CISSP Cheat Sheet Series

Domain 3: Security Engineering

Security Models and Concepts

Security Models

Security architecture frameworks
Zachman Framework
Sherwood Applied
Business Security
Architecture (SABSA)

A 2D model considering interrogations such as what, where
and when with, etc. With various views such as planner, owner,
designer etc.

- Provides access rights including discretionary access control
MATRIX
to subjects for different objects.
(Access control model) - Read, write and execute access deﬁned in ACL as matrix
columns and rows as capability lists.

To facilitate communication between stakeholders

Information Technology
Infrastructure Library Set of best practices for IT service management(ITIL)

BELL-LAPADULA(Conﬁdentiality model)

Security architecture documentation
ISO/IEC 27000 Series

Establish security controls published by Standardization (ISO)and the Electrotechnical Commission (IEC)

Control Objectives forDeﬁne goals and requirements for security controls and theInformation and Related
mapping of IT security controls to business objectives.
Technology (CobiT)
BIBA(Integrity model)

Types of security models
State Machine Models

Check each of the possible system state and ensure the proper
security relationship between objects and subjects in eachstate.

Allocate each security subject a security label deﬁning thehighest and lowest boundaries of the subject’s access to theMultilevel Lattice Models
system. Enforce controls to all objects by dividing them intolevels known as lattices.
Matrix Based Models

Arrange tables known as matrix which includes subjects andobjects deﬁning what actions subjects can take upon anotherobject.

CLARK WILSON(Integrity model)

Consider the state of the system at a point in time for a
Noninterference Models subject, it consider preventing the actions that take place at
one level which can alter the state of another level.
Information Flow Models

Try to avoid the ﬂow of information from one entity to anotherwhich can violate the security policy.

Conﬁnement

Read and Write are allowed or restricted using a speciﬁcmemory location, e.g. Sandboxing.

Data in Use

Scoping & tailoring

Security Modes
Use a single classiﬁcation level. All objects can access all
Dedicated Security Mode subjects, but users they must sign an NDA and approved priorto access on need-to-know basis
System High Security
Mode

All users get the same access level but all of them do not get
the need-to-know clearance for all the information in thesystem.

Virtualization
Guest operating systems run on virtual machines and hypervisors run on one or more
host physical machines.
Virtualization security
threats

Brewer and Nash
(A.K.A Chinese wallmodel)

Lipner Model

Memory Protection
Directly access inbuilt CPU memory to access CPU and ALU.

Stack Memory Segment Used by processors for intercommunication.

Identiﬁcation of memory locations by the processor.

Register Addressing

CPU access registry to get information.

Immediate Addressing

Part of an instruction during information supply to CPU.

Direct Addressing

Actual address of the memory location is used by CPU.

Indirect Addressing

Same as direct addressing but not the actual memory location.

Base + Offset Addressing Value stored in registry is used as based value by the CPU.

SQL Injections:

Injection / SQL Injection, Broken Authentication, Sensitive Data
Exposure, XML External Entity, Broken Access Control, Security
Misconﬁguration, Cross-Site Scripting (XSS), Insecure
Deserialization, Using Components with Known Vulnerabilities,
Insuﬃcient Logging and Monitoring
Attackers try to exploit by allowing user input to modify the
back-end/server of the web application or execute harmfulcode which includes special characters inside SQL codes
results in deleting database tables etc.

SQL Injection prevention: Validate the inputs and parameters.
Cross-Site Scripting(XSS)

Attacks carryout by inputting invalidated scripts insidewebpages.

Cross-Request Forgery

Attackers use POST/GET requests of the http web pages withHTML forms to carry out malicious activity with user accounts.
Prevention can be done by authorization user accounts to carry
the actions. Eg. using a Random string in the form, and store iton the server.

*Citation CISSP SUMMARY BY Maarten De Frankrijker

Cryptographic Terminology
Encryption

Convert data from plaintext to cipher text.

Decryption

Convert from ciphertext to plaintext.

CryptographyKey

A value used in encryption conversion process.

Synchronous

Encryption or decryption happens simultaneously.

