41641179 CISSP Notes Prep Guide

8/20/2019 41641179 CISSP Notes Prep Guide

1/98

CISSP Study Notes from CISSP Prep Guide

These notes were prepared from the The CISSP Prep Guide: Mastering the Ten Domains of ComputerSecurity by Ronald ! "rut#$ Russell Dean %ines$ &dward M! Stro# and are not intended to be areplacement to the boo'!

In addition to the CISSP Prep Guide I used the following resources to prepare for the e(am:

n The Information Security Management )andboo'$ *ourth &dition by Mic'i "rause and )arold *!Tipton

n The re+ised Michael ,+erly notes

n The -oson .uestions /0 and /1

n ots of misc! websites

n And of course www.cccure.org

Good uc'2

34G$ CISSP

CISSP STUDY NOTES !O" CISSP P!EP GUIDE ............... .............. .............. .............. .............. ...... .. #

DO"AIN # $ SECU!ITY "ANAGE"ENT P!ACTICES ............. .............. .............. ............. ...... ...... .... %

DO"AIN & $ ACCESS CONT!O' SYSTE"S ............. .............. .............. .............. .............. ............... ...... (

'ATTICE )ASED $ P!O*IDES 'EAST ACCESS P!I*I'EGES O T+E ACCESS PAI! ......... ... . ,

TYPES O )IO"ET!ICS ............. .............. .............. .............. .............. ............... .............. .............. ..... ..... #-

SING'E SIGN ON ............. .............. .............. .............. ............... .............. .............. .............. ..... ..... ..... ..... ... #-

CENT!A'IED .............. ............... .............. .............. .............. .............. .............. ............... ............. ..... ..... .. ##

C+AP $ C+A''ENGE +ANDS+A/E AUT+ENTICATION P!OTOCO' ............. ...... ..... ..... ...... ... #&

DECENT!A'IED ............. .............. ............... .............. .............. .............. .............. ............. ...... ..... ..... ..... . #&

!E'ATIONA' DATA)ASE SECU!ITY ............. .............. .............. .............. .............. .............. ....... ..... .. #&

!E'ATIONA' DATA)ASE ............. ............... .............. .............. .............. .............. ............... .............. ...... #&

SC+E"A ............. .............. .............. .............. ............... .............. .............. .............. .............. ............... ....... ... #&

ACCESS CONT!O' ISSUES ............. ............... .............. .............. .............. .............. .............. ............... .... #%

DO"AIN % $ TE'ECO" AND NET0O!/ SECU!ITY .............. ............... .............. ............. ..... ..... .... #1

ADDITIONA' DOS ATTAC/S2 ............. .............. .............. .............. .............. .............. ........ ..... ...... ...... ... #(

)UE! O*E!'O0 ATTAC/ ............. .............. .............. .............. ............... .............. ...... ..... ..... ...... ... #(

SYN ATTAC/ .............. .............. .............. .............. .............. ............... .............. .............. ............ ...... ...... ..... #,

TEA!D!OP ATTAC/ .............. .............. .............. .............. .............. .............. ............... .............. .......... ..... #,

S"U! ATTAC/ .............. .............. .............. .............. .............. ............... .............. .............. ............ ..... ..... . #,

!AGG'E ATTAC/ ............. .............. .............. .............. .............. ............... .............. .......... ...... ..... ..... ..... . #,

5


2/98

CO""ON SESSION +I3AC/ING ATTAC/S .............. .............. .............. .............. ......... ...... ...... ...... ... #,

INTE!NET 'AYE! P!OTOCO'S .............. .............. .............. .............. .............. .............. ...... ..... ...... ..... &&

DO"AIN 1 $ C!YPTOG!AP+Y .............. .............. .............. .............. .............. ............... ............. ..... ..... .. %4

DO"AIN 4 $ SECU!ITY A!C+ITECTU!E AND "ODE'S ............ ............... .............. ............ ...... ... 15

DO"AIN 6 $ OPE!ATIONS SECU!ITY .............. ............... .............. .............. .............. ............ ..... ..... ... 45DO"AIN 5 $ APP'ICATIONS AND SYSTE" DE*E'OP"ENT ............. .............. .............. .............. 61

OT+E!S2 ............. .............. .............. .............. .............. ............... .............. .............. .............. ....... ...... ...... ..... 5-

DO"AIN ( $ )USINESS CONTINUITY AND DISASTE! !ECO*E!Y P'ANNING ........... ..... ..... 5&

UNDE! 7NA"ED PE!I'S7 O!" O P!OPE!TY INSU!ANCE2 )U!DEN O P!OO T+AT

PA!TICU'A! 'OSS IS CO*E!ED IS ON INSU!ED ......................................................................... 5,

"A8I"U" TO'E!A)'E DO0NTI"E 9"TD:2 IT IS "A8I"U" DE'AY )USINESSES CAN

TO'E!ATE AND STI'' !E"AIN *IA)'E ......................................................................................... 5,

SYSTE" !E'IA)I'ITY IS INC!EASED )Y2 A +IG+E! "T) AND A 'O0E! "TT!. .... ... 5,

*A'UA)'E PAPE! INSU!ANCE CO*E!AGE DOES NOT CO*E! DA"AGE TO2 "ONEY

AND SECU!ITIES ..................................................................................................................................... 5,

A )USINESS CONTINUITY P'AN IS AN E8A"P'E O 0+IC+ O T+E O''O0ING; 2

CO!!ECTI*E CONT!O' ....................................................................................................................... 5,

UNDE! 7A'' !IS/7 O!" O P!OPE!TY INSU!ANCE2 )U!DEN O P!OO T+AT

PA!TICU'A! 'OSS IS NOT CO*E!ED IS ON INSU!E! ............................................................... 5,

A CONTINGENCY P'AN S+OU'D ADD!ESS2 !ESIDUA' !IS/S .............. .............. ............... .... 5,

)USINESS CONTINUITY AND DISASTE! !ECO*E!Y P'ANNING 9P!I"A!I'Y:

ADD!ESSES T+E2 A*AI'A)I'ITY O T+E CIA T!IAD .............. .............. .............. ........... ..... ..... 5,

DO"AIN , $ 'A0< IN*ESTIGATION AND ET+ICS .............. .............. .............. ............... ...... ...... ..... (-

#,,# US EDE!A' SENTENCING GUIDE'INES ............. .............. .............. .............. ............... ........... (6

P+ONE P+!EA/E!S .............. .............. .............. .............. ............... .............. .............. ............ ...... ...... ..... ((

DO"AIN #- $ P+YSICA' SECU!ITY ............. .............. .............. .............. .............. ............... ......... ..... .. (,

0


3/98

Dom=in # $ Security "=n=gement Pr=ctices

T>e )ig T>ree ? C. I. A.

n Confidentiality 6 Pre+ent disclosure of datan Integrity 6 Pre+ent modification of datan 7+ailability 6 &nsure reliable timely access to data

Ot>er Import=nt Concepts

n Identification 6 Means in which user claims Identityn 7uthentication 6 &stablishes the users Identityn 7ccountability 6 Systems ability to determine actions of users

n 7uthori#ation 6 rights and permissions granted to an indi+idualn Pri+acy 6 e+el of confidentiality that a user is gi+en

,b8ecti+e of Security is to reduce effects of threats and +ulnerabilities to a tolerable le+el!

!is@ An=ysis

7ssess the following:n Impact of the threat

n Ris' of the threat occurring 9li'elihood

Controls reduce both the impact of the threat and the li'elihood of the threat$ important in cost benefit ofcontrols!

D=t= C=ssific=tion

n Data classification has high le+el enterprise wide benefitn Demonstrates organi#ations commitment to securityn )elps identify sensiti+e and +ital informationn Supports C!I!7!

n May be re;uired for legal regulatory reasons

Data owners are responsible for defining the sensiti+ity le+el of the data!

GoBernment C=ssific=tion Terms2

n


4/98

Distriution m=y e reuired in t>e eBent of t>e foowing:n Court ,rder 6 may be re;uired by court order n Go+ernment Contracts 6 go+ernment contractors may need to disclose classified informationn Senior e+el 7ppro+al 6 senior e(ecuti+es may appro+e release

Inform=tion C=ssific=tion !oesOwner

n May be e(ecuti+e or manager

n ,wner has final corporate responsibility of the data protectionn Ma'es determination of classification le+eln Re+iews classification le+el regularly for appropriatenessn Delegates responsibility of data protection to the Custodian

Custodi=n

n Generally IT systems personneln Running regular bac'ups and testing reco+eryn Performs restoration when re;uiredn Maintains records in accordance with the classification policy

User

n 7nyone the routinely uses the datan Must follow operating proceduresn Must ta'e due care to protectn Must use computing resources of the company for company purposes only

Poicies St=nd=rds< Guideines =nd Procedures

n Policies are the highest le+el of documentationn Standards$ Guidelines and Procedures deri+ed from policiesn Should be created first$ but are no more important than the rest

Senior "=n=gement St=tement $ gener= >ig>?eBe st=tement

n 7c'nowledgment of importance of computing resources

n Statement of Support for information securityn Commitment to authori#e lower le+el Standards$ Guidelines and Procedures

!egu=tory Poicies 6 company is re;uired to implement due to legal or regulatory re;uirementsn


5/98

n Specify use of technology in a uniform way$ compulsory

Guideines 6 similar to standards but not compulsory$ more fle(ible

Procedures 6 Detailed steps$ re;uired$ sometimes called ?practices@$ lowest le+el

)=seines 6 baselines are similar to standards$ standards can be de+eloped after the baseline is established

!oes =nd !esponsiiities

n Senior Management 6 )as ultimate responsibility for security

n Infosec ,fficer 6 )as the functional responsibility for securityn ,wner 6 Determines the data classificationn Custodian > Preser+es C!I!7!n


6/98

Preimin=ry Security E=min=tion 9PSE:

n ,ften conducted prior to the ;uantitati+e analysis!n PS& helps gather elements that will be needed for actual R7

!is@ An=ysis Steps

5 &stimate of potential loss0 7naly#e potential threats1 Define the 7nnuali#ed oss &(pectancy 97&

C=tegories of T>re=ts

n Data Classification 6 malicious code or logic

n Information 4arfare 6 technically oriented terrorismn Personnel 6 implementation of controls to alter ris' position

n !is@ Tr=nsference 6 get insurance$ transfer cost of a loss to insurance!is@ Accept=nce $ 7ccept the ris'$ absorb loss

u=it=tiBe Scen=rio Proceduren Scenario ,rientedn ist the threat and the fre;uencyn Create e(posure rating scale for each scenarion Scenario written that address each ma8or threat

n Scenario re+iewed by business users for reality chec' n Ris' 7nalysis team e+aluates and recommends safeguardsn 4or' through each finali#ed scenarion Submit findings to management

