At the end of this chapter, you should be able to: Define terms related to Database Security Describe threats to data security Describe problems

DATABASE SECURITY

Learning outcomes

At the end of this chapter, you should be able to: Define terms related to Database Security Describe threats to data security Describe problems of database security and

list techniques that are used to enhance security

Understand the role of databases in Sarbanes-Oxley compliance

Database Security

Database Security: Protection of the data against accidental or intentional loss, destruction, or misuse

Increased difficulty and time consuming due to Internet access and client/server technologies

Threats to Data Security

Possible locations of data security threats


1. Accidental losses, including human error, software and hardware caused breaches

2. Theft and fraud3. Loss of privacy (personal data)4. Loss of confidentiality (corporate

data)5. Loss of data integrity6. Loss of availability (through, e.g.

sabotage)


Accidental losses, including human error, software and hardware caused breaches Establishing operating procedures

▪ User authorization▪ Uniform software installation procedures▪ Hardware maintenance schedule

Human error:▪ Some losses are inevitable, but well-thought-out

policies and procedures should reduce the amount and severity of losses


Theft and fraud Activities done by people, quite possibly

through electronic means, and may or may not alter data.

Physical security Firewall

Loss of privacy or confidentiality Loss of privacy: loss of protection of data

about individuals Loss of confidentiality: loss of protection of

critical organizational data that may have strategic value to the organization


Loss of data integrity When data integrity is compromised, data will

be invalid or corrupted Can be restored through established backup

and recovery procedures▪ Or else an organization may suffer serious losses or

make incorrect and expensive decisions Loss of availability

Sabotage of hardware, networks or applications Virus: corrupt data or software or to render the

system unusable▪ Installing antivirus▪ Update the antivirus regularly

Establishing Client/Server Security

Server security Multiple servers need to be protected

(incl. db server) Secure area Password, layers of protection against

intrusion Most DBMS database-level password

security In database server sole reliance on OS

authentication should not be encouraged

Establishing Client/Server Security

Network security Networks are susceptible to breaches of

security through:▪ Eavesdropping▪ Unauthorized connections▪ Unauthorized retrieval of packets of information

traversing the network Encryption Authentication Audit trails Routers

Application security issues in three-tier Client/Server Environments

Dynamic web page require access to the database If database is not properly protected

vulnerable to inappropriate access by any user

Privacy companies collect information on users

Application security issues in three-tier Client/Server Environments

Establishing Internet Security

Web servers, Database servers

Web Security

Static HTML files are easy to secureProtection must be established for the

HTML stored on a Web serverStandard database access controlsHTML files sensitive: placed in

directories that are protected using OS security or they may be readable but not published in the directory

Web Security

Dynamic pages are harderWeb pages stored as a template

Appropriate and current data are inserted from the database or user input once any queries associated with the page are run

Web server must be able to access database Connection usually requires full access to the database

Adequate server security is criticalDatabase server: physically secureExecution of programs on the server should be controlledUser input could embed SQL commands: needs to be

filteredAccess to data can also be controlled through user

authentication security Session security must be established TCP/IP is not a very secure protocol encryption systems

are essentialSecure Sockets Layer (SSL)

Web Security

Additional methods of Web Security:Restrict the number of users on the Web

ServerRestrict access to the Web Server:

keeping a minimum number of ports open

Remove any unneeded programs that load automatically when setting up the server

Data Privacy

Protection of individual privacy when using the Internet IMPORTANT

Rights of the individual? Individual privacy legislation:

Right to know what data have been collected To correct any errors in those data

Amount of data exchanged continues to grow: develop adequate data protection Adequate provisions to allow the data to be

used for legitimate legal purposes

Data Privacy

Individuals must guard their privacy rights and must be aware of the privacy implications of the tools they are using. E.g.: cookies

At work: communication executed through employer’s machines and networks is not private

Internet: privacy of communication is not guaranteed

Encryption, anonymous remailers and built-in security mechanisms in software help to preserve privacy

Web Privacy

W3C has created a standard, the Platform for Privacy Preferences (P3P) that will communicate a Web site’s stated privacy policies and compare that statement with the user’s own policy preferences. Addresses the following:

▪ Who is collecting the data?▪ What information is being collected and for what purpose?▪ What information will be shared with others and who are those

others?▪ Can users make changes in the way their data will be used by

the collector?▪ How are disputes resolved?▪ What policies are followed for retaining data?▪ Where can the site’s detailed policies be found, in readable

form?

