effectiveencryption
Key management is becoming increasingly challenging as
more encryption software is added to the storage
infrastructure due to increase in # of keys
Proper Encryption Key Management is Essential
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Effective key management is essential: Unauthorized access to keys renders encryption
useless
A lost key makes it impossible to retrieveencrypted data
Encryption key management involves managing
the key lifecycle
What is a keys lifecycle?
Proper Encryption Key Management is Essential
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Encryption key management involves thecreation, secure storage, handling, and deletion
of encryption keys
i.e., managing the key lifecycle
Proper Encryption Key Management is Essential
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Encryption key mgmt systems are intended to:
a) provide centralized management of an orgns encryptionkeys
b) manage the lifecycle of keys
c) store keys securely
d) distribute keys more easily
These systems are typically unable to manage keys from
disparate storage systems
Key mgmt standards are currently being developed
1) Key Management Interoperability Protocol (KMIP)
2) IEEE P1619.3 (for stored data)
Enterprise Encryption Key Management Systems
Cath Everett 2010
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Policies and procedures come first, and then
automated tools are used to enforce them.
Some key management policies:
1. Which group(s) should manage keys?2. How often should keys be changed?
3. Level of key granularity (i.e., different key per ___)
4. Segregation of duties
Encryption Key Management Policies & Procedures (1 of 2)
SearchStorage, Nov 2009
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Key management policies contd:
5. For encrypted data that must be archived, ensure
the key used to encrypt the data is stored securely
and accessible for X years
6. Backup keys in case system goes down
7. Plan for dealing with encrypted data in case of
merger, acquisition, or divestment
8. When outsourcing to ESP, must decide:
a) Encryption mechanism to use
b) Outsourcers role, if any, in key mgmt
Encryption Key Management Policies & Procedures (2 of 2)
Cath Everett 2010
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Where to manage and store keys
Hardware-based solutions store encryption keys on an
appliance, offering a centralized location.
Software-based encryption products store encryption
keys on the servers where the encrypted data is
locateda distributed approach to key storage
although some software vendors offer an optional
appliance for key storage. Centralized storage offers an easy target for attack, but
distributed storage is only as good as the most recent
security patch on your server.
Considerations for Encryption Key Storage
http://www.sqlmag.com/article/encryption2/database-encryption-solutions.aspx
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Key considerations for encryption controls: What data needs to be protected?
Where does this data reside? (Apps, servers,
databases, devices, etc.)
How should keys be managed? (where stored,
how many, accessible by whom)
What trade-offs are users willing to make for
performance vs. protection?
Considerations for Encryption Solutions
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One of two methods of encryption used:
1. Public key encryption (AKA asymmetric)
2. Secret key encryption (AKA symmetric)
Data Encryption
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Public key encryption
Two keys are necessary: a public key and a private
key
The public key is known to many people and is not
kept secret The private key must be kept secret
The two keys are used to code and decode
messages
A message coded with one can only be decoded
with the other
RSA is most common public key method
Asymmetric Key Encryption
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Public key encryption contd
The RSA method is provided in Web browsers
Full two-way secure communication requires both
parties to have a public and private key
Most B2C transactions are only secure from the
consumer to the merchant, since the consumer
likely does not have a private key
Asymmetric Key Encryption
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Asymmetric Key Encryption
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Asymmetric Key Encryption
Source: http://www.networksorcery.com/enp/data/encryption.htm
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Secret key encryption (AKA symmetric)
The sender and receiver use the same key to code
and decode a message
The level of security is a function of the size of the
key Common secret key algorithms used:
1. Data Encryption Standard (DES)
2. Triple DES (3DES)3. Advanced Encryption Standard (AES)
Symmetric Key Encryption
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Symmetric Key Encryption
Source: http://www.networksorcery.com/enp/data/encryption.htm
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Symmetric Key Encryption
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Digital signature
Since a private key is only known by the one party,
it can be used as a digital signature
RSA method used for private (secret) key
A certification agency must issue the keys in theform of a digital certificate containing:
a) Users name
b) Users public key
c) Digital signature of the certificate issuer
The digital certificate can be attached to a
message to verify the identity of the sender
Another Use of Encryption Keys
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Key extraction from monitoring cache memory
access patterns
http://web.mit.edu/newsoffice/2009/cryptography.html
The memory access patterns that is, which memoryaddresses are accessed are heavily influenced by the
specific secret key being used in that operation
AKA cache-timing attacks against AES
Researchers demonstrated a concise and efficient
procedure for learning the secret keys given just this crude
information about the memory access patterns.
Limitations with Encryption
http://web.mit.edu/newsoffice/2009/cryptography.htmlhttp://web.mit.edu/newsoffice/2009/cryptography.html
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