*=ue Assessment

n 7sset +aluation necessary to perform costEbenefit analysisn =ecessary for insurance

n Supports safeguard choices

S=fegu=rd Seection

n Perform costEbenefit analysisn Costs of safeguards need to be considered includingn Purchase$ de+elopment and licensing costsn Installation costsn Disruption to productionn =ormal operating costs

F


7/98

Cost )enefit An=ysis

7& 9PreControl 6 7& 9PostControl 7nnuali#ed +alue of the control

'eBe of m=nu= oper=tions

n The amount of manual inter+ention re;uired to operate the safeguardn Should not be too difficult to operate

Audit=iity =nd Account=iity

Safeguard must allow for auditability and accountability

!ecoBery Aiity

n During and after the reset condition

n =o asset destruction during acti+ation or resetn =o co+ert channel access to or through the control during resetn =o security loss after acti+ation or resetn Defaults to a state that does not allow access until control are fully operational

Security Aw=reness Tr=ining

-enefits of 7warenessn Measurable reduction in unauthori#ed access attempts

n Increase effecti+eness of controln )elp to a+oid fraud and abuse

Periodic awareness sessions for new employees and refresh other

"et>ods of =w=reness improBement

n i+e interacti+e presentationsn C-Tsn Publishing of posters and newslettersn Incenti+es and awards

n Reminders$ login banners

Tr=ining H Educ=tion

n Security training for ,peratorsn Technical trainingn Infosec trainingn Manager training


8/98

Dom=in & $ Access Contro Systems

C > ConfidentialityI > IntegrityA > 7+ailability

Confidenti=ity

n =ot disclosed to unauthori#ed person

Integrity

n Pre+ention of modification by unauthori#ed usersn Pre+ention of unauthori#ed changes by otherwise authori#ed users

n Internal and &(ternal Consistencyn Internal Consistency within the system 9i!e! within a database the sum of subtotals ise;ual to the sum of all unitsn &(ternal Consistency 6 database with the real world 9i!e! database total is e;ual to theactual in+entory in the warehouse

AB=i=iity

n Timely access

Three things to consider n Threats 6 potential to cause harmn %ulnerabilities 6 wea'ness that can be e(ploitedn Ris' 6 potential for harm

Contros

n Pre+entati+e 6 pre+ent harmful occurrencen Detecti+e 6 detect after harmful occurrencen Correcti+e 6 restore after harmful occurrence

Contros c=n e2

n 7dministrati+e 6 polices and procedures

n ogical or Technical > restricted accessn Physical 6 loc'ed doors

T>ree types of =ccess rues2

5! "=nd=tory =ccess contro 9"AC:2 7uthori#ation of sub8ectHs access to an ob8ect depends on labels9sensiti+ity le+els$ which indicate sub8ectHs clearance$ and the classification or sensiti+ity of the ob8ect

&+ery ,b8ect is assigned a sensiti+ity le+elElabel and only users authori#ed up to that particular le+el can access the ob8ect

7ccess depends on rules and not by the identity of the sub8ects or ob8ects alone

,nly administrator 9not owners may change category of a resource ,range boo' ->le+el

,utput is labeled as to sensiti+ity le+el


9/98

Identity -ased 7C

%. Non?Discretion=ry Access Contro2 Central authority determines what sub8ects can ha+e access tocertain ob8ects based on organi#ationHs security policy 9good for high turno+er

May be based on indi+idualHs role in the organi#ation 9Role>-ased or the sub8ectHsresponsibilities or duties 9tas'>based

'=ttice =sed $ pro+ides least access pri+ileges of the access pair n Greatest lower bound

n owest upper bound

PreBent=tiBe DetectiBe

Administr=tiBe Policies and procedures$ pre>employment bac'ground chec's$strict hiring practices$ employmentagreements$ friendly andunfriendly employee termination procedures$ +acation scheduling$labeling of sensiti+e materials$

increased super+ision$ securityawareness training$ beha+iorawareness$ and sign>up proceduresto obtain access to informationsystems and networ's!

Polices and procedures$ 8obrotation$ sharing of responsibilities

Tec>nic= ogical system controls$ smartcards$ bio>metrics$ menu shell

IDS$ logging$ monitoring$ clippingle+els

P>ysic= Restrict physical access$ guards$man trap$ gates

Motion detectors$ cameras$ thermaldetectors

Identific=tion =nd Aut>entic=tion

Identification establishes accountability

T>ree =ctor Aut>entic=tion

n Something you 'now 9passwordn Something you ha+e 9to'enn Something you are 9biometricsSometimes > something you do

P=sswords

n Static 6 same each time

n Dynamic 6 changes each time you logon

To@ens $ Sm=rtc=rds

Static Password 9li'e software with pinn ,wner 7uthenticates to the to'enn To'en authenticates to the system

Sync>ronous Dyn=mic P=ssword

n To'en 6 generates passcode +aluen Pin 6 user 'nowsn To'en and Pin entered into PCn Must fit in +alid time window

K


10/98

Async>ronous

n Similar to synchronous$ new password is generated asynchronously$ =o time window

C>=enge !esponse

n System generates challenge stringn +essel pattern of the retina on the bac'side of the eyeball!n Iris Sc=ns2 Scan the colored portion of the eye that surrounds the pupil!

n =ci= Sc=ns2 Ta'es attributes and characteristics li'e bone structures$ nose ridges$ eye widths$forehead si#es and chin shapes into account!

n P=m Sc=ns2 The palm has creases$ ridges and groo+es throughout it that are uni;ue to a specific

person!n +=nd Geometry2 The shape of a personHs hand 9the length and width of the hand and fingers

measures hand geometry!n *oice Print2 Distinguishing differences in peopleHs speech sounds and patterns!n Sign=ture Dyn=mics2 &lectrical signals of speed and time that can be captured when a person writes a

signature!n /eyo=rd Dyn=mics2 Captures the electrical signals when a person types a certain phrase!n +=nd Topoogy2 oo's at the si#e and width of an indi+idualHs hand and fingers!

Singe Sign On

/ereros

n Symmetric 'ey encryptionn "DC 6 "erberos>trusted "ey Distribution Center

n TGS 6 Tic'et Granting Ser+icen 7S 6 7uthentication Ser+er

/ereros

5! "DC 'nows secret 'eys of Client and Ser+er 0! "DC e(changes info with the Client and the Ser+er using symmetric 'eys1!


11/98

Initi= Ec>=nge

Client sends )ash Password to the TGS Ser+er$ TGS +erifies with the 7uth! Ser+er TGS Ser+er responds with:5 "ey for Client and TGS ser+er encrypted with Client "ey "9c$tgsN"c0 Tic'et Granting Tic'et 9TGT "9c$ tgs$ c$a$+N"9tgs

!euest for SerBice

Client sends re;uest for ser+ice to TGS with5 TGT "9c$ tgs$ c$a$+N"9tgs0 7uthenticator "9c$ tgs

TGS Issues Tic@et for SerBice

TGS sends Client bac' tic'et for ser+er and authenticator for ser+er 5 Tic'et T9c$s s$c$a$+$"9c$sN"s0 "9c$sN"9c$tgs

!eceiBe SerBice from SerBer

Client sends Ser+er 5 Tic'et T9c$s s$c$a$+$"9c$sN"s0 authenticator c$t$'eyN"9c$s

/ereros we=@nesses

n Replay is possible within time framen TGS and 7uth ser+er are +ulnerable as they 'now e+erythingn Initial e(change passed on password authenticationn "eys are +ulnerable

SESA"E 6 Secure &uropean System for 7pplications in a Multi>+endor &n+ironmentn Schroeder protocoln t

n Peer to peer relationship between "DC 6 "ey Distribution Center and parties 9Client and Ser+ern =etSP is based on "rypto"nightn Supported by R7C*n 7uthentication

n "ey Distributionn Data Pri+acyn Data Integrityn Single Sign>,nn 7dministration

Access Contro ? Centr=iFed =nd Decentr=iFed

Centr=iFed

n R7DI Remote 7ccess Dial>In


12/98

n T7C7CSO 6 Terminal 7ccess Controller 7ccess Control System Plus$ supports to'en authentication

C+AP $ C>=enge +=nds>=@e Aut>entic=tion Protoco

n Supports encryption$ protects password

Decentr=iFed

!e=tion= D=t==se Security

n Relational Databases support ;ueriesn ,b8ect oriented databases do not support ;ueries

!e=tion= D=t==se

n Data structures called tables 9relations

n Integrity Rules on allowable +aluesn ,perators on the data in tables

Persistency 6 preser+ation of integrity through the use of non+olatile storage media

Sc>em=

n Description of the databasen Defined by Data Description ayer 9DD

D=t==se "=n=gement System 9D)"S:

n pro+ides access to the databasen 7llows restriction of access

!e=tion= D=t==se

n Relation 9table is the basis of a relational database 6 relation is represented by a tablen Rows Records 9tuplesn Column 7ttributes

Attriute?# Attriute?& Attriute?%

!ecord?#

!ecord?&

Prim=ry /ey

n 8oin tables based on a common +aluen Union 6 forms a new relation 9table from two other relationsn *iew 6 9+irtual table uses 8oin$ pro8ect$ select > %iews can be used to restrict access 9least pri+ilegesuery p=n

n Comprised of implementation procedures$ lowest cost plan based on ?cost@

50


13/98

n Costs are CP< time$ Dis' 7ccessn )ind 6 used to create plan

D=t= Norm=iF=tion

&nsures that attributes in a table rely only on the primary 'eyn &liminates repeating groupsn &liminates redundant datan &liminates attributes not dependent on the primary 'ey

S' $ Structured uery '=ngu=ge

n Selectn


14/98

Dom=in % $ Teecom =nd Networ@ Security

Management ConceptsTechnology Concepts

n Confidentiality 6 no disclosure of datan Integrity 6 no alteration of datan 7+ailability 6 no destruction of data

!emote Access Security "=n=gement

!emote Connections

n (DS 6 Digital Subscriber inen Cable modemn 4ireless 9PD7sn ISD= 6 Integrated Ser+ices Digital =etwor'

Securing Etern= !emote Connections

n %P= 6 %irtual Pri+ate =etwor' n SS 6 Secure Soc'et ayer

n SS) 6 Secure Shell

!emote Access Aut>entic=tion

n R7DIIn entic=tion

n P7P 6 Password 7uthentication Protocol 6 clear te(tn C)7P 6 Challenge )andsha'e 7uthentication Protocol 6 protects password

