Pki & personal digital certificates, securing sensitive electronic communications, by nicholas davis, uw madison
PKI & Personal Digital Certificates, The Key to Securing Sensitive Electronic Communications MATC April 22, 2010 Nicholas Davis
OverviewWhy is electronic privacy such a hottopic these days?Watch videoWhat is a digital certificate?What is PKI?Why are these technologies important?Trusted Root AuthoritiesUsing digital certificates for email encryptionKey Escrow, the double edged swordIntegrating digital certificates into email forsecurityNew uses for digital certificatesHow is PKI related to SSL?Using certificates for code signing ofsoftwareNSA conspiracy theoriesReal world issues with PKIDiscussion
Why is Electronic PrivacySuch a Hot Topic Today? • Evolution of the Internet, commerce, banking, healthcare • Dependence on Email • Government regulations, SOX, HIPAA, GLB, PCI, FERPA • Public Image • Business warehousing • Industrial Espionage • The United States government!
The Topic is More Interesting When It Affects You!
Digital certificates can protect your sensitive electronic information in multiple WaysEncryption, Digital Signing and Authentication
Discussion Topic One• Do you think the threat of Email eavesdropping is real?• What about the government’s argument about Email being like a “postcard?”• Should DOA be allowed to look at DWD emails on a public network?• Are you angry now, or just afraid?• Who has the responsibility in this situation?
Digital Certificate Terminology Defined Digital Certificate Electronic Passport Good for authentication Good non-repudiation Proof of authorship Proof of non-altered content Encryption! Better than username - password
Public and Private Keys The digital certificate has two parts, a PUBLIC key and a PRIVATE key The Public Key is distributed to everyone The Private Key is held very closely And NEVER shared Public Key is used for encryption and verification of a digital signature Private Key is used for Digital signing and decryption
Getting Someone’s Public Key The Public Key must be shared to be Useful It can be included as part of your Email signature It can be looked up in an LDAP Directory Can you think of the advantages and disadvantages of each method?
What is PKI?• PKI is an acronym for Public Key Infrastructure• It is the system which manages and controls the lifecycle of digital certificates• The PKI has many features
What Is In a PKI? • Credentialing of individuals • Generating certificates • Distributing certificates • Keeping copies of certificates • Reissuing certificates • Revoking Certificates
Credentialing• Non technical, but the most important part of a PKI!• A certificate is only as trustworthy as the underlying credentialing and management system• Certificate Policies and Certificate Practices Statement
Certificate Generation and Storage • How do you know who you are dealing with in the generation process? • Where you keep the certificate is important
Distributing Certificates• Can be done remotely – benefits and drawbacks• Can be done face to face – benefits and drawbacks
Keeping Copies – Key Escrow • Benefit – Available in case of emergency • Drawback – Can be stolen • Compromise is the best! • Use Audit Trails, separation of duties and good accounting controls for key escrow
Certificate Renewal• Just like your passport, digital certificates expire• This is for the safety of the organization and those who do business with it• Short lifetime – more assurance of validity but a pain to renew• Long lifetime – less assurance of validity, but easier to manage• Use a Certificate Revocation List if you are unsure of certificate validity
Trusted Root Authorities• A certificate issuer recognized by all computers around the globe• Root certificates are stored in the computer’s central certificate store• Requires a stringent audit and a lot of money!
Using Certificates to Secure Email • Best use for certificates, in my opinion • Digital certificate provides proof that the email did indeed come from the purported sender • Public key enables encryption and ensures that the message can only be read by the intended recipient
Secure Email is Called S/MIME • S/MIME = Secure Multipurpose Mail Extensions • S/MIME is the industry standard, not a point solution, unique to a specific vendor
Digital Certificates• A digital passport, either contained on a secure device, or on a hard disk• Secured with a password, making them truly a dual factor solution• Can be used to authenticate machines as well as humans
Digital Certificate Benefits • True Dual Factor Authentication • Low variable cost to produce • Can contain authorization data as well as authentication data
Digital Certificate Drawbacks • High fixed cost to build initial infrastructure • Can be copied and shared if not properly stored • Expiration • Often require access to an interface such as a card reader of USB port, not always available at kiosks
Digital Signing of Email • Proves that the email came from you • Invalidates plausible denial • Proves through a checksum that the contents of the email were not altered while in transit • Provides a mechanism to distribute your public key • Does NOT prove when you sent the email
Using Digital Certificates for Digital Signing
Digital Signatures Do Not Prove Whena Message or Document Was Signed You need a neutral third party time stamping service, similar to how hostages often have their pictures taken in front of a newspaper to prove they are still alive!