Asynchronous

Encryption or decryption requests done subsequently or after a
waiting period.

Cryptography Goals(P.A.I.N.)• P - Privacy (Confidentiality)• A – Authentication• I - Integrity• N - Non-Repudiation.

• Conﬁdentiality• Integrity• Proof of origin• Non-repudiation• Protect data at rest
• Protect data in transit

Single private key use for encryption and decryption.

Asymmetrical

Key pair use for encrypting and decrypting. (One private andone public key)

Digital Signature

Use to verify authentication and message integrity of thesender. The message use as an input to a hash functions forvalidating user authentication.

Hash

A one-way function, convert message to a hash value used toverify message integrity by comparing sender and receivervalues.

Classical Ciphers

Substitution cipher, Transposition cipher, Caesar Cipher,
Concealment.

Digital Certiﬁcate

An electronic document that authenticate certiﬁcation owner.

Modern Ciphers

Block cipher, Stream cipher, Steganography, Combination.

Simple text message.

Ciphertext

Normal text converted to special format where it is unreadable
without reconversion using keys.

Cryptosystem

The set of components used for encryption. Includes
algorithm, key and key management functions.

Cryptanalysis

Breaking decrypting ciphertext without knowledge of
cryptosystem used.

Codes vs. Ciphers

Concealment Cipher

Cipher converts Plaintext to another written text to hide originaltext.

Substitution Ciphers

Uses a key to substitute letters or blocks of letters withdifferent letters or block of letters. I.e. One-time pad,stenography.

Transposition Ciphers

Cryptographic Algorithm Procedure of enciphers plaintext and deciphers cipher text.
Cryptography

The science of hiding the communication messages fromunauthorized recipients.

Cryptology

Cryptography + Cryptanalysis

DecipherConvert the message as readable.

EncipherConvert the message as unreadable or meaningless.

One-time pad (OTP)

Encipher all of the characters with separate unique keys.

Key Clustering

Different encryption keys generate the same plaintext
message.

Key Space

Every possible key value for a speciﬁc algorithm.

Algorithm

A mathematical function used in encryption and decryption of
data; A.K.A. cipher.

Cryptology

The science of encryption.

Transposition

Rearranging the plaintext to hide the original message; A.K.A.
Permutation.

Substitution

Exchanging or repeating characters (1 byte) in a message withanother message.

VernamKey of a random set of non-repeating characters. A.K.A. One
time pad.

Confusion

Changing a key value during each circle of the encryption.

Diffusion

Changing the location of the plaintext inside the cipher text.

Avalanche Effect

When any change in the key or plaintext signiﬁcantly change
the ciphertext.

Split Knowledge

Segregation of Duties and Dual Control.

Reorder or scramble the letters of the original message where
the key used to decide the positions to which the letters are
moved.

Common Algorithms
Symmetric/
Algorithm Asymmetric Key length

DES

Symmetric

3 DES or
TDES
Symmetric(Triple DES)

AES

IDEA

Symmetric

symmetric

64 bitBased on

Structure

64 bit cipher block size and 56 bit key
128-bitwith 8 bits parity.
Lucifer• 16 rounds of transposition andalgorithm substitution(ECB, CBC, CFB, OFB, CTR)
3 * 56 bit keys
• Slower than DES but higher security(DES EE3, DES EDE3 ,DES EEE2, DES
EDE2)

DES

128,192 or
256 bitUse 3 different bit size keys
Rijndael
Examples Bitlocker, Microsoft EFS
algorithm Fast, secure 10,12, and 14
transformation rounds
64 bit cipher blocks
each block divide to 16 smaller
blocksEach block undergo 8 rounds oftransformation
Example PGP

Skipjack

Symmetric

80 bit64 bit Block cipher

BlowﬁshSymmetric

32-448bit

64 bit Block cipher

Symmetric

128, 192,256

128 bit blocks

Work factor

The time and resources needed to break the encryption.

Nonce

Arbitrary number to provide randomness to cryptographic
function.

TwoFishBlock Cipher

Dividing plaintext into blocks and assign similar encryption
algorithm and key.