!emote User "=n=gement

n 3ustification of remote accessn Support Issues

n )ardware and software distribution

Intrusion Detection

n =otificationn Remediation

Cre=tion of2

n )ost and networ'ed based monitoringn &+ent =otificationn CIRT 6 Computer Incident Response Team

n CIRT Performsn 7nalysis of e+entn Response to incident

n &scalation path proceduresn Resolution 6 post implementation follow up

Intrusion Detection Systems

n Networ@ )=sed 6 Commonly reside on a discrete networ' segment and monitor the traffic on thatnetwor' segment!

n +ost )=sed 6


15/98

/nowedge )=sed

Pros Cons

ow false alarms Resource Intensi+e

7larms Standardi#ed =ew or uni;ue attac'snot found

)e>=Bior )=sed $ ess common

Pros Cons

Dynamically adapts )igh *alse 7larm rates

=ot as operating systemspecific

the only current standard$ *ailure TolerantDis' Systems$ and Disaster Tolerant Dis' Systems!

n !DS: pro+ides the ability to reconstruct the contents of a failed dis' onto a replacement dis'!n &nables the continuous monitoring of these parts and the alerting of their failure

n *RDSOn Protect from dis' failure 6 can reconstruct dis's by automatically hot swapping whileser+er is runningn Includes en+ironmental

n *RDSO adds ha#ard warnings

!AID 'eBes

!AID - 9ST!IPPING:

n Creates one large dis' by using multiple dis's 6 stripingn =o redundancy

n =o fault tolerance 95 fail all failn ReadE4rite performance is increased

5


16/98

!AID # 9"I!!O!ING:

n Mirroringn Duplicates data on other dis's 9usually one to one ration &(pensi+e 9doubles cost of storage

!AID & 9+A""ING CODE PA!ITY:

n Multiple dis'sn Parity information created using a hamming coden Can be used in 1K dis' array 10 Data and reco+eryn =ot used$ replaced by more fle(ible le+els

!AID % 9)YTE 'E*E' PA!ITY: !AID 1 9)'OC/ 'E*E' PA!ITY:

n R7ID 1 6 -yte le+eln R7ID A 6 -loc' le+eln Stripe across multiple dri+esn Parity information on a parity dri+en Pro+ides redundancyn Can affect performance with single parity dri+e

!AID 4 9INTE!'EA*E PA!ITY:

n Most popular n Stripes data and parity information across all dri+esn


17/98

)=c@up "et>odoogies

u )=c@ Up 6 e+ery file

Increment=

n ,nly files that ha+e been changed or added recentlyn ,nly files with their archi+e bit set are bac'ed up!n This method is fast and uses less tape space but has some inherent +ulnerabilities$ one being that all

incremental bac'ups need to be a+ailable and restored from the date of the last full bac'up to thedesired date should a restore be needed!

n Restore last full bac'up plus each incremental

Differenti=

n ,nly files that ha+e changed since the last bac'upn 7ll files to the full bac'up 9additi+en Restore full bac'up plus the last differential

Types of T=pe

n D7T 6 Digital 7udio Tape

n .IC 6 .uarter Inch Cartridge 6 Small and slown Jmm Tape 6 Superceded by DTn DT 6 Digital inear Tape 6 Amm tape 6 large and fast

Ot>er medi=

CD 6 permanent bac'ups$ longer shelf life than tapeIP 6 37 6 CommonTape 7rray 6 10 to F1 Tape 7rray using R7ID technology)SM 6 )ierarchical! Pro+ides a continuous on>line bac'up by using optical or tape 8u'ebo(esH$ similar to4,RMs!

Common )=c@up Proems

n Slow transfer of data to bac'up

n Retrie+al time to restoren ,ff hour processing and monitoring

n Ser+er dis' space e(pands o+er timen oss of data between last bac' upn Physical security of tapes

Singe Points of =iure

Cabling *ailures6n Co=i=: many wor'stations or ser+ers attached to the same segment of cable$ which creates a single

point of failure if it is bro'en 9similar to cable T% cabling! &(ceeding cable length is a source offailure!

n Twisted P=ir: 9C7T1 and C7T The difference between the two has to do with the tightness thecopper wires are wound! Tightness determines its resistance to interference! C7T1 is older! Cable

length is a common failuren ier Optic: Immune to &MI! onger usable length 9upto 0'ms! Drawbac' is costs!

Tec>noogy =iures

Et>ernet

n Most Popular n &(tremely resistance to failure$ especially in a star>wired config!

To@en !ing

n Since to'en is passed by e+ery station on the ring

5


18/98

n =IC set at wrong speed or in error state can bring the networ' down

DDI $ ier Distriuted D=t= Interf=ce

n Dual rings fault tolerance 9if first ring fails$ the secondary ring begins wor'ing

n Sometimes uses second ring for impro+ed performance

'e=sed 'ines

T5 and ISD= 6 go with multiple +endors to reduce failures

r=me !e=y

n Public switched 47=n )ighly *ault Tolerant

n -ad segment di+erts pac'etsn Can use multiple +endors for high a+ailability

Ot>er Singe Points of =iure

n Can be any de+ice where all traffic goes through a single de+ice > Router$ firewall$ hub$ switchn Power failure 6 surges$ spi'es 6 install oriFed =ccess t>roug> circumBention of security =ccess contros. Mas;uerading$logon abuse 9primarily internal attac'sC=ss ) 6 non?usiness use of systemsC=ss C 6 E=Besdropping

n ActiBe: Tampering with a transmission to create a co+ert signaling channel or probing thenetwor' n P=ssiBe: Co+ertly monitoring or listening to transmissions that is unauthori#ed!n CoBert C>=nne: using a hidden unauthori#ed communication

n T=pping2 refers to the physical interception of a transmission medium 9li'e splicing ofcable!

C=ss D 6 Deni= of SerBice S=tur=tion of networ@ serBices

C=ss E 6 Networ@ Intrusion 6 penetration 9e(ternallyn Spoofing 6 7 spoofing attac' in+ol+es nothing more than forging ones source address! Itis the act of using one machine to impersonate another!n Piggy )=c@ing 6 attac' using another users connectionn )=c@ Door 6 attac' +ia dial up or e(ternal connection

C=ss 6 Proingn Gi+es an intruder a road map of the networ' for DoS attac' n Gi+es a list of a+ailable ser+icesn Traffic analysis +ia sniffersH which scans the host for a+ailable ser+ices

n i'e a telephone wiretap allows the *-I to listen in on other peoples con+ersations$ aUsniffingU program lets someone listen in on computer con+ersations!

n Tools: Telnet 9manual$ +ulnerability scanners 9automatic!

Common DoS Att=c@sn *illing hard dri+e space with email attachmentsn Sending a message that resets a targets host subnet mas' causing routing disruptionn


19/98

n PI=G 6 Pac'et Internet Groper 6 uses ICMP 6 Internet Control Message Protocoln PI=G of Death> Intruder sends a PI=G that consists of an illegally modified and +ery large IP

datagram$ thus o+erfilling the system buffers and causing the system to reboot or hang!SYN Att=c@

n 7ttac's the buffer space during a Transmission Control Protocol 9TCPn 7ttac'er floods the target systemHs in>processH ;ueue with connection re;uests causing the system to

time>out!Te=rdrop Att=c@

n Modifying the length of the fragmentation fields in the IP Pac'etn 4hen a machine recei+es this attac'$ it is unable to handle the data and can e(hibit beha+ior ranging

from a lost Internet connection to the infamous blue screen of death! -ecomes confuse and crashes!Smurf Att=c@

n 9Source Site Sends spoofed networ' re;uest to large networ' 9bounce site all machines respond to the9target site! IP broadcast addressing!

r=gge Att=c@

n The UsmurfU attac's cousin is called UfraggleU$ which uses Security Domains

Tec>noogy Concepts

Protocos2 is a standard set of rules that determines how computers communicate with each other acrossnetwor's despite their differences 9PC$


20/98

OSI $ Open Systems Interconnect "ode

'=yer 5 Appic=tion

Security: Confidentiality$authentication$ data integrity$ non>repudiationTec>noogy: gateways

Protocos: *TP$ SM-$ T&=&T$ T*TP$SMTP$ )TTP$ ==TP$ CDP$ G,P)&R$S=MP$ =DS$ 7*P$ S7P$ =CP$ S&T

n Responsible for all application>to>application communications! noogy: gatewaysProtocos: Remote Procedure Calls9RPC and S.$ R7DInoogy: gatewaysProtocos: TCP$ 0$SPV$ =et-ios$ 7TP

n Responsible for the guaranteeddeli+ery of user information! It isalso responsible for error detection$correction$ and flow control! in' layer! M7C and C!The Data>in' layer has errordetection$ frame ordering$ and flowcontrol!


21/98

OSI '=yers

n Process down the stac' and up the stac' n &ach layer communicates with corresponding layer through the stac'!

OSI Security ? 6 Security SerBices. A security serBice is = coection of security mec>=nisms< fies<

=nd procedures t>=t >ep protect t>e networ@.

n 7uthenticationn 7ccess controln Data confidentialityn Data integrityn =on>repudiation

n ogging and monitoring

OSI Security ? ( Security "ec>=nisms. A security mec>=nism is = contro t>=t is impemented in

order to proBide t>e 6 =sic security serBices.

n &nciphermentn Digital signaturen 7ccess Controln Data Integrity

n 7uthenticationn Traffic Paddingn Routing Controln =otari#ation

TCPKIP $ Suite of Protocos

OSI TCPKIP Protocos Description

7pplication7pplication ayer

Consists of the applications and processes that use the networ'!Presentation

Session

Transport )ost to )ostTCP and

to>end data deli+ery ser+iceto the 7pplication ayer!

=etwor' Internet ayer IP$ 7RP$R7RP$ICMP

Defines the IP datagram and handles therouting of data across networ's!

