Data Security and Cryptology, III

Vulnerabilities of Information Assets. Appliable Safeguards

Data Security and Cryptology, III

Vulnerabilities of Information Assets. Appliable Safeguards

September 16th, 2015

Valdo Praust 

mois@mois.ee

Lecture Course in Estonian IT CollegeAutumn 2015 

  

September 16th, 2015

Valdo Praust 

mois@mois.ee

Lecture Course in Estonian IT CollegeAutumn 2015 

  

Components of Information Security

Infortmation security (infoturve) or data security (andmeturve) is a complex concept consisting of following three properties (security goals):• information availability (käideldavus)• information integrity (terviklus)• information confidentiality (konfidentsiaalsus)

Infortmation security (infoturve) or data security (andmeturve) is a complex concept consisting of following three properties (security goals):• information availability (käideldavus)• information integrity (terviklus)• information confidentiality (konfidentsiaalsus)

These three properties – called branches or goals of secrity – must be maintained for all information/data items we possess

Standard Model of Security Harming1. Threats (ohud) influence the data (via IT assets)

2. Threats use the vulnerabilities (nõrkused, turvaaugud) of IT assets or components of IT system

3. Threats with co-influence the vulnerabilites will determine the risk or security risk (risk, turvarisk)

4. When a certain risk realises, there will appear a security loss or security breach or security incident (turvakadu, turvarike, turvaintsident)

5. In order to minimize the risks there’s necessary to minimise vulnerabilities using safeguards of security measures (turvameetmeid)

Harming of Security

Influence of Safeguard(s)

Security and Residual Risk

Instead of absolute security usually the concept acceptable residual risk by the business process ((äriprotsessi jaoks) aktsepteeritav jääkrisk) is used

NB! It does not matter how many safeguards we implement, we never achieve the absolute security. If we implement more safeguards we only minimise the probability that security (availability, integrity of confidentiality) will be harmed but it will never fall into zero

NB! It does not matter how many safeguards we implement, we never achieve the absolute security. If we implement more safeguards we only minimise the probability that security (availability, integrity of confidentiality) will be harmed but it will never fall into zero

An acceptable residual risk is a situation where the total price of all implemented safeguards is approximately equal to the forecasted total loss of security (measured by the amount of money)

Economical View of Data Security

Peculiarities of Securing Digital Data• Cryptography is a very essential tool for achieving

both confidentiality and integrity. The metods for archiving confidentiality and integrity are completly different from the methods used in the paper document practice

• The essential part is an authentication (in a front of computer or information system) – ensuring for a technical device/entity, who is using it (which is usually followed by granting appropriate right for executing, reading, writing etc. access)

• Availability is often ensured by the network (Intrenet). Several distributed client-server systems are very wide-spread

The Role of Cryptography

This basic technique can be used:

• For ensuring the confidentiality – without the key it’s impossible to decipher the data, i.e. to get the information beared by the (encrypted) data

• For ensuring the integrity – without a special private key it’s impossible to change the data without the notice. It allows to associate the data with the certaing subjects (it also a basic principle of digital signature)

Encryption or enciphering (krüpteerimine, šifreerimine) is a technique where data are converted to the certain non-readable form. The converting process usually uses a special amount of data which are usually kept secret – a key (võti)

1. Spontaneous or accidential threats (stiihilised ohud):• environmental threats (keskkonnaohud)• technical failures and defects (tehnilised

ohud ja defektid)• human threats and failures (inimohud)

2. Deliberate acts or attacks (ründed) which are characterized by a clear intentional (human) activity (selge tahtlik (inim)tegevus)

Threats Classification by the Source

Spontaneous or Accidential Threats

Spontaneous (accidential) threats (stiihilised ohud) can be caused by:

• the force majeure (vääramatu (looduslik) jõud), which can be both occasional (lightning, flooding) or regular (wearing, material fatigue, contamination etc)

• human failures (inimvead) which can caused by inadequate skills, negligence, mis-management, environmental factors etc

Attacks

Attacks or deliberate acts (ründed) are always based on humans who make a certain intended or deliberate action (sihilik tegevus) to harm the security goals (lead by a personal interest, private or state intelligence, hooliganism etc)