RC4

Symmetric

40-2048

Stream Cipher

Encrypt bit wise - one bit at a time with corresponding digit of
the keystream.

Example SSL and WEP• Stream cipher• 256 Rounds of transformation

RC5

Symmetric2048

Dumpster Diving

Unauthorized access a trash to ﬁnd conﬁdential information.

255 rounds transformation• 32, 64 & 128 bit block sizes

Phishing

Sending spoofed messages as originate from a trusted source.
Symmetric

CAST 128(40 to 128
bit)
CAST 256(128 to 256
bit)

Social Engineering
Script kiddie

Mislead a person to provide conﬁdential information.
A moderate level hacker that uses readily found code from theinternet.

Requirements for Hashing Message Digest
Variable length input - easy to compute - one way function - digital signatures - ﬁxed
length output

CAST

Diﬃe Hellman

MD2128-bit hash, 18 rounds of computations

MD4

128-bit hash. 3 rounds of computations, 512 bits block sizes

MD5

128-bit hash. 4 rounds of computations, 512 bits block sizes,
Merkle–Damgård construction

MD6

Variable, 0<d≤512 bits, Merkle tree structure

SHA-0

Phased out, collision found with a complexity of 2^33.6 (approx
1 hr on standard PC) Retired by NIST

SHA-1

160-bit MD, 80 rounds of computations, 512 bits block sizes,
Merkle–Damgård construction (not considered safe against
well funded attackers)

SHA-2

224, 256, 384, or 512 bits, 64 or 80 rounds of computations,
512 or 1024 bits block sizes, Merkle–Damgård construction
with Davies–Meyer compression function

RSA

Elgamal64 bit block 12 transformation rounds
128 bit block 48 rounds
transformation

Asymmetric

Asymmetric 4096 bit

Uses 1024 keys
• Public key and one-way function forencryption and digital signature
veriﬁcation• Private key and one-way function fordecryption and digital signature
generation• Used for encryption, key exchange
and digital signatures

Diﬃe Used for encryption, key exchange
Asymmetric Any key size Hellman and digital signatures
algorithm • Slower

Elliptic
Curve
Asymmetric Any key size
Cryptosystem (ECC)

Used for encryption, key exchange
and digital signatures• Speed and eﬃciency and better
security

Cryptographic Attacks
Passive Attacks

Use eavesdropping or packet sniﬃng to ﬁnd or gain access to
information.

Active Attacks

Attacker tries different methods such as message or ﬁle modiﬁcation
attempting to break encryption keys, algorithm.

Frequency
Analysis

Ciphertext-Only
AttackAn attacker uses multiple encrypted texts to ﬁnd out the key used forencryption.

Birthday Attack

Known Plaintext
AttackAn attacker uses plain text and cipher text to ﬁnd out the key used forencryption using reverse engineering or brute force encryption.

Dictionary Attacks Uses all the words in the dictionary to ﬁnd out correct key

Algebraic Attack Uses known words to ﬁnd out the keys

Chosen Plaintext An attacker sends a message to another user expecting the user will
Attackforward that message as cipher text.

Replay Attacks

Social Engineering An attacker attempts to trick users into giving their attacker try to
Attackimpersonate another user to obtain the cryptographic key used.

Analytic Attack

Assumes ﬁguring out two messages with the same hash value iseasier than message with its own hash value

An attacker uses known weaknesses of the algorithm

Statistical Attack An attacker uses known statistical weaknesses of the algorithm

Differential
Cryptanalysis

Calculate the execution times and power required by the cryptographic
device. A.K.A. Side-Channel attacks

Factoring Attack

Uses linear approximation

Password Management.
Consider all 3 CIA (integrity and availability as well as
conﬁdentiality

ITSEC
TCSEC

Explanation

D

Minimal protection

C1

DAC; Discretionary Protection (identiﬁcation, authentication,
resource protection)

C2

DAC; Controlled access protection

B1

MAC; Labeled security (process isolation, devices)

B2

MAC; Structured protection

B3

MAC; security domain

A

MAC; veriﬁed protection

Simultaneous running of
two or more programs

Multi-processing

CPU consists or morethan one processor

Processing Types
Single StateOne security level at atime.