Database Software Security Features

• Views or sub schemas• Integrity controls• Authorization rules• User-defined procedures• Encryption• Authentication schemes• Backup, journalizing, and

checkpointing

Views

ViewsSubset of the database that is presented to one or more usersCreated by using querying one or more of the base tablesUser can be given access privilege to view without allowing

access privilege to underlying tablesExample: Build a view that has sales by region

informationCREATE VIEW V_REGION_SALES

AS SELECT A1.region_name REGION, SUM(A2.Sales) SALES

FROM Geography A1, Store_Information A2WHERE A1.store_name = A2.store_nameGROUP BY A1.region_name

Views

store_name

Sales

Date

Los Angeles

1500 Jan-05-2008

San Diego

250 Jan-07-2008

Los Angeles

300 Jan-08-2008

Boston 700 Jan-08-2008

region_name store_name

East Boston

East New York

West Los Angeles

West San Diego

Table: Store_Information Table Geography

SELECT * FROM V_REGION_SALES

REGION

SALES

East 700

West 2050

Integrity Controls

Integrity Controls Protect data from unauthorized use Domains – set allowable values

– can be used to create a user- defined data type For example:

▪ CREATE DOMAIN money AS INTEGER (2);▪ CREATE DOMAIN order_ident AS INTEGER;▪ CREATE DOMAIN product_name AS CHAR (20);▪ CREATE DOMAIN customer_name AS CHAR (20);

Integrity Controls

Assertions enforce database conditions Checked automatically by DBMS when transactions

are run If assertion fails, DBMS generates error message E.g: Employee table has fields EmpID, EMpName,

SupervisorID, SpouseID. Company rule: no employee may supervise

his or her spouseSQL statement:

CREATE ASSERTION SpousalSupervisionCHECK (SupervisorID <> SpouseID);

Integrity Controls

Triggers prevent inappropriate actions, invoke special

handling procedures, write to log files Routines that execute in response to a

database event (INSERT, UPDATE, or DELETE)

CREATE TRIGGER STANDARD_PRICE_UPDATEAFTER UPDATE OF STANDARD_PRICE ON PRODUCT_TFOR EACH ROWINSERT INTO PRICE_UPDATES_T VALUES(PRODUCT_DESCRIPTION, DATE, STANDARD_PRICE);

Authorization Rules

Controls incorporated in the data management system

Restrict: access to data actions that people can take when they

access data Authorization matrix for:

Subjects Objects Actions Constraints

Authorization Rules

Authorization matrix

Scenario

The HR Officer is allowed to insert data into the Staff salary record however the limit of salary entry is less than RM 21,000.

The Finance Executives are allowed to Modify Staff salary record, however they are only allowed to modify the claims approval section.

A program called DX234 is allowed to read the Students Personal record with no constraints.

Authorization table for subjects (salespeople)

Authorization table for objects (orders)

Implementing authorization rules

Create an authorization rule for Inventory Records – Subjects are: Salesperson, A/C Personnel, Inventory Clerks and Carpenters

Salesperson and accounts unit may read and modify these records.

The Inventory Clerks are allowed to do all tasks except Delete.

The Carpenter may only read the records.

Authorization table for object

Oracle Privileges

Privileges at database level or table level.

INSERT and UPDATE can be granted at column level

Authorization Rules

To grant the ability to read the product table and update prices to a user with the log in ID of SMITH.

SQL statement:GRANT SELECT, UPDATE

(unit_price) ON PRODUCT_T TO SMITH

User Defined Procedures

Some DBMSs also provide capabilities for user-defined procedures to customize the authorization process

User exits or interfaces that allow system designers to define their own security procedures in addition to the authorization rules.User procedure might be designed to provide positive

user identification.For example, User might be required to supply a

procedure name in addition to a passwordValid password & correct procedure names: system calls

the procedure which asks the user a series of questions whose answers should be known only to that user.

Encryption

The coding or scrambling of data so that humans cannot read them.

Used to protect highly sensitive data such as customer credit card numbers or account balances.

Two common forms of encryption: One key: symmetric key: Data Encryption Standard (DES)

▪ Uses the same key to encrypt and decrypt▪ Easy to understand and implement

Two key: Asymmetric key▪ Different keys to encrypt and decrypt (key pair)▪ One key is published (the public key)▪ Other key is kept secret (the private key)▪ Especially popular in e-commerce applications▪ Example: SSL – provide data encryptions, server authentication, and other

services in TCP/IP connections.

Secure Sockets Layer (SSL) is a popular encryption scheme for TCP/IP connections

Basic two-key encryption

Authentication Schemes

How to identify persons who are trying to gain access to a computer or its resources?

Goal – obtain a positive identification of the user In electronic environment, user can prove by

supplying: Something the user knows: Password/PIN Something the user possesses: Smart card/token Some unique personal characteristics: biometrics

(finger print or retinal scans) Authentication schemes:

One-factor authentication Two-factor authentication Three-factor authenticationDepending on how many factors are employed


First line of defense: One-factorPasswords

Should be at least 8 characters longShould combine alphabetic and numeric

dataShould not be complete words or

personal informationShould be changed frequently


Strong AuthenticationPasswords are flawed:

Users share them with each otherThey get written down, could be copiedAutomatic logon scripts remove need to explicitly type them inUnencrypted passwords traverse a network

Possible solutions:Two factor–e.g. atm card, PINThree factor–e.g. smart card, biometric, PINBiometric devices–use of fingerprints, retinal

scans, etc. for positive IDThird-party mediated authentication–using

secret keys, digital certificates

Sarbanes-Oxley (SOX) Designed to ensure the integrity of public

companies’ financial statements. Sufficient control and security over the financial systems

and IT infