Public Key Infrastructure (PKI)

PKI is an ISO authentication “framework” that uses public keycryptography and X.509 standard protocols.

The framework establishes a generalized architecture forexchanging secure communication across networks. (Internet,internal / external).

PKI is a Hybrid Key System with an infrastructure allowing the PKIcertificate authority to create, maintain and manage digital

certificates.

Each user is issued a Digital Certificate (DC) which containsthe end users public key along with other identifying information.The Digital Certificate is signed / validated by a trusted third

party /Certificate Authority (CA). The CA enables users who are nottrusted to each other (unknown) to trust each other.

The most popular DC is an X.509 v3 This is same type of certificate as an SSL / HTTPS Certificate.

The certificate includes

Serial NumberVersion NumberIdentity InformationAlgorithm / Encryption InformationLifetime DatesSignature of the Certificate Authority (CA)

PKI through its “framework” can provide

ConfidentialityAccess ControlIntegrityAuthenticationNonrepudiation

Each end user can have multiple certificates, depending on levelof need, and users communicated with (64-bit 128-bit). This issimilar to PGP where key exchange levels are generally matched.

PKI is generally made up of the following entities / functions and roles

Certificate Authority (CA) Issuer of Certificates

Registration Authority (RA) Performs all functions of CA but cannotissue DC’s

Certificate Repository Structure used to hold CA’s

Certificate Revocation Part of CA / RA that manages DC’sIssuing System

Key Management Backup, recovery, change, updating,histories

Cross Certification Ring / Web of Trust with other CA’s

Time Stamping Provides Timeline / Auditing

Custom Application Software written with PKI logic includedSoftware in application / coding

One-Way Function

Algorithm that is easier to compute in one direction than theother. (ex. Drinking glass that is dropped and broken.)

RSA is an example of a real world implementation. (two primenumbers are difficult to derive from resultant)

Public Key / Asymmetric Cryptography is based on a Trapdoorfunction – Algorithm in conjunction with Private Key has proper information to decrypt Public Key.

Message Integrity

The detection through cryptographic means of determining or ensuringthat the message / data received is as sent – unaltered.

Extremely critical when downloading patches and system level applications.

Trojan attacks are extremely easy to unsuspecting users (ie OpenSSH).

One-Way Hash / Message Digest

Takes Cleartext in conjunction with a mathematical Algorithm and transforms it into a fixed length value commonly known as a Hash Value or Message Digest

Algorithm is usually publicly available / known. Algorithm is alsonormally based on prime numbers concept.

Receiver of Message and Hash run Message through Algorithm and compare results to Hash. If same – message can be taken asauthentic and unaltered.

One-Way hashing function does not use any type of key – is purely used for achieving same Hash Value on originally Hashed data stream / file.

SHA (Secure Hash Algorithm), MD{2,4,5} are examples of Hashes.

Message Authentication Code / Digital Signature

Ensures that only the intended recipient can view the hash value.

Uses a Symmetric Key to encrypt Hash Value.

Message is still sent Cleartext. Hash Value is used similar to a checksum.

RSA , DSA /SHA (Fed Standard – NIST) are most widely known.

End Result Choices / Options

What are you trying to accomplish ?

Confidentiality Encrypt Message

Integrity Hash Message

Authentication / Digitally SignedIntegrity

Confidentiality / Encrypt Message and Digitally SignAuthentication /Integrity

A simpler solution to fill in the gaps (on both ends) ?

Readily available tools / program allow all of the above to beaccomplished for novice and non-technical users (ex. Atabok,Amicus).

Protocols / Applications / Definitions

FIMAS Financial Institution Message Authentication Standard. Used toprotect electronic fund transfers – using MAC ANSI X9.9.

HTTP Hypertext Transfer Protocol. Is a stateless protocolthat functions atop TCP/IP

HTTPS HTTP-Secure. Is established at the Communication Layerof a session. This enables securing of both message andunderlying Communication Channel.

IOTP Internet Open Trading Protocol. C2B protocol. No realdefined standard – uses any encryption method agreedupon by both parties. Payment methods and uses vary.

IPSec Internet Protocol Security – method of setting up a securechannel for protected data exchange between two devices.

MONDEX Proprietary application developed by MONDEX Int’lCorp. Uses Smart Cards with currency amount stored onthe cards. Instant Cash – non smart card example – phonecards – gift cards.

MOSS MIME Object Security Services. Provides flexible email security withtrust models. Introduced in 1995. (See Email Security)

PEM Privacy Enhanced Mail. Standard Proposed by the IETF to be compatible

with PKCS. (See Email Security)

SET Secure Electronic Transaction. Developed by MC and Visa in 1997 as ameans of preventing fraud using electronic payments. SET providesconfidentiality for transactions using a DES Symmetric Key System.Developed to encrypt Credit Card Numbers across the internet.

S-HTTP Secure Hypertext Transfer Protocol. Protects individualdocuments as opposed to a full session like HTTPS.

SSH Secure Shell. A suite of applications that provide encryptedand secure protocols (telnet, ftp, r services, X 11)

SSID Service Set Identifier. All devices on a WLAN must use the same SSID(Network Name). Sent 32 character plaintext with data.

SSL Secure Socket Layer. Developed by Netscape in 1994.When using HTTPS you are using SSL.