Multi State

Multiple security levels at
a time.

Firmware

Software built in to in the
ROM.

Base Input Output
System (BIOS)

Set of instructions used toload OS by the computer.

Mobile Security
Device Encryption • Remote wiping • Remote lock out• Internal locks (voice, face recognition, pattern, pin,
password) • Application installation control • Asset
tracking (IMIE) • Mobile Device Management •Removable storage (SD CARD, Micro SD etc.)

IoT & Internet Security
Network Segmentation (Isolation) • Logical Isolation(VLAN) • Physical isolation (Network segments) •Application ﬁrewalls • Firmware updates

EAL0

Inadequate assurance

Physical Security

EAL1

Functionality tested

Internal vs external threat and mitigation

EAL2

Structurally tested

EAL3

Methodically tested and checked

EAL4

Methodically designed, tested and reviewed

EAL5

Semi-formally designed and tested

EAL6

Semi-formally verified, designed and tested

EAL7

Formally verified, designed and tested

Natural threats

ITSEC security evaluation criteria - required levels

Politicallymotivatedthreats

Minimum Protection

C1 + E1

Discretionary Protection (DAC)

C2 + E2

Controlled Access Protection (Media cleansing for reusability)

B1 + E3

Labelled Security (Labelling of data)

B2 + E4

Structured Domain (Addresses Covert channel)

B3 + E5

Security Domain (Isolation)

A + E6

Verified Protection (B3 + Dev Cycle)

Common criteria protection proﬁle components
Descriptive Elements • Rationale • Functional Requirements • Development assurance
requirements • Evaluation assurance requirements

Certiﬁcation & Accreditation
Certification

Evaluation of security and technical/non-technical features to ensure
if it meets specified requirements to achieve accreditation.

Accreditation

Declare that an IT system is approved to operate in predefinedconditions defined as a set of safety measures at given risk level.

Type Accreditation

Evaluates a system distributed in different locations.

System Accreditation

Evaluates an application system.

Site Accreditation

Evaluates the system at a specific location.

Symmetric vs. Asymmetric Encryption
Use a private key which is a secret key between two parties.
Each party needs a unique and separate private key.
Number of keys = x(x-1)/2 where x is the number of users. Eg.
DES, AES, IDEA, Skipjack, Blowﬁsh, Twoﬁsh, RC4/5/6, andCAST.

Symmetric Algorithms

Stream Based Symmetric Encryption done bitwise and use keystream generators Eg.
Cipher
RC4.
Encryption done by dividing the message into ﬁxed-length
blocks Eg. IDEA, Blowﬁsh and, RC5/6.

Block Symmetric Cipher

Use public and private key where both parties know the public
and the private key known by the owner .Public key encrypts
the message, and private key decrypts the message. 2x is total
Asymmetric Algorithms
number of keys where x is number of users. Eg. Diﬃe-Hellman,
RSA, El Gamal, ECC, Knapsack, DSA, and Zero Knowledge
Proof.
Asymmetric Algorithms

Hybrid Cryptography

Provides conﬁdentiality but
not authentication or
nonrepudiation

Provide integrity. One way
Provides conﬁdentiality,
function divides a message
integrity, authentication, andor a data ﬁle into a smaller
nonrepudiation
ﬁxed length chunks.

One key encrypts anddecrypts

One key encrypts and otherkey decrypts

Encrypted with the private
key of the sender.

Small blocks and key sizes

Message Authentication
Code (MAC) used to encrypt
the hash function with asymmetric key.

Larger key size. Bulk
encryptions

Faster and less complex. Not
Slower. More scalable.
scalable

Allows for more trade-offs
between speed, complexity,
and scalability.

Out-of-band key exchange

Hash Functions and Digital
Certiﬁcates
Hashing use message
digests.

In-band key exchange

Key Escrow and Recovery
PKI
conﬁdentiality, message integrity, authentication, and nonrepudiation

Hurricanes,
Tornadoes,
Earthquakes

Move or check location, frequency ofoccurrence, and impact. Allocate
budget.