Data lin'

=etwor' 7ccess

Consists of routines for accessing physical networ's and the electricalconnection!Physical

+ost?to?+ost Tr=nsport '=yer Protocos2

TCP $ Tr=nsmission Contro Protoco

n Connection ,rientedn Se;uenced Pac'etsn 7c'nowledgment is sent bac' for recei+ed pac'ets

n If no ac'nowledgement then pac'et is resentn Pac'ets are re>se;uencedn Manageable data flow is maintained

NOTE2 TCP =nd UDP use port numers gre=ter t>=n #-&%

UDP

n -est effortn DoesnHt care about se;uence order

05


22/98

n Connectionlessn ess o+erhead and faster than TCP

Internet '=yer Protocos

IP $ Internet Protoco

n 7ll hosts on a networ' ha+e an IP addressn &ach data pac'et is assigned the IP address of the sender and recei+er n It pro+ides an unreliable datagram ser+iceH! Pro+ides:

n =o guarantees that the pac'et will be deli+eredn =o guarantee that the pac'et will be deli+ered only oncen =o guarantee that it will be deli+ered in the order which it was sent

A!P $ Address !esoution Protoco

n er TCPKIP Protocos

n Tenet 6 Terminal &mulation 9=o *ile Transfern TP 6 *ile Transfer Protocol 6 9Can not e(ecute files

n TTP 6 Tri+ial *TP 6 no directory browsing capabilities$ no authentication 9it is unsecure$ can onlysend and recei+e files!

n Some sites choose not to implement T*TP due to the inherent security ris's!n T*TP is an based file transfer program that pro+ides no security!

n NS 6 =etwor' *ile Sharing

n S"TP 6 Deli+ers emailsn 'DP 6 ine Printer Daemon 6 with PR enables print spoolingn 8?0indows 6 for writing graphical interface applicationn SN"P 6 Simple =etwor' Management Protocol

n Pro+ides for the collection of networ' information by polling the de+ices on the networ'from a management station!n Sends S=MP traps 9notification to MI-S Management Information -ases

n )ootstr=p 9)ootP: protoco 6 Dis'less boot up! -ootP ser+er hears the re;uest and loo's up the

clientHs M7C address in its -ootP file! ItHs an internet layer protocol!

Security En>=nced Protocos 9Two types:

Security enhancements to telnet such as remote terminal access and secure telnetSecurity enhancements to Remote Procedure Call such as Secure RPC 7uthentication

*ollowing Security Protocols:At t>e Appic=tion '=yer 9OSI "ode:

SET $ Secure Eectronic Tr=ns=ction

n ,riginated by %isa and MasterCard

00


23/98

n -eing o+erta'en by SS

S+TTP ? Secure +TTP

n &arly standard for encrypting )TTP documents

n 7lso being o+erta'en by SS

At t>e Tr=nsport '=yer 9OSI "ode:

SS+?&

n SS) has RS7 Certificatesn Supports authentication$ compression$ confidentiality$ and integrityn D&S &ncryptionn -ecause Secure Shell 9SS)>0 supports authentication$ compression$ confidentiality$ and integrity$

SS) is used fre;uently for &ncrypted *ile Transfer

SS' $ Secure Soc@et '=yer

n Contains SS record protocol and SS )andsha'e Protocoln ird Gener=tion

n Pac'ets 7naly#ed at all ,SI layersn .ueued at the networ' le+eln *aster than 7pplication le+el Gateway

Dyn=mic P=c@et itering irew=s $ ourt> Gener=tion

n 7llows modification of security rulesn Mostly used for


24/98

irew= Arc>itectures2

P=c@et itering !outers2

n Sits between trusted and untrusted networ'sn homed

-astion host

InternalRouter


25/98

Screened Sunet irew=

n ,ne of the most securen Two pac'et filtering routers and a -astion )ostn Pro+ides networ' layer 9pac'et filtering andapplication layer 9pro(y ser+icesn Pro+ides DMn Comple( configuration

SOC/S SerBer

n Circuit le+el pro(y ser+er n Re;uires S,C"S client on all machinesn 5K5n Class C addresses are for small networ's 9fewer than 0F de+ices! 5K0>001n Class D addresses are multicast addresses.

*irtu= PriB=te Networ@s2

n Secure connection between two nodes using secret encapsulation method!n Secure &ncrypted Tunnel 6 encapsulated tunnel 9encryption may or may not be usedn Tunnel can be created by the following three methods:

n Installing software or agents on client or networ' gateway!

n Implementing user or node authentication systems!n Implementing 'ey and certificate e(change systems!

*PN Protoco St=nd=rds2

PPTP $ Point?to?Point Tunneing Protoco

n 4or's at the Data in' ayer n Single point to point connection from client to ser+er

n Common with asynchronous connections with =T and 4in K

'&TP ? '=yer & Tunneing Protoco

n Combination of PPTP and earlier ayer 0 *orwarding Protocol 90*n Multiple protocols can be encapsulated within the 0TPn Single point to point connection from client to ser+er n Common with Dial up %P=s

IPSecn ,perates at the networ' layer n 7llows multiple and simultaneous tunnelsn &ncrypt and authenticate IP datan *ocuses more on =etwor' to =etwor' Connecti+ity

*PN DeBices

n )ardware and Software de+ices that utili#e %P= Standardsn Two types: IPSec Compatible and =on>IPSec Compatible

0

homed-astion host

InternalRouter

DM


26/98

IPSec Comp=tie

n Installed on a networ's perimeter and encrypt traffic between the twon -ecause IPSec only wor' with IPn ,perate at =etwor' ayer

n Two "odes:n Tunne "ode 6 entire pac'et is encrypted and encases in IPSec pac'etn Tr=nsport "ode 6 ,nly datagram is encrypted lea+ing IP address +isible!

n D=t=gr=m: 7 self>contained$ independent entity of data carrying sufficient information to be routedfrom the source to the destination!

Non?IPSec Comp=tie

n Common non>IPSec compatible include S,C"S$ PPTP and SS)

n S,C"S is not traditional %P= protocol but is robust and operates at 7pplication ayer!n PTP implemented in 4inK and =T

n Multiprotocol and uses P7P and C)7P user authentication!n Compresses Datan &nd>to>&nd encryption

n Secure Shell SS)>0n =ot strictly %P= but can be used as one with Terminal Session

irew= )=sed *PNs

n *re;uently a+ailable with Third Generation 9Stateful Inspection *irewallsn ,perate at the 7pplication layer n Performance degradation is often a problem

D=t= Networ@ing )=sics

D=t= Networ@ Types2

n ocal 7rea =etwor' 97=n 4ide 7rea =etwor' 947=

n Internet$ Intranet$ and &(tranet

'oc= Are= Networ@s $ 'AN

n Discrete networ' for limited geographical area li'e a building or a single floor n Two most popular 7=s are:

n CAN ? C=mpus Are= Networ@ 6 connects multiple buildings with each other o+erswitched bac'bonen "AN $ "etropoit=n Are= Networ@ 6 7= o+er a city wide metropolitan area!

n -oth C7= and M7= can ha+e a connection to 47=

0ide Are= Networ@s ? 0AN

n =etwor' of sub networ's that interconnect 7=s o+er large geographic areas!n 47= is basically e+erything outside of 7=

Internet

n The Internet is a 47= originally funded by the D,D

n


27/98

n Includes some type of authentication or encryption

Async>ronous Bs. Sync>ronous Communic=tions

n 7synchronous is basis of modems and dial up remote access! Must operate at same speed!

n Start and stop bits mar' the beginning and the end of each transfer!n Synchronous is +ery high speed$ go+erned by electronic cloc' timing signals!

Common D=t= Networ@ SerBices2

ies SerBices 6 Share data files and subdirectories on file ser+er

"=i SerBices 6 send and recei+e mail internally and e(ternally

Print SerBices 6 Print documents to shared printers

CientK SerBer SerBices 6 7llocate computing resources among wor'stations

Dom=in N=me SerBice 6 Matches Internet


28/98

n Difficult to tapn Resistant to &MIn ernetIf the host detects another signal while transmitting it will send a 8am signal causing all nodes to stopsending data! =odes wait to resend! Designed to a+oid collisions!

Poing 6 a primary wor'station polls another at a predetermined time to determine if it has data totransmit! Primary must gi+e permission to others to transmit!

To@en p=ssing

n To'en Ring and *DDI and 7RCnetn Cannot transmit without the to'enn &ach station can hold to'en for ma(imum predetermined amount of time

'AN Tr=nsmission "et>ods2 refer to the way pac'ets are sent on the networ' n source copied and sent to multiple destinationsn -roadcast > source copied and sent to all nodes on the networ'

'AN Topoogies iBe common topoogies2 defines the manner in which the networ' de+ices areorgani#ed to facilitate communications!)us n 7ll transmissions tra+el full length of the cable and recei+ed by all other stations!n Single point of failure in the cable!n If one of the lin's between any of the computers is bro'en$ the networ' is down!n Primarily &thernet!

n These networ's were originally designed to wor' with more sporadic traffic!

!ing n


29/98

St=r n =odes connected to a central 7= or a 8unction bo( called a hub or a concentrator at the center of the

networ'!

n 7ds: reliabilityn Ring and -us often use Star as physical connection!

Tree 6 branches can ha+e multiple nodes!

"es> 6 all nodes connected to e+ery other node!

'AN "edi= Access "et>ods 9P>ysic= =nd D=t= 'in@ '=yers:2 control the use of a networ'!Et>ernet 6 JL0!1n &thernet 6 uses CSM7ECD 6 Designed for sporadic trafficn &thernet defines a bus topology with three different cabling standards

n Thinnet 6 5L-ase0 6 coa( with segments up to 5J meters!n Thic'net 6 5L-aseS 6 coa( with segments up to LL meters!n ysic= '=yer 9#:)ridges 6 7mplify signal$ add some intelligence! 7 bridge forwards the data to all other networ' segmentsif the Media 7ccess Control 9M7C or hardware address of the destination computer is not on the localnetwor' segment! 7utomatically forwards all broadcast traffic! Does not use IP address because IP is

contained in the =etwor' ayer 91 6 D=t= 'in@ '=yer 9&:Switc>es 6 4ill only send data to the port where the destination M7C address is$ not to all ports!Primarily operate at the D=t= 'in@ '=yer 9&:protocol$ can e(amine entire pac'et!Async>ronous Tr=nsfer "ode 9AT": Switc>es 6


30/98

0AN Tec>noogies

Rules for communicating between computers on a 47=Communications between large disparate networ's!

PriB=te Circuit Tec>noogies

&+ol+ed before pac'et switching networ's! Dedicated analog or digital point>to>point connection! Serialine Internet Protocol 9SIP$ Point>to Point protocol 9PPP$ ISD=$ (DS!

n Dedicated ine 6 indefinitely and continuously reser+e for transmissions!n eased ine 6 Type of dedicated line leased from carrier!