Attacks or deliberate acts (ründed) are always based on humans who make a certain intended or deliberate action (sihilik tegevus) to harm the security goals (lead by a personal interest, private or state intelligence, hooliganism etc)

Attacks are usually classified by the attack sources, attacking methods and attackable objects

Sources of Attack1. Authorized users of IT systems

Available stastics show that they are the most important source. Main motives:• providing illegal (financial) profit• revenge of hired/harried people• political / ideological

2. Intelligence (economical, state-based, military etc) agents

3. Crackers, often also mis-called hackers (kräkkerid, häkkerid) an increasing factor

4. Other (in Estonia mainly criminal element)

1. Instant contact with an attackable object (IT component/device, personal, infrastrcture etc)

2. Networks (mass-used for all client-server systems). The most common attacking way (channel)

3. Portable data carriers (memory sticks etc) – were historically important but during last years are again very actual

Attack Channels

Vulnerabilities

Vulnerabilities (nõrkused ehk turvaaugud) are all such a properties of a protectable object through which (security) threats can be realised

Vulnerabilities (nõrkused ehk turvaaugud) are all such a properties of a protectable object through which (security) threats can be realised

Can be divied to:• infrastructure vulnerabilities• IT vulnerabilities• personal-related vulnerabilities• organisational vulnerabilities

Infrastructure Vulnerabilites

1. Unfavorable (physical) location of a protectable object

Increases realisation probabilities of several threats

2. Primitive or depreciated infrastructure

Doesn’t allow to implement several sefaguards (mainly physical and IT-related sefaguards)

IT(-related) Vulnerabilities• limited resources

• false installation of equipment or connection lines

• errors, defects and/or undocumented features of software (hardware)

• shortcomings of protocols (incl. communication protocols)

• shortcomings of data management

• inconvenience of safeguards (NB! Safeguards can’t heavily impair a normal work (normal availability)

Personal-related Vulnerabilities

• incorrect procedures (often due to ignorance or convenience, often systematic)

• ignorance and lack of motivation (as a rule extends to all employees of the organization)

• ignoring the safeguards (both intentionally and negligently)

Organisational Vulnerabilities• Deficiencies of work organization (rules, adapting to

new circumstances etc)• Shortcomings of resource management (computers,

communications, maintenance, testing, storage media, etc.)

• Incomplete documentation (of IT equipment, communicatimperfectnesses of safeguard selection ion lines, data storage, etc.)

• Incomplete inplementation (safeguards are implemented incorrectly, in the wrong place / configuration etc)

• Shortcomings of safeguards management (monitoring, audit etc)

Interaction Between Threats and Vulnerabilities

Main rule: threats always exploit some vulnerabilities typical to them

Main rule: threats always exploit some vulnerabilities typical to them

Information system security as a whole is weaker so far:

• the probability of threats is bigger

• there are more vulnerabilities exploitable by the threats and these vulnerabilitires are more seroius

Safeguards (Security Measures)

Safeguards (turvameetmed):

• enable to minimize vulnerabilities

• through minimizing of vulnerabilities enable to minimize the residual risk

Classification of Safeguards

• by the purpose (prevents threat, frightens attask, repairs defect etc)

• by the influented security component/goal (availability, integrity, confidentiality)

• by the type of (harmable) IT asset

• mean of implementation or realisation (procedure, technical equipment, program, building construction etc)

• by the strength of security

Safeguards (turvameetmed) can by classified differently:

Purpose of Safeguards

By porpore the safeguards are divided to:• preventive safeguards (profülaktilised

meetmed)• identifying safeguards (tuvastusmeetmed)• reconstructive safeguads (taastemeetmed)

Several safeguards are polyfunctional (for example error correcting code)

Preventive SafeguardsPreventive safeguards (profülaktilised turvameetmed) enable to prevent security incidents: • to minimize vulnerabilities• to prevent attacks• to minimize security risk probabilities• to decrease the influence of security incidents to

IT assets• to facilitate site (object) restoration

Can be divided into three categories:• reinforcable safeguards (tugevdusmeetmed)• scaring safeguards (peletusmeetmed)• separative safeguards (eraldusmeetmed)