FloodsRaised ﬂooring server rooms andoﬃces to keep computer devices .

Electrical

UPS, Onsite generators

Temperature

Explosions

Avoid areas where explosions canoccur Eg. Mining, Military training
etc.

Fire

Minimum 2 hour ﬁre rating for walls,
Fire alarms, Fire extinguishers.

Vandalism

Deploy perimeter security, double
locks, security camera etc.

Fraud/Theft

Use measures to avoid physicalaccess to critical systems. Eg.
Fingerprint scanning for doors.

Site Selection
Physicalsecurity goals

Deter Criminal Activity - Delay
Intruders - Detect Intruders - Assess
Situation - Respond to Intrusion

Site selection
issuesVisibility - External Entities Accessibility - Construction - Internal
Compartments

Server room
security• Middle of the building (Middle
ﬂoor)• Single access door or entry point• Fire detection and suppression
systems• Raised ﬂooring• Redundant power supplies• Solid /Unbreakable doors

Fences andGates

8 feet and taller with razor wire.
Remote controlled undergroundconcealed gates.

Perimeter
Intrusion
Detection
Systems

Infrared Sensors - Electromechanical
Systems - Acoustical Systems CCTV - Smart cards Fingerprint/retina scanning

Lighting
Systems

Continuous Lighting - Standby
Lighting - Movable Lighting Emergency Lighting

Media storage

Offsite media storage - redundant
backups and storage

Electricity

Faraday Cage to avoid
electromagnetic emissions - Whitenoise results in signal interference Control Zone: Faraday cage + White
noise

StaticElectricity

Use anti-static spray, mats andwristbands when handling electricalequipment - Monitor and maintainhumidity levels.

HVAC control
levelsHeat - High Humidity - Low Humidity

HVAC
Guidelines• 100F can damage storage media
such as tape drives.
• 175 F can cause computer andelectrical equipment damage.
• 350 F can result in ﬁres due topaper based products.
• HVAC: UPS, and surge protectors
to prevent electric surcharge.
• Noise: Electromagnetic
Interference (EMI), Radio Frequency
Interference
Temperatures, Humidity• Computer Rooms should have 15°
C - 23°C temperature and 40 - 60%(Humidity)

Voltage levels
control• Static Voltage• 40v can damage Circuits, 1000v
Flickering monitors, 1500v cancause loss of stored data, 2000v cancause System shut down or reboot,17000 v can cause complete
electronic circuit damage.

Sender’s Private Key - Digitally sign
Sender’s Public Key - Verify Signature

Provides authorization between the parties veriﬁed by CA.

Certiﬁcate Authority

Authority performing veriﬁcation of identities and provides
certiﬁcates.

Registration Authority

Help CA with veriﬁcation.

Certiﬁcation Path
Validation

Certiﬁcate validity from top level.

Certiﬁcation Revocation
Valid certiﬁcates list
List
Online Certiﬁcate status
Used to check certiﬁcate validity online
protocol (OCSP)
Cross-Certiﬁcation

Create a trust relationship between two CA’s

Digital Signatures• Sender’s private key used to encrypt hash value• Provides authentication, nonrepudiation, and integrity• Public key cryptography used to generate digital signatures• Users register public keys with a certiﬁcation authority (CA).
• Digital signature is generated by the user’s public key and validity period according to
the certiﬁcate issuer and digital signature algorithm identiﬁer.

Digital Certiﬁcate - Steps

Fix temperature sensors insideserver rooms , Communications Redundant internet links, mobile
communication links as a back up to
cable internet.
Man-Made Threats

Recipient's Private Key - Decrypt message

Certiﬁcates

Sabotage, vandalism, fraud, theft

Natural threat control measures

Recipient's Public Key - Encrypt message

PKI Structure

Bombs, terrorist actions, etc

Liquids, heat, gases, viruses,
Major sources
bacteria, movement: (earthquakes),
to checkradiation, etc

Phase 1: Deﬁnition • Phase 2: Veriﬁcation • Phase 3: Validation • Phase 4: Post
Accreditation

Accreditation Types

Hurricanes, tornadoes, earthquakes
ﬂoods, tsunami, ﬁre, etc

Power/utility General infrastructure damage
supply threats (electricity telecom, water, gas, etc)
Man Madethreats

D + E0Equipment
safetyFire proof Safety lockers - Access
control for locking mechanisms
such as keys and passwords.