Types and Speeds of eased ines:n Digit= Sign= 'eBe - 6 DS>L 6 single channel at FA"-ps on a T5n Digit= Sign= 'eBe # 6 DS>5 6 5!AA M-ps in 1 data at AA!1F M-ps on telephone switching networ'

n E# 6 predominately used in &urope carries data at 0!5LJ M-psn E% > predominately used in &urope carries data at 1A!1FJ M-ps

S'IP > Serial ine Internet Protocol 6 de+eloped in 5KJA to support TCPEIP o+er low speed serialinterfaces! Point>to Point protocol 6 o+er dial up and dedicated lin's$ includes login$ password$ and errorcorrection! ,perates at the Data in' ayer 90 and uses C)7P and P7P!

ISDN > Integrated Ser+ices Digital =etwor' > integration of digital telephony and data transport!Digiti#ation of the telephone networ'$ allowing +oice$ data$ etc! ,+erta'en by DS!

DS' > Digital Subscriber ine 6 uses e(isting twisted pair telephone lines!n 7DS 6 7symmetric Digital Subscriber ine more bandwidth downstream from 5! to KM-ps with upstream 5F to FAL "-ps! 7DS wor's at 5J$LLL feet lengths$ theoretical and5A$ALL practical o+er single copper twisted pair!

n SDS > Single>line 9Symmetric Digital Subscriber ine pro+ides from 5AA "-ps up to5!AA M-ps both down and up$ depending on distance$ o+er single copper twisted pair$ wor'sat 5L$LLL feet lengths!n )DS 6 )igh>Rate Digital Subscriber ine > 5!AA M-ps both down and up o+er twocopper twisted pair! Pro+ides T5 speeds! Can do 0!LAJ M-ps on three copper twisted pair!n %DS 6 %ery>high Rate Digital Subscriber ine 6 51>0 M-ps down and 5! M- to 0!1M-ps upstream o+er single copper twisted pair operating range 5$LLL 6 A$LL feet

Circuit Switc>ed Bs. P=c@et Switc>ed

Circuit Switc>ed

n Defined as a switching system in which a physical circuit path must e(ist for the duration of thetransmission

n Physical permanent connections from one point to another n ,lder technology than Pac'et Switchingn Phone companies use this a lot

1L


31/98

P=c@et Switc>ed

n Create +irtual circuits used as needed and reduce cost!n Defined as a switching system where nodes share bandwidth by sending small pac'ets!

n &ach pac'et sent to the ne(t destination by the router!n Pac'ets reassembled based on original se;uence

"ess=ge switc>ing 6 Message sent from node to node and stored at each node until forwarding path isa+ailable

P=c@et Switc>ing Tec>noogies $ V!0$ in' 7ccess Procedure -alance 97-P$ *rame Relay$ SwitchedMultimegabit Data Ser+ice 9SMDS$ 7synchronous Transfer Mode 97TM$ %oice o+er IP 9%oIP

8.&4

*irst pac'et switching networ' n Supports Switched %irtual Circuits 9S%Cs and Permanent %irtual Circuits 9P%Csn Designed to operate effecti+ely regardless of the type of systems connected ton Currently much more predominant o+erseas than in the ronous Tr=nsfer "ode 9AT":

n )igh bandwidth$ low delayn


32/98

+ig>?'eBe D=t= 'in@ Contro 9+D'C:

n Deri+ed from SDCn Specifies data encapsulation method on synchronous serial lin's

n ,perates at D=t= 'in@ '=yer 9&:

+ig> Speed Seri= Interf=ce

n Defines the electrical and physical interfaces to be used by DT&EDC&n ,perates and the P>ysic= '=yer 9#:

0AN DeBices

!outers 6 router opens pac'et and loo's at either the M7C or IP address only forwards to the networ' thatit is destined! ,perates at =etwor' ayer 91

"utipeors ? Mes 6 multi>port networ' de+ices operate at the Data in' ayer 90! Typically switch *rameRelay$ V!0 and SMDS

Access SerBers 6 pro+ides dial in and dial out access connections to a networ'! Typically asynchronous!

"odems 6 interprets digital and analog signals$ transmits o+er +oice grade telephone lines!

C>=nne SerBice Unit 9CSU:KD=t= SerBice Unit 9DSU: 6 used to terminate the physical interface on aDT& de+ice such as a terminal!

!emote Access Tec>noogies

Pro+ide remote user 9employee$ +endor$ partner access into the networ' while maintaining C!I!7!9Confidentiality$ Integrity$ 7+ailability

)enefits of !emote Access2

n Reducing costs by replacing dedicated networ' lines

n Pro+iding employees fle(ible wor' styles$ Telecommutingn -uilding efficient ties with +endors$ partners$ suppliers and employees!

!emote Access Types $ "=ny common wit> 0AN protocos.

Async>ronous Di= up Access

n )ow most people access Internetn Digital Subscriber inen


33/98

n Throughput +aries depending on number of usersn Considered insecure because local segment is not filtered or firewalled 9Says 4hoW

0ireess Tec>noogy

n *astest Growing area of connecti+ityn &ncryption is being de+elopedn JL0!55a 6 Gh# wireless > +ery soonn JL0!55b 6 0!A Gh# currently most popular up to 55 M-psn JL0!55g 6 0!A Gh# but faster than JL0!55bn 4&P 6 4ired &;ui+alency Protocol 6 up to 50J>bit 4&Pn 47P > 4ireless 7ccess Pointn SSID 6 Ser+ice Set Identifier 6 =etwor' =ame

n


34/98

n T7C7CS enabled networ' de+ice ;ueries T7C7C7 ser+er to +erify passwordn Does not support prompting for password change or use of dynamic to'ens

TACACSL Termin= Access Controer Access Contro System Pus

n Proprietary CISC, enhancementn Two factor 7uthenticationn


35/98

Dom=in 1 $ Cryptogr=p>y

Purpose of Cryptography is to protect information from being read and understood by anyone e(cept theintended recipient!

In practice encryption can be a function of time$ the effort and time re;uired for an unauthori#ed person isso large it is impractical! -y the time it is decrypted it is of little +alue!

)oc@ Cip>er 6 -rea's the plainte(t into bloc's and encrypts each with the same algorithm

Cip>er 6 Cryptographic transformation operates on the characters or bites

Cip>ertet or Cryptogram 6 unintelligible message

Custering 6 plainte(t message generates identical cipherte(t using the same algorithm but different 'eys

Codes 6 7 cryptographic transformation that operates at the word or phrase le+el

Crypt=n=ysis 6 act of obtaining plainte(t or 'ey from cipherte(t

Cryptogr=p>ic Agorit>m 6 Step>by>step procedure used to encipher plainte(t and decipher cipherte(t

Cryptogr=p>y 6 7rt and Science of hiding the meaning of communication

Cryptoogy 6 encompasses cryptography and cryptanalysis

Cryptosystem 6 set of transformations from message space to cipherte(t space

Decip>er > to undo cipherment process

Encip>er 6 to ma'e a message unintelligible to all e(cept recipient

End?to?end encryption 6 &ncrypted information that is sent from sender to recei+er

EcusiBe Or

n -oolean ,perationn Indicated by V,R

n Indicated by symbol

n &asily implemented in hardwaren LOLL$ LO55$ 5O5L$ 5O5L

Input 7 Input - ,utput T

L L L

L 5 5

5 L 5

5 5 L

n V,R operated on the bit le+eln V,R the plain te(t 9byte le+el with the 'eystream sourcen Can be re+ersed by simple V,R of output plus 'eystream!

n 7 V,R - Tn T V,R - 7

/ey $ cryptoB=ri=e

n Information or se;uence that controls enciphering and deciphering of message

1


36/98

'in@ Encryption

n &ach entity has 'ey in common with two neighboring nodes!

n =ode 5 6&ncrypts with 'ey 7n =ode 0 6 Decrypts with 'ey 7 and encrypts with 'ey -n =ode 1 6 Decrypts with "ey - and encrypts with "ey C

One time p=d

n &ncryption with 'ey " with components '5$ '0$X'n$ the encipherment uses each component of ' toencrypt message M with components m5$ m0$Xmn!

n The "ey is the same length as the Message

n "ey only used once and ne+er againn "ey must be completely randomn =ot +ery practicaln y

Traced bac' to the &gyptians in 1LLL-!C!

Scyt=e

n used by Spartans in ALL-!C! 6 wrap message around wooden doweln diameter and length are the 'eys to the cipher!

C=es=r cip>er

n Monoalphabetic substitution 6 only used one alphabet

n Specifically > In+ol+ed shifting the alphabet three lettersn "nown as C1 9Caesar shift 1 places

Cip>er Dis@s

n Two concentric dis's with letters on the edgen Can be used to match up letters

Ar=s inBented crypt=n=ysis

n 7rab philosopher al>"indi wrote Manuscript on Deciphering Cryptographic Messages

T>om=s 3efferson ? dis@s

n 5KL de+eloped de+ice with 0F dis's that could be rotated indi+iduallyn Message would assembled by lining up the dis's to the alignment bar n Then the bar was rotated a gi+en angle and the resulting letters were the cipher te(tn The angle of rotation of the alignment bar was the 'ey

Dis's used e(tensi+ely during the ci+il war

1F


37/98

UNI8 $ !OT#% shift the alphabet 51 places

+=gein "=c>ine

n De+eloped in 5K0L by -oris )agelin 6 Stoc'holm Sweden

n "nown as the M>0LK in the =rge of U.S. "I?( 9=.@.=. t>e )=c@ C>=mer:

n Crac'ed codes of a number of =ationsn Ga+e 5K00n Jn ine

n Polyalphabetic substitution cipher > using mechanical rotorsn De+eloped in 5K5K by Dutchman 7rthur Scherbius obtained ic Tec>noogiesSymmetric "ey > 9Pri+ate "ey or Secret "ey7symmetric "ey 6 9Public "ey

Public "ey cannot deri+e the pri+ate "eyPri+ate "ey Cryptography is 5$LLL times faster than public 'ey cryptography

*igenere Poy=p>=etic Cip>er

n Caesar is a subset of the %igenere Polyalphabetic Cipher n %igenere used 0F alphabetsn &ach letter of the message corresponds to a different alphabetn Sub8ect to guessing the period$ when the alphabet changes

"oduo returns t>e rem=inder oBer t>e moduo B=ueC9MOb mod =4hereC Cipher Te(tM Message- fi(ed integer = si#e of alphabet

1


38/98

Tr=nsposition $ Permut=tion

n Columnar Transposition 6 write the message +ertically and read hori#ontallyn Can be attac'ed through fre;uency analysis

*ern=m Cip>er ? ,ne time pad$ random set of non>repeating characters)oo@ or !unning /ey Cip>er

n er: &+ery V number of words within a te(t$ is a part of the real message!