Reinforcable Safeguards

Reinforcable safeguards (tugevdusmeetmed) will influence mainly the minimizing of security risk caused by the spontaneous threats

Reinforcable safeguards (tugevdusmeetmed) will influence mainly the minimizing of security risk caused by the spontaneous threats

Will consists of:• order or systematicness (kord)• working conditions

(töötingimused)• preventive check (ennetav

kontroll)• security awareness

(turvateadlikkus)

Examples:• internal rules• accurate job descriptions• standards• regular maintenance of infrastructure and

facilities• established procurement procedures• documentation of equipment• labeling of date carries and cables • version management • resource management• security policies, security plans, security

guidelines etc

Reinforcable Safeguards: Order

• micro-climate (temperature, humidity, air cleanliness)

• ergonomic design and layout of workplace

• corporartive social climate, positive human relations

• corporative promotion and career principles

Reinforcable Safeguards: Working Conditions

Reinforcable Safeguards: Preventive Check

• verification and testing of IT products and security mechanisms

• regular monitoring of IT security-related information

• test-attacks of safeguards and security mechanisms

• auditing of IT systems (by standard methodics)

Main branches: • suitable choosing of

employees• regular training of

employees• regular (and irrregular)

awaring events• test alarms

Reinforcable Safeguards: Sacurity Awareness

Scaring SafeguardsScaring safeguards (peletusmeetmed) minimize the probability of attacking attempts. Scaring influence is often a useful additional feature of a safeguard - the mere knowledge about safeguards often reduces the risk (especially in the cases where the expected yield for an attacker can’t compensate the risk)

Scaring safeguards (peletusmeetmed) minimize the probability of attacking attempts. Scaring influence is often a useful additional feature of a safeguard - the mere knowledge about safeguards often reduces the risk (especially in the cases where the expected yield for an attacker can’t compensate the risk)

Examples:• different sanctions (legal etc)• warning signs on documents, data carriers, gates, walls,

doors, etc.visible safeguards - a guard, a camera, illumination of the territory, security doors, card locks etc

Saparative SafeguardsSeparative safeguards (eraldusmeetmed) fend off mainly the attacks. They usually defend all aspects of security (availability, integrity, confidentiality)

Separative safeguards (eraldusmeetmed) fend off mainly the attacks. They usually defend all aspects of security (availability, integrity, confidentiality)

Can be divided into:• spatial isolation (ruumiline isoleerimine)• temporal isolation (ajaline isoleerimine)• logical isolation (loogiline isoleerimine)

Spatial Isolation• using different computers for the

data of different security levels• using different data carriers to

store the data of different security levels (with different authorized users)

• using separate lines for a data of different security levels

• using separate rooms for storing the documents of different security levels

Temporal Isolation• using a computer at different

times for a data of different level of security

• using different software at different times on the same computer

• using of (office) rooms at different times for the events of different sensitivity

Logical IsolationLogical isolation (loogiline isoleerimine) is the dividing of IT assets (for example: data) into the small elements that can be treated separately and/or grouped together

Logical isolation (loogiline isoleerimine) is the dividing of IT assets (for example: data) into the small elements that can be treated separately and/or grouped together

Realisation:• access control (password protection,

card lock etc)• service broker (eg, firewall, database

query processor)• securing (encrypting, hiding,

destroying, erasing etc)

Identifying SafeguardsBy the minimization of security loss we tend towards the following goals• avoiding the security incident• operative identifying the incident• registrating the incident (and identifying it later)• to proving the incident later

Identifying safeguards (avastavad turvameetmed) can be divided to:• operative identification (operatiivtuvastus)• post-identification (järeltuvastus)• evidence-based identification (tõendtuvastus)

Operative IdentificationOperative identification (operatiivtuvastus) involves methods which are able to identify security incidents as soon as they occur, and respond to them immediately

Operative identification (operatiivtuvastus) involves methods which are able to identify security incidents as soon as they occur, and respond to them immediately

Examples:• guard, fire and security alarm, environmental

monitoring etc• warning message caused by the blocked

(prohibited) operations, false authentication attempt etc

• debugging of software

Post-Identification

Post-identification (järeltuvastus) bases on registration of the events and proving the security incident later by them