Send Me a Signed Email, Please, I Need Your Public Key
What Does a Digital Signature Prove? Provides proof that the email came from the purported sender…Is this email really from Britney Spears? Provides proof that the contents of the email have not been altered from the original form
A Digital Signature Can Be Invalid For Many Reasons
Why Is The Digital Signature of the Sender So Important?
What if This Happens at MATC? Could cause harm in a critical situation Case Scenario Multiple hoax emails sent with Chancellor’s name and email. When real crisis arrives, people might not believe the warning. It is all about trust!
Digital Signing Summary• Provides proof of the author• Testifies to message integrity• Valuable for both individual or mass email• Supported by Wiscmail Web client (used by 80% of students)
What Encryption DoesEncrypting data with adigital certificateSecures it end to end.• While in transit• Across the network• While sitting on email servers• While in storage• On your desktop computer• On your laptop computer• On a server
Encryption Protects the Data At Rest and In Transit Physical theft from office Physical theft from airport Virtual theft over the network
Why Encryption is Important • Keeps private information private • HIPAA, FERPA, SOX, GLB compliance • Proprietary research • Human Resource issues • Legal Issues • PR Issues • Industrial Espionage • Over-intrusive Government • You never know who is listening and watching!
What does it actually look like in practice? -Sending-
What does it actually look like inpractice (unlocking my private key) -receiving-
What does it actually look like in practice? -receiving- (decrypted)
Digital Certificates For Machines Too • SSL – Secure Socket Layer • Protection of data in transit • Protection of data at rest • Where is the greater threat? • Our certs protect both!
Case Study - Why the Registrar’sOffice Chose Digital Certificates • Cost • Easy Integration • Security • No individual process evaluation • Leverages a central, generic resource • Ability to inter- communicate
Is the NSA Watching? • Discussion of NSA_key in Microsoft Operating System • What about UW-Madison?
SUMMARY• Authentication• Digital Signing of Documents• Encryption• Digital certificates can do all of this!
Benefits of Using Digital CertificatesProvide global assurance of your identity,both internally and externally to theUW-MadisonProvide assurance of message authenticityand data integrityKeeps private information private, end toend, while in transit and storageYou don’t need to have a digital certificateTo verify someone else’s digital signatureCan be used for individual or generic mailaccounts.
Who Uses Digital Certificates at UW-Madison?DoITUW Police and SecurityOffice of the RegistrarOffice of Financial AidOffice of AdmissionsPrimate Research LabMedical SchoolBucky Badger, because he’s a teamplayer and slightly paranoid about hisbasketball plays being stolen
Who Uses Digital Certificates Besides UW-Madison?US Department of DefenseUS Department of HomelandSecurityAll Western European countriesNew US PassportDartmouth CollegeUniversity of Texas at AustinJohnson & JohnsonRaytheonOthers
The Telephone AnalogyWhen thetelephone wasinvented, it washard to sell.It needed toreach criticalmass and theneveryone wantedone.
That All Sounds Great in Theory, But Do I Really Need It? • The world seems to get along just fine without digital certificates… • Oh, really? • Let’s talk about some recent stories
How Do Users Feel About the Technology? • Ease of use • Challenges • Changes in how they do their daily work • Benefits • Drawbacks
It Really Is Up To You!• Digital certificates / PKI is not hard to implement• It provides end to end security of sensitive communications• It is comprehensive, not a mix of point solutions• You are the leaders of tomorrow, make your choices count by pushing for secure electronic communications!
How Can I Help Youfirstname.lastname@example.org://www.cio.wisc.edu/security/digitalCert/