Water leakage

Maintain raised ﬂoor and proper
drainage systems. Use of barriers
such as sand bags

Fire safety

Fire retardant materials - Fire
suppression - Hot Aisle/Cold Aisle
Containment - Fire triangle (Oxygen Heat - Fuel) - Water, CO2, Halon

Cryptography Applications & Secure Protocols

Fire extinguishers• BitLocker: Windows full volume encryption feature (Vista
Hardware -BitLocker and onward)
truecrypt• truecrypt: freeware utility for on-the-ﬂy encryption(discontinued)

Class

Type

Suppression

A

Commoncombustible

Water , SODAacid

A hardware chip installed on a motherboard used to manage
Hardware-Trusted
Symmetric and asymmetric keys, hashes, and digital
Platform Module (TPM) certiﬁcates. TPM protect passwords, encrypt drives, andmanage digital permissions.

B

LiquidCO2, HALON,
SODA acid

C

Electrical

CO2, HALON

D

Metal

Dry Powder

Link encryption
End to end encryption

Email (PGP)

Encrypts entire packet components except Data Link Control
information.
Packet routing, headers, and addresses not encrypted.
Privacy (Encrypt), Authentication (Digital signature), Integrity,(Hash) and Non-repudiation (Digital signature) Email (Secure
MIME (S/MIME): Encryption for conﬁdentiality, Hashing forintegrity, Public key certiﬁcates for authentication, andMessage Digests for nonrepudiation.

Web application

SSL/TLS. SSL encryption, authentication and integrity.

Cross-Certiﬁcation

Create a trust relationship between two CA’s

IPSEC

(Privacy, authentication, Integrity, Non Repudiation).
Tunnel mode encrypt whole packet (Secure). Transport mode
encrypt payload (Faster)

IPSEC components

Authentication Header (AH): Authentication, Integrity, Nonrepudiation. Encapsulated Security Payload (ESP): Privacy,
Authentication, and Integrity. Security Association (SA):Distinct Identiﬁer of a secure connection.

ISAKMPInternet Security Association Key Management Protocol
Authentication, use to create and manage SA, key generation.

Internet Key Exchange(IKE)

Key exchange used by IPsec .Consists of OAKLEY andInternet Security Association and Key Management Protocol(ISAKMP). IKE use Pre-Shared keys, certiﬁcates, and public key
authentication.

Wireless encryption

Wired Equivalent Privacy (WEP): 64 & 128 bit encryption. Wi-Fi
Protected Access (WPA): Uses TKIP. More secure than WEP
WPA2: Uses AES. More secure than WEP and WPA.

By using the solutions of factoring large numbers in RSA
Use a cryptographic device to decrypt the key

Multi programming

Common criteria assurance levels

Attacker sends the same data repeatedly to trick the receiver.

Try all possible patterns and combinations to ﬁnd correct key.

ReverseEngineering

Green Book

Attacker assumes substitution and transposition ciphers use repeatedpatterns in ciphertext.

Brute Force

LinearCryptanalysis

Similar to the Orange Book but addresses network security.

Enrollment - Veriﬁcation - Revocation

No conﬁdentiality, authentication, or
non-repudiation• Secure key transfer

MD Hash Algorithms

Red Book

Secret key is divided into two parts and handover to a third party.

56 bit*3

128 bit

Orange Book

A collection of criteria based on the Bell-LaPadula model used
to grade or rate the security offered by a computer systemproduct.

Simultaneous running of
two or more tasks.

Use of both Symmetric and
Use of private key which is a Use of public and private key
Asymmetric encryption. Eg.
secret key
pairs
SSL/TLS

Symmetric

Plaintext

Evaluates operating systems, application and systems. But not
network part. Consider only about conﬁdentiality. Operational
assurance requirements for TCSEC are: System Architecture,
System Integrity, Covert Channel analysis, Trusted Facility
Management and Trusted recovery.

Symmetric Algorithms• Key space = 2n. (n is number of key bits)

Use of Cryptography

Trusted Computer
System Evaluation
Criteria(TCSEC)

Multitasking

NIACAP Accreditation Process

Open-source application security project. OWASP creates
guidelines, testing procedures, and tools to use with web
security.

OWASPOWASP Top 10

Memory Addressing

Commercial mode (Conﬁdentiality and Integrity,) -BLP + Biba

Web Security

Account hijack, malware infections, data breach, loss of data
Cloud computing threats
and integrity

All of the code working in kernel mode/system.

- Use a dynamic access control based on objects previous
actions.
- Subject can write to an object if, and only if, the subject
cannot read another object in a different dataset.
- Prevents conﬂict of interests among objects.
Citation
https://ipspecialist.net/fundamental-concepts-of-security-mod
els-how-they-work/

Harrison-Ruzzo-Ullman Restricts operations able to perform on an object to a deﬁned
Model
set to preserve integrity.

Trojan infected VMs, misconﬁgured hypervisor

Monolithic Operating
System Architecture

User: An active agent• Transformation Procedure (TP): An abstract operation, suchas read, writes, and modify, implemented throughProgramming• Constrained Data Item (CDI): An item that can be manipulated
only through a TP
• Unconstrained Data Item (UDI): An item that can be
manipulated by a user via read and write operations- Enforces separation of duty
- Requires auditing- Commercial use- Data item whose integrity need to be preserved should be
audited- An integrity veriﬁcation procedure (IVP) -scans data items andconﬁrms their integrity against external threats

Graham-Denning Model Rule 1: Transfer Access, Rule 2: Grant Access, Rule 3: Delete
Objects, subjects and 8 Access, Rule 4: Read Object, Rule 5: Create Object, Rule 6:
rules
destroy Object, Rule 7: Create Subject, Rule 8: Destroy

Software as A Service (SaaS), Infrastructure As A Service
Cloud computing models(IaaS), Platform As A Service (PaaS)

Register- Cannot read data from a lower integrity level (A.K.A The
simple integrity axiom)- Cannot write data to an object at a higher integrity level.
(A.K.A the * (star) integrity axiom)- Cannot invoke service at higher integrity. (A.K.A The
invocation property)- Consider preventing information ﬂow from a low security levelto a high security level.

Information is restricted to ﬂow in the directions that are
Information ﬂow model permitted by the security policy. Thus ﬂow of information fromone security level to another. (Bell & Biba).

In addition to system high security level all the users should
Compartmented Security
have need-to-know clearance and an NDA, and formal approval
Mode
for all access required information.
Use two classiﬁcation levels as System Evaluation andMultilevel Security Mode
Assurance Levels-A subject cannot read data at a higher security level. (A.K.A
simple security rule)- Subject in a deﬁned security level cannot write to a lower
security level unless it is a trusted subject. (A.K.A *-property(star property) rule
- Access matrix speciﬁes discretionary access control.
- subject with read and write access should write and read at
the same security level (A.K.A Strong star rule :)- Tranquility prevents security level of subjects change between
levels.

Hardware architecture

System Evaluation and Assurance Levels

Water based
suppression
systems

Wet pipes - Dry Pipe - Deluge

Personnel
safety• HI VIS clothes• Safety garments /Boots• Design and Deploy an Occupant
Emergency Plan (OEP)

Internal
Security• Programmable multiple control
locks• Electronic Access Control - Digitalscanning, Sensors• Door entry cards and badges for
staff• Motion Detectors- Infrared, Heat
Based, Wave Pattern, Photoelectric,
Passive audio motion

Keymanagement

Create, distribute, transmission,storage - Automatic integration toapplication for key distribution,
storage, and handling. Backup keys
should be stored secure by
designated person only.

Testing

Pilot testing for all the backups andsafety systems to check theworking condition and to ﬁnd any
faults.