Post-identification (järeltuvastus) bases on registration of the events and proving the security incident later by them

Examples: • logfiles of computers and lock systems• several testing and diagnostic tools• different methods of verification, auditing,

testing etc

Evidence-Based Identification

Evidence-based identification (tõendtuvastus) bases on several security elements (which are added to IT assets and data) enabling to check the integrity and/or confidentiality

Evidence-based identification (tõendtuvastus) bases on several security elements (which are added to IT assets and data) enabling to check the integrity and/or confidentiality

Examples:• parity bit, checksum, cryptographic message

digest• digital signature and timestamp• steganographic watermark • physical security elements (visible or low-

noticeable threads, seals, labels etc)

Reconstructive SafeguardsAfter a security incident there’s always necessary to restore the normal operability of a harmed object. It can be done as fast and to a greater extent as the more importance the object (IT asset) has for us

After a security incident there’s always necessary to restore the normal operability of a harmed object. It can be done as fast and to a greater extent as the more importance the object (IT asset) has for us

Main branches of reconstructive safeguards (taastavad turvameetmed) are:• backuping (varundamine)• renovation (ennistamine)• replacing (asendamine)

Backuping

Backuping (varundamine) is the main and more important premise for an any restoring

Backuping (varundamine) is the main and more important premise for an any restoring

Examples:• regular backup of data (once in a day, week

etc)• parallel (backup) computer system• RAID hard disk system

RenovationRenovation (ennistamine) involves the removing of faults, errors and defects

Renovation (ennistamine) involves the removing of faults, errors and defects

Examples:• repairing of IT equipment • repairing and modifying of software using version

management methods• repairing of infastructures (cables, power

supplies etc)• removing of malware (viruses) with anti-virus

software

Replacing

Replacing (asendamine) must be prepared for the cases of non-repairable damages

Replacing (asendamine) must be prepared for the cases of non-repairable damages

Examples:• keeping some PCs and/or laptops in

company’s stock• rapid delivery agreements of IT equipment• substituting plans of employees (for a cases

of illness, vacation, death etc)• backup office rooms (or readiness for rooms)

German BSI IT Baseline Security Method (2005, English version):

• generic aspects• infrastructure• IT systems• network• applications

Classification of Safeguards by IT Assets

ISO and Estonian National Data Security Standard EVS- ISO/IEC 13335:

• physical assets• information / data• software• ability to produce some

product or provide a service• people• intangibles

Classification of Safeguards by IT Assets

Classification of Safeguards by Realization

• organisational safeguards

• physical safeguards

• IT-related sefaguards

The most essential branch is organisational safeguards – without them any physical or IT-related sefaguards has no real influence

The most essential branch is organisational safeguards – without them any physical or IT-related sefaguards has no real influence

Organisational Safeguards

Organisational safeguards (organisatsioonilised turvameetmed) include security administration, security system design, management and security incident handling activities and operations

Organisational safeguards (organisatsioonilised turvameetmed) include security administration, security system design, management and security incident handling activities and operations

Organisational safeguards should be implemented in the first order beginning from security policy formulating, risk analysis and the security plan composing

Organisational Safeguards

... include four main components:

• activities that a certain person must do

• activities which are prohibited for a certain person

• things what happen when someone does something forbidden

• things what happen when someone doesn’t make necessary things

Physical SafeguardsPhysical safeguards (füüsilised turvameetmed) involve:

1. Infrastructure of a protectable object: • structural barriers• communications• heating and air conditioning• security doors and windows, gates etc

2. Mechanical components: locks, signs, packaging, labels etc

Usually physical safeguards involve also guards, employees of entrance building etc

IT-related SafeguardsIT-related Safeguards (infotehnilised turvameetmed) are mainly used for a performing a logical separation and an identification of a security incident

IT-related Safeguards (infotehnilised turvameetmed) are mainly used for a performing a logical separation and an identification of a security incident

Two main branches of practical tools:• software-based access control

to data and IT systems (incl. authentication techniques)

• cryptography means – for achieving of both confidentiality and integrity