Steg=nogrop>y

n )iding the e(istence of the message!n 7 digital watermar' would be used to detect copying of digital images

Secret /ey Cryptogr=p>y $ Symmetric /ey

n Sender and recei+er both 'now the 'eyn &ncrypt and decrypt with the same 'eyn Secret 'ey should be changed fre;uently

n Re;uires secure distribution of 'eys 6 by alternate channeln Ideally only used oncen Secret "ey Cryptosystem does ha+e both public and pri+ate information

n Puic

n 7lgorithm for enciphering plainte(tn Possibly some plainte(t and cipher te(tn Possibly encipherment of chosen plainte(tn PriB=te

n The "&Zn ,ne cryptographic transformation out of many possible transformations

n arge 'eys li'e 50J bit are +ery hard to brea' n %ery fastn Sender re;uires different 'ey for each recei+er

n Time stamps can be associated to the 'ey so +alid only during time window 9counters replayn =o 7uthentication or repudiationn -est 'nown is D&S de+eloped by I-M in 5KLHs for commercial use

DES $ D=t= Encryption St=nd=rd

n Deri+ed in 5K0 as deri+ation of ucifer algorithm de+eloped by )orst *iestel at I-Mn Patented in 5KA > -loc' Cipher Cryptographic Systemn Commercial and non>classified systemsn D&S describes the Data &ncryption 7lgorithm D&7n *ederal Information Processing Standard *IPS adopted D&S in 5Kn Re>certified in 5KK1 by =ational Institute of Standards and Technology but will be replaced by 7&S

7d+anced &ncryption Standard by Ri8ndael!n D&S uses FA bit bloc' si#e and F bit 'ey$ begins with FA bit 'ey and strips J parity bits

n D&7 is 5F round cryptosystem designed for implementation in hardwaren F bit 'ey 0F or L ;uadrillion possible 'eysn Distributed systems can brea' it!

n D&S uses confusion and diffusion as suggested by Claude Shannonn Confusion conceals statistical connection

n 7ccomplished through s>bo(esn Diffusion spread the influence of plainte(t character o+er many cipherte(t characters

1J


39/98

n 7ccomplished through p>bo(es

DES Oper=tes in four modes

n &lectronic Code -oo' 9&C-

n Cipher -loc' Chaining 9C-Cn Cipher *eedbac' 9C*-n ,utput *eedbac' 9,*-

Eectronic Code )oo@ n =ati+e encryption moden Pro+ides the recipe of substitutions and permutations that will be performed on the bloc' of plainte(t!n Data within a file does not ha+e to be encrypted in a certain order!

n most secure

n 7d+anced &ncryption Standardn -loc' Cipher that will replace D&S

n 7nticipated that Triple D&S will remain appro+ed for Go+ernment


40/98

Octoer &< &--- NIST Seected !ind=e

0 -elgian Cryptographers Dr! Daeman and Dr! Ri8men4ill be used by go+ernment for sensiti+e but unclassified documents

!ind=e )oc@ Cip>er

n Resistance to all 'nown attac'sn Design Simplicityn Code compactness and speed on wide +ariety of platformsn Iterati+e bloc' cipher with +ariable bloc' length and 'ey lengths that can be independently chosen as

50J$ 5K0 or 0F bits!

n 1!A ( 5L1J possible 50J bit 'ey combinations

n F!0 ( 5L possible 5K0 bit 'ey combinations

n 5!5 ( 5L possible 0F bit 'ey combinationsn Intermediate cipher result is called ?state@ that transformations operate onn Does not use *eistel transposition structure from D&Sn linear layer

n inear mi(ing layer n "ey addition layer

n Suitable for )igh Speed Chips and compact co>processor on smart cards

Twofis>

n 50J bit bloc's in 5F rounds$ up to 0F bit 'eysn De+eloped by Counterpane based on -lowfish 9also by Counterpane > -ruce Schnier n &mploys whitening before first round and after second round

n =eed to brea' whitening 'eys in addition to Twofish 'eyn Transposition

IDEA Cip>er ? International Data &ncryption 7lgorithmn FA bit bloc'$ J rounds$ and 50J bit 'eys

n ms

n De+eloped by Ronald Ri+est in 5KKAn 10$ FA or 50J bit bloc's$ up to L to 0 rounds$ L to 0LAJ bit 'eysn RS7 patented in 5KK

Puic /ey Cryptogr=p>y

n &mployee pri+ate and public 'eyn Public made a+ailable to anyone wanting to encrypt a messagen Pri+ate 'ey is used to decryptn Public "ey cannot decrypt the message it encrypted

nIdeally pri+ate 'ey cannot be deri+ed from the public 'ey

n The other can decrypt a message encrypted by one of the 'eysn Pri+ate 'ey is 'ept pri+ate

n Possible through the application of one>way functions! &asy to compute in one direction but difficultto compute the other way

n In order to be useful should ha+e a trap door$ a secret mechanism that enables you to accomplish there+erse function in a one way function

n 5$LLL to 5L$LLL times slower than secret 'ey encryptionn )ybrids use public 'ey to encrypt the symmetric 'ey

AL


41/98

n Important algorithms Diffie>)elllman RS7$ &l Gamal$ "napsac'$ &lliptic Cur+e

!SA

n Ri+est$ Shamir and 7ddleman

n -ased on difficulty of factoring a number which is the product of two large prime numbers$ may be0LL digits each!

n Can be used for &ncryption$ 'ey e(change$ and digital signatures

Diffie?+em=n

n &(change secret 'eys o+er insecure medium without e(posing 'eysn 4ithout additional session 'eyn Primarily 'ey e(change

E G=m=

n &(tended Diffie>)ellman to include signatures and encryption

"er@e?+em=n /n=ps=c@

n )a+ing set of items with fi(ed weightsn Determining which items can be added in order to obtain a gi+en total weightn Illustrated using Super increasing weights 9all weights greater than sum of pre+ious

Eiptic CurBe

n &lliptic cur+e discrete logarithm are hard to compute than general discrete logarithmn Smaller 'ey si#e same le+el of securityn &lliptic cur+e 'ey of 5FL bits RS7 of 5L0A bitsn Suited to smart cards and wireless de+ices 9less memory and processingn Digital signatures$ encryption and 'ey management

Puic /ey Cryptosystem Agorit>ms

n *actoring of arge Prime =umbers

n RS7n *inding the discrete logarithm in a finite field

n &l Gamal

n Diffie>)ellmann Shnorrs signature 7lgorithmn &lliptic Cur+en =ybergrueppels signature algorithm

Asymmetric =nd Symmetric /ey Comp=risons

7symmetric "ey Symmetric "ey

50 bits FA bits

5K0 bits 550 bits

01LA bits 50J bits

Purpose of Digit= Sign=tures

n To detect unauthori#ed modifications and to authenticate identity and non>repudiation!n Generates bloc' of data smaller than the original datan ,ne way hash functions

n ,ne way has produces fi(ed si#e output 9digestn =o two messages will ha+e same digestn ,ne way no getting original file from hash

n Message digest should be calculated using all of original files data

n 7fter message digest is calculated it is encrypted with senders pri+ate 'ey

A5


42/98

n Recei+er decrypts using senders public 'ey$ if it opens then it is from the sender!n Then recei+er computes message digest of sent file if hash is the same it has not been modified

Digit= Sign= St=nd=rd 9DSS: =nd Secure +=s> St=nd=rd 9S+S:

n &nables use of RS7 digital signature algorithm or DS7 6Digital Signature 7lgorithm 9based on &lGamal

n -oth use The Secure )ash 7lgorithm to compute message digest then processed by DS7 to +erify thesignature! Message digest is used instead of the longer message because faster!

S+A?# > Secure )ash 7lgorithm produces 5FL bit digest if message is less than 0[FA bits!n It is computationally infeasible to find message from message digestn It is computationally infeasible to find to different messages with same message digest

n Padding bits are added to message to ma'e it a multiple of 50

"D4

n De+eloped by Ronald Ri+est in 5KK5n Produces 50J bit message digest

+=s>ed "ess=ge Aut>entic=tion Code 9+"AC:

n d=y Att=c@

n Zou in a room with better than LEL chance of another person ha+ing your birthdayW =eed 01 peoplen Zou in a room with better than LEL chance of two people ha+ing the same birthdayW =eed 01 people

Cryptogr=p>ic Att=c@

)rute orce Att=c@ > try e+ery possible combination/nown P=in Tet 6 attac'er has copy of plain te(t and the associated cipherte(t of se+eral messagesC>osen P=in Tet 6 chosen plain te(t is encrypted! The attac'er has the plainte(t and cipherte(t and canchoose the plainte(t that gets encrypted!Ad=ptiBe C>osen P=in Tet 6 selection of plain te(t is altered based on pre+ious resultsCip>ertet Ony 6 only cipherte(t is 'nown! The attac'er has the cipherte(t of se+eral messages! &ach of

the messages has been encrypted using the same encryption algorithm!C>osen Cip>ertet 6 Portions of the cipher te(t are selected for trial decryption while ha+ing access to plain te(t! The attac'er can choose the cipherte(t to be decrypted and has access to the resulting decrypted plainte(t!Ad=ptiBe C>osen Cip>ertet ? Chosen cipher te(t are selected for trial decryption where selection is basedon pre+ious results)irt>d=y Att=c@ 6 the probability of two different messages ha+ing same message digest or finding twodifferent messages that ha+e the same message digest"eet in t>e "idde 6 *or attac'ing double encryption from each end and comparing in the middle"=n in t>e "idde 6 intercepting messages and forwarding on modified +ersionsDifferenti= Crypt=n=ysis 6 Pri+ate 'ey cryptography loo'ing at te(t pairs after encryption loo'ing fordifferences'ine=r Crypt=n=ysis $ using plain te(t and cipher te(t to generate a linear appro(imation of a portion of

the 'eyDifferenti= 'ine=r Crypt=n=ysis $ using both linear and differential approaches=ctoring 6 using mathematics to determine the prime factors of large numbersSt=tistic= 6 e(ploiting the lac' of randomness in 'ey generation

Puic /ey Certific=tion Systems

n 7 source could post a public 'ey under the name of another indi+idualn Digital certificates counter this attac'$ a certificate can bind indi+iduals to their 'eyn 7 Certificate 7uthority 9C7 acts as a notary to bind the 'ey to the person

A0


43/98

n C7 must be cross>certified by another C7

Puic /ey Infr=structure ? 9P/I:

Integration of digital signatures and certificates!n Digital Certificatesn Certificate 7uthorities 9C7n Registrations 7uthorities

n Policies and proceduresn Certificate Re+ocationn =on>repudiation supportn Timestampingn ightweight Directory 7ccess Protocoln Security &nabled 7pplicationsn Cross Certification

Appro=c>es to Escrowed Encryption

n 7llowing law enforcement to obtain the 'eys to +iew peoples encrypted datan &scrow the 'ey in two pieces with two trusted escrow agentsn Court order to get both piecesn Clipper Chip 6 implemented in tamper proof hardware

/ey Escrow using Puic /ey Cryptogr=p>y

n *air Cryptosystems 6 Syl+io Micali$ MITn Pri+ate 'ey is split and distributedn Can +erify each portion of the 'ey without 8oining

/ey "=n=gement

n "ey control

n "ey reco+eryn "ey storagen "ey retirementEdestructionn "ey Changen "ey Generation

n "ey theftn *re;uency of 'ey use

E?m=i Security

n =on>repudiationn Confidentiality of messagesn 7uthentication of Sourcen %erification of deli+ery

n abeling of sensiti+e materialn Control 7ccess

Secure "utipurpose Internet "=i Etensions 9SK"I"E:

n 7dds secure ser+ices to messages in MIM& formatn Pro+ides authentication through digital signaturesn *ollows Public "ey Cryptography Standards 9P"CSn


44/98

n Pro+ides fle(ibility by supporting different trust modelsn repudiation o+er IP!