S/MIME Secure Multipurpose Internet Mail Extensions. Provides authenticationvia digital signatures and the confidentiality of encryption. Uses PKCSstandards and uses X.509 standard for digital certificates. (See EmailSecurity)

TLS Transport Layer Security. Is the new name / standard forSSL. When using HTTPS you are now using TLS.

WAP Wireless Application Protocol. Cell phone / non 802.11 typearchitecture / standard.

WEP Wired Equivalent Privacy. Part of the 802.11 standard.

WML Wireless Markup Language. Used on WAP phones todisplay information in a browser / display. Similar to HTML.

WTLS Wireless Transport Layer Security. Is the layer of WAPthat provides privacy, data integrity and authentication ina WAP Services / Session Architecture. Is part of the WAPGap issue in WAP 1.0 .

Digital Certificates

Used to ensure that the entity you are transacting with is valid and “theoretically” secure.

Used by the entity you are transacting with to ensure you are valid,reputable, and in some instances authenticated.

Defined by the X.509 standard. The X.509 standard defines the formatof public key certificates.

Used with SSL, TLS, LDAP and PKI but can be used anywhere a CA (Certificate Authority) is maintained.

Server Gated Certificates (SGC) are used to elevate 40-bit SSLcertificates to 128-bit for the duration of the SSL session.

Most SSL certificates are managed and maintained server side –the client is superfluous.

Export restrictions are no longer an issue to non Terrorist – Watch Listentities.

Verisign is a digital certificate issuing authority.

Wireless Security

• WEP … just plain wrong

• Wired versus Wireless Security

• Hackability of Wireless

• Sniffing snooping and eavesdropping

• Wireless Attack Methods

• PDA’s, RIM’s, Cell Phones, GUI Gadgets and Portables

• Your Privacy / Your Rights

WEP … Just Plain Wrong

Wired Equivalent Privacy … need we say more ?

RC4 is a stream cipher – and it produces random output / ciphertext based on a fixed key size. RC4 rule is cipher cannever be reused. Data is unencrypted by XOR’ing Data with Keyon the other end of the transmission.

Since packets cannot be out of sync we need to either reset keyto beginning to compensate for missed packets or do a key perpacket (which should be a good idea). Add Intialization Vector (Random Number / Seed 24-bits long) to Key to give new perpacket key. Feel safer ??

Without going into all the logic (and way too much math) of why …

5k packets and random pooling having a 50 % repeat chance at4800 packets. Starting at a Key of 0 the climb lasts an hour (if

youwant to wait that long) or … with simple XOR logic we can guess

thekey. Or just download Airsnort and relax.

FYI … 802.11i does not fix the problem (cannot fix structural flaw).

Wired versus Wireless Security

Wired networks are logically defined and can be secured withphysical / logical security boundaries and best practices.

Wireless networks are not defined by physical or logical securitymethods (users are mobile) .

Network staff and Info Security tend to gravitate to wired securitysolutions for Wireless networks – ie change router passwordsbut not default SSID’s. Lack of understanding of issues and 802.11.

Anyone can bring in a wireless access point and hide it anywhere.

IT staff does not do perimeter sweeps or connectivity ranges. Firstthought is to turn off broadcasts on wireless.

MAC Address restriction is a double edged sword. Allows users /network more security but is limiting to visiting users. Defeated bycard cracking / switch flooding.

Concept of putting internal users in DMZ for wireless causes issues.

Tools used in wired security generally not used in wireless.

Users / Management and the oh it’s so cool factor (new toy mentality)

Hackability of Wireless

Denial of Service Similar to a Access Point Denial but morebroad ranged (users, network, multiple points).

Man in the Middle Since packets destination is on outside of encryted

data stream, you can disrupt, reroute, read, deny

or generally cause failures to all levels of business.

Access Point Denial Removing an Access Point from use by frequencyjam, TCP Resets, key count resetting.

Wireless NIC Denial Sending erroneous or disrupting information (done

at BlackHat briefings and does work).

Data Manipulation Man in the Middle with Data Change.

Sniffing snooping and eavesdropping

Airsnort Passively monitors the network and helps “recover”lost encryption keys. Once enough packets have beengathered – key recovery is less than a second. GPS capable.

Kismet Wireless sniffer similar to Airsnort – provides card detailsof Prism2, Orinco, Cisco, D-Link etc. Graphical plotting.

NetStumbler Another Sniffer – works with a variety of wireless cards.Second in use only to Airsnort.

WarDriving Traveling in a vehicle searching for wireless access points using a tool or tools listed above.

WarChalking Marking a spot / building where wireless access isfound / located.

WarParking Catching data / credit card numbers in a parking lot.(ie looking for the best buy).

Dinty Moore / Under 20 dollars – and with instructions – work betterPringles than purchased antennas.

Card Cracking Open the card – modify the MAC address / attach an antenna.

PDA’s, RIM’s GUI Gadgets, Cell Pones and Portables

A world of information in the palm of your (anyone’s) hands

Device Encryption / Password locking / Virus Protection

Network / Cradle Synchronization

Port 80 and your Cell Phone

RIM Devices

SIM / Cell phone Security

Windows / Linux Handhelds

Your Privacy / Your rights

Enhanced 911

SmartChips / Speed Pass / EZ-Pass

GPS Tracking

HIPPA – Doctors on the move

SPAM – Lunch is ahead