AA


45/98

n Two Main Protocols aren 7uthentication )eader 6 integrity$ authentication and non>repudiationn &ncapsulating Security Payload 6 encryption$ limited authentication

n Security 7ssociation is re;uired between two parties 6 one way connection > Comprised of SecurityParameter Inde( 6 9SPI 6 10 bit identifier

n -i>directional communication re;uires two Security 7ssociations

n In %P= implementation IPSec can operate in transport or tunnel moden Tunnel mode 6 data and original IP header encrypted$ new header is addedn Transport mode 6 data encrypted$ header notn =ew header has address of %P= gatewayn MD and S)7 are used for integrity

n Security 7ssociations can be combined into bundles using either n Transport 7d8acencyn Iterated Tunneling

n I/E $ Internet /ey Ec>=nge is used for @ey m=n=gement wit> IPSEC

n I"& is set of three protocols:n Internet Security and "ey Management Protocol 9IS7"MP 6phases for establishingrelationshipn Secure "ey &(change Mechanism 6 S"&M& 6 secure e(change mechanism

n ,a'ley 6 modes of operation needed to establish secure connectionSE47= 6 Secure 47= 6 defines IPSec based widespread use of %P=s on the internet

S?+TTP 6 7lternati+e to SSn Can be used to secure indi+idual 444 Documentsn SS is session based

Secure S>e 6 SS)>0n Remote access +ia encrypted tunneln Client to ser+er authentication

n Comprised of:n Transport ayer protocoln Se+er 7uthenticationn Class 1 6 Two way client and ser+er authentication

Security Buner=iity of 0AP

n 47P G7P 6 where 4TS is decrypted and re>encrypted to SS at the 47P gateway

C>)TM is competing with 4M from 3apan

A


46/98

C>)TM is stripped down )TM$ C>)TM can be displayed on standard browser

IEEE $ (-&.## St=nd=rds

n Interface between clients and base stationn JL0!55 ayersn The physical layer P)Z can use:

n DSSS > Direct Se;uence Spread Spectrumn *) 6 *re;uency )oping Spread Spectrumn IR 6 Infrared pulse modulation

n M7C ayer 6 Medium 7ccess Controln Specifies CSM7EC7 Carrier Sense Multiple 7ccess Collision 7+oidancen Pro+ides:n Data Transfer n 7ssociation

n Re>associationn 7uthentication > 4&Pn Pri+acy > 4&Pn Power Management

AF


47/98

Dom=in 4 $ Security Arc>itecture =nd "odes

Computer Arc>itecture > ,rgani#ation of the fundamental elements comprising the computer

Main componentsn CP< 6 Central Processing metic 'ogic Unit > CP< contains 7< performs arithmetic and logical operations on binary

Computer elements connected +ia a group of conductors called the -+olatile storage where locations can be directly addressedn Data can not be altered dynamicallyn Data remains when power is lostn Some R,Ms can not be alteredn ,ther *lash type memories can be altered but slow data transfer compared to other types of memory

n &PR,MS 6 &rasable Programmable Read ,nly Memoriesn &&PR,MS 6 &lectrically &rasable Programmable Read ,nly Memories

n Infre;uent changesn 7"7 > firmware

!e= or Prim=ry "emory

n Directly addressable by the CP<n


48/98

Second=ry "emory

n =on>+olatilen Slower n &(ample Magnetic Dis's

Seuenti= "emory

n Must be searched from beginningn &(ample 6 Magnetic Tape Dri+e

*irtu= "emory

n =ses

n etc>

n CP< presents address of the instruction to memoryn Retrie+es instructions located at that address

n Eecute

n Instruction is decoded and e(ecutedn Controlled by the CP< cloc' signals

n Multi>Phase cloc' signals used for DR7Mn Single Phase cloc' signals used for SR7M

n Some instructions re;uire more than one machine cycle to e(ecuten Different States of ,peration:

n Run or operating state

n 7pplication or problem staten =on>pri+ileged instruction 6 subset of instructions for user

n Super+isory Staten Pri+ileged instructions 6 System 7dministrator may e(ecute

n 4ait State > accessing slow memory

"odern Computer En>=ncements

n Pipeining 6 increases performance by o+erlapping the steps of instructionsn Three Phases > *etch 6 Decode 6 &(ecute

n Compe Instruction Set 6 instructions perform many operations per instruction$ based on ta'ingad+antage of longer fetch times

n !educed Instruction Set ? simpler instruction that re;uire less cloc' cycles to completen Result of faster processors that enabled the fetch process to be done as ;uic'ly as decodeand &(ecute

n Sc==r Processor 6 processor that e(ecutes one instruction at a timen Supersc==r Processor 6 processor that enables concurrent e(ecution of multiple instructions in the

same pipeline

AJ


49/98

n *ery 'ong Instruction 0ord Processor $ *'I0 6 processor in which a single instruction specifiesmore than one concurrent operation

n "utiprogr=mming $ &(ecutes two or more programs simultaneously on a single processor n "utit=s@ing $ &(ecutes two or more subprograms at the same time on a single processor

n "utiprocessor 6 &(ecutes two or more programs at the same time on multiple processors

Input K Output Structures

n 7 processor communicates with outside de+ices through 9IE, interface adaptersn Comple( pro+ide

n Data bufferingn Timing and interrupt controls

n 7dapters ha+e addresses on the computer bus

n If the adapter has address in the memory space it is 'nown on memory>mapped 9IE,n -enefit is that CP< sees adapter as any other memory de+ice

Types of IKO2 n -loc' de+ices 9write bloc's of data\ hard dis'n Character de+ices 9not addressable\ 'eyboard and printer

CPU oper=ting st=tes2 ready state$ problem state$ super+isory state$ and wait state

Direct "emory Access $ D"A

Data is transferred directly to and from the memory bypassing the CP<

Interrupt Processing $ an e(ternal signal interrupts the normal program flow and re;uests ser+ice$ whenthe ser+ice is complete the CP< restores the state of the original program$ CP< can turn off interrupts

n Softw=re 6 -inary codes is machine language instructionsn Assemy '=ngu=ge > Mnemonics for basic instruction set specific to the computer

n ,ne to one relationship for each assembly instruction to each machine instruction

n Source code > assembly goes through assembler to become ob8ect 9machine coden Dis=ssemer will re+erse machine code into assemblyn "AC!OMs can be used to represent se+eral functions in assembly

n +ig> eBe =ngu=ges 6 &nglish li'e statements$ C$ 3a+a$ Pascal *,RT7=$ -7SIC

n )igh le+el code is compiled in compiler or interpreter into machine coden Compiler 6 *,RT7=$ C$ 3a+a

n Interpreter 6 3a+a$ -7SIC

Gener=tion '=ngu=ge 9G': #G' 9m=c>ine:< &G' 9=ssemy:< %?4 G' 9+ig> eBe:

n 5 G 6 machine language: Assemer 6 translates from assembly language to machine language!n 0 G 6 assembly language: Dis=ssemer 6 translates machine language to assembly!n 1 G 6 *ortran$ -7SIC$ C languages: Compier 6 translates high>le+el language to machine code!n A G 6 =7Tle+ellanguage one command at time to machine code!

Oper=ting System 9OS: 6 program or set of programs that controls the resources and operations of thecomputer

Controer ? ,S communicates with IE, through controller 9i!e! dis' controller

Open systems 6 published specifications$ sub8ect to open re+iew and e+aluation$ +ulnerabilities e(posedduring re+iew!

AK


50/98

Cosed systems 6 +endor proprietary usually not compatible with other systems$ no open re+iew$ may ha+eune(posed +ulnerabilities

Distriuted Computing

Migration from central computing to the client ser+er model$ including des'tops!Ma8or concerns:n Des'tops can contain sensiti+e information but are at ris' n


51/98

n 7ccess rights decrease as rings increase$ according to least pri+ilegen Ring system implemented by MIT in Mer Appro=c>es

n ec@ to Time of Use 6 attac' that e(ploits the difference in time between time security

applied and time that ser+ice is used

!ecoBery Procedures

n *ailure must not compromise the security of the systemn If system restart is re;uired it must re>start in safe mode 9maintenance moden "=inten=nce "ode > allows access only by pri+ileged usersn =ut Toer=nce 6 allows component of system to fail and reco+er n =i S=fe System 6 processing is halted if component of system failsn =i Soft 9resiient: 6 non critical processing is halted if component of system failsn =ioBer 6 switching to duplicate or ?hot@ bac'up

n Cod St=rt 6 when the TC- and software may be inconsistent and outside inter+ention is re;uired

Assur=nce

n Degree of confidence in satisfaction of security needs

EB=u=tion Criteri=

n Trusted Computer Security EB=u=tion Criteri= 6 9TCS&C was de+eloped in 5KJ by =ationalComputer Security Center 9=CSC

TCSEC ProBides t>e foowing2

n -asis for establishing security re;uirements in the ac;uisition specifications

5


52/98

n Standard of security ser+ices that should be pro+ided by the +endor n Means to measure trustworthiness of an information systemTCSEC is t>e Or=nge )oo@ 6 part of rainbow seriesn -asic control ob8ecti+es of ,range -oo':

n Security Policyn 7ssurancen 7ccountability

Or=nge )oo@ Addresses:n Confidentialityn NOT Integrityn It loo's specifically at the operating system and not other issues

'eBes

D 6 Minimal ProtectionC 6 Discretionary Protection 6 9C5 and C0- 6 Mandatory Protection 6 9-5$ -0$ and -17 6 %erified protection$ formal methods 975

Trusted Networ@ Interpret=tion 9TNI:$ !ed )oo@

n 7ddresses confidentiality and integrity in trusted computerEcommunications networ' systems

Trusted D=t==se "=n=gement System Interpret=tion $ 9TDI:

n 7ddresses trusted database management systems

Europe=n Inform=tion Tec>noogy Security EB=u=tion Criteri= 9ITSEC:

n 7ddresses confidentiality and integrity and a+ailabilityn Target of &+aluation 9T,& 6 system to be e+aluated

n T,& must ha+e a security target 6 including security enforcing mechanisms and security policy

n Separately e+aluates functionality and assurancen Ten *unctionality Classes > *n &ight 7ssurance e+els > .

n Se+en e+els of Correctness 6 &n &ight basic security functionsn isted as *>V$ &

&uropean ITS&C TCS&C

*>C5$ &5 C5

*>C0$ &0 C0

*>-5$ &1 -5

*>-0$ &A -0

*>-1$ & -1

*>-1$ &F 75

,ther Classes of ITS&C address high integrity and high a+ailability

Common Criteri= n TCS&C$ ITS&C and Canadian Trusted Computer Product &+aluation Criteria 9CTCP&C ha+e e+ol+ed

into one common criterian Common Criteria defines Protection Profile that specifies the security re;uirements and protections of

the product to be e+aluated!

n ,rgani#ed around TC- entitiesn Physical and logical controlsn Start up and reco+ery

0


53/98

n Reference mediationn Pri+ileged States

Certific=tion =nd Accredit=tion

n *ormal methods to ensure that appropriate safeguards are in place and functioning per thespecifications

n Must be regularly chec'ed after a defined period of time

Certific=tion 6 e+aluation of technical and non>technical security features to establish how the designmeets the security re;uirements

Accredit=tion 6 7 formal declaration by a Designated 7ppro+ing 7uthority 9D77 where a system isappro+ed to operate in a security mode

US Defense =nd GoBernment Accredit=tion =nd Certific=tion St=nd=rds

DITSCAP $ Defense Information Technology Security Certification 7ccreditation ProcessNIACAP > =ational Information 7ssurance Certification 7ccreditation Process

DITSCAP $ Defense Information Technology Security Certification 7ccreditation Process

&stablishes a standard process$ a set acti+ities$ general tas' descriptions and a management structure tocertify and accredit system will maintain its re;uired security posture!

our P>=ses of DITSCAP

n Definition 6 understanding of en+ironment and architecturen %erification 6 %erify compliance with System Security 7uthori#ation 94hile e+ol+ingn %alidation > %alidate compliance with System Security 7uthori#ation 9finaln Post 7ccreditation 6 continuing operation

NIACAP > =ational Information 7ssurance Certification 7ccreditation Processn Minimum national standards for accrediting national security system

n &stablishes a standard process$ a set acti+ities$ general tas' descriptions and a management structure tocertify and accredit system will maintain its re;uired security posture!T>ree types of NIACAP =ccredit=tion

n Site accreditation 6 e+aluates application at self contained locationn Type accreditation 6 e+aluates application at number of locationsn System accreditation > e+aluates a ma8or application or support system

Inform=tion Security "odes

n 7ccess control modelsn Integrity Modelsn Information *low Models

Access Contro "odes

7ccess Matri(Ta'e>Grant-ell>apadula Confidentiality

State Machine

Access "=tri

Straight *orward pro+ides access rights to sub8ects for ob8ects!n 7ccess Rights 6 Read$ write and e(ecuten Sub8ect 6 can be a person or a programn ,b8ects 6 file or storage de+ice

n Columns > are called 7ccess Control istsn Rows > are capability listsn Supports Discretionary 7ccess Control

1


54/98

n Tripe > Sub8ects capability is defined by a triple 9ob8ect$ rights$ random/n The random number pre+ents spoofing

T=@e?Gr=nt "ode

ree properties2

5! Simple Security Property 9ss Property 6 no reading from lower sub8ect to higher ob8ect 9=o Read


55/98

C=r@?0ison Integrity "ode

n Two eements2 well formed transaction and separation of duties.

n De+eloped in 5KJ for use in real>world commercial en+ironmentn 7ddresses the three integrity goalsn Constrained Data Item 9CDI 6 7 data Item whose integrity is to be preser+edn Integrity %erification Procedure 9I%P 6 confirms that all CDIs ha+e integrityn

Transformation Procedure 9TP 6 transforms a CDI from one integrity state to another integrity staten eories

4hen smaller systems are combined they must maintain the component system security properties

McClean 6 defined internal and e(ternal compositional constructions

n &(ternal Constructsn Cascading 6 one systems input is the output of another n *eedbac' 6 one systems output is input to another system and returned as input to thefirst systemn )oo'up 6 a system that communicates with another system and e(ternal entities

n Internal Constructs:n Intersection$


56/98

n )%? Security Dom=ins

n Trusted *acility Management 6 Identify Security 7dministrator *unctionsn Co+ert Channel 6 Co+ert Storage and Co+ert Timing Channelsn Trusted Reco+ery Re;uired

n Configuration Change Management 6 De+elopment and Maintenance

n A $ *erified Design

n A# $ *erified Design

n Trusted *acility Management 6 Identify Security 7dministrator *unctionsn Co+ert Channel 6 Co+ert Storage and Co+ert Timing Channelsn Trusted Reco+ery Re;uiredn Configuration Change Management 6 &ntire System ifecycle

&uropean ITS&C TCS&C Common Criteria

&L D &75

*>C5$ &5 C5 &70

*>C0$ &0 C0 &71

*>-5$ &1 -5 &7A

*>-0$ &A -0 &7*>-1$ & -1 &7F

*>-1$ &F 75 &7

F


57/98

Dom=in 6 $ Oper=tions Security

Tripes

n T>re=t 6 an e+ent that could cause harm by +iolating the security 9 i!e! ,perator abuse of pri+ileges

n *uner=iity 6 wea'ness in a system that enables security to be +iolated 9i!e! 4ea' Segregation ofduties

n Asset 6 anything that is a computer resource 9i!e! software data

C.I.A.

n Confidenti=ity 6 operations controls affect confidentiality of data!n Integrity 6 how well operations controls are implemented affects data integrityn AB=i=iity 6 fault tolerance and ability to reco+er

Contros =nd protections

Controls to protect hardware$ software and media from:n Threats in an operating en+ironmentn Internal and e(ternal intrudersn ,perators inappropriately accessing resources

C=tegories of Contros

n PreBent=tiBe 6 pre+ent harmful occurrencen ower amount and impact of errors entering the systemn Pre+ent unauthori#ed intruders from accessing the system

n DetectiBe 6 detect after harmful occurrencen Trac' unauthori#ed transactions

n CorrectiBe 6 restore after harmful occurrencen Data reco+ery

Addition= Contro C=tegories

n Deterrent Contro 6 encourage compliance with e(ternal controls

n Appic=tion Contros 6 designed into software applicationsn Tr=ns=ction Contros 6 control o+er the +arious stages of a transactionn Input Contros 6 ensure transactions properly input

n Processing Contros 6 guarantee transactions are proper and +alidn Output Contros 6 protect the confidentiality and integrity of outputn C>=nge Contros 6 preser+e integrity when configuration changes are maden Test Contros 6 ensure data integrity and confidentiality of data during testing

Or=nge )oo@ Contros 6 TCS&C 6 Trusted Computer Security &+aluation CriteriaAssur=nce 6 le+el of confidence that security policies ha+e been implemented correctly

Oper=tion= Assur=nce 6 focuses on basic features and architecture of a systemn System 7rchitecturen System Integrityn CoBert C>=nne An=ysis

n Trusted =ciity "=n=gement

n Trusted !ecoBery

'ife Cyce Assur=nce $ controls and standards re;uired for building and maintaining a systemn Security Testingn Design Specification and testingn Configur=tion "=n=gement

n Trusted Distribution


58/98

CoBert C>=nne An=ysis

n 7n information path that is not normally within a system and is therefore not protected by the systemsHnormal security mechanism!

n Secret ways to con+ey information to another program or person

n CoBert Stor=ge C>=nnes > con+ey information by changing stored data 9)&:

n CoBert Timing C>=nnes 6 con+ey information by altering the performance of ormodifying the timing of system resources in measurable way! 9)%< A#J Stor=ge =nd Timing:

Com=t CoBert C>=nne An=ysis ? with noise and traffic generation

Trusted =ciity "=n=gement ? Re;uired for )&< )%< =nd A#

n Defined as assignment of a specific indi+idual to administer the security of a system! 9Security7dministrator

Sep=r=tion of Duties

n 7ssign different tas's to different personneln =o single person can completely compromise a systemn Related to the concept of least pri+ileges 6 least pri+ileges re;uired to do oneHs 8ob

n Secure Systems > System 7dministrator and Security 7dministrator must be different roles!n )ighly Secure Systems > System 7dministrator$ Security 7dministrator$ and &nhanced ,perator must

be different roles!n If same person roles must be controlled and audited!

System Admin $ En>=nced Oper=tor unctions

n Installing softwaren Start up and shut down of systemn 7dding remo+ing usersn Performing bac' up and reco+ery

n )andling printers and ;ueues

Security Administr=tor unctions

n Setting user clearances$ initial passwords and other security characteristics for new usersn Changing security profiles for usersn Setting file sensiti+ity labelsn Setting security of de+icesn Renewing audit data

n )& security le+el re;uires that systems must support separate operator and system administrator roles!n )% =nd A#$ systems must clearly identify the functions of the security administrator to perform the

security>related functions!

!ot=tion of duties

imiting the length of time a person performs duties before being mo+ed

Trusted !ecoBery ? !euired for )% =nd A# eBesn &nsures Security is not breached when a system crashes or failsn System must be restarted without compromising securityn Two primary acti+ities

n *ailure Preparation 6n -ac'ups on a regular basis

n System Reco+ery >n Rebooting in single user mode 6 no other users allowed on the systemn Reco+ering all file systemsn Restoring files

J


59/98

n Reco+ering securityn Chec'ing security critical files

T>ree >ier=rc>ic= recoBery types2

n Manual Reco+ery $ Sys 7dmin must be in+ol+edn 7utomated Reco+ery 6 no inter+enti

Date post:	07-Aug-2018
Category:	Documents
Upload:	waelalysayed
View:	230 times
Download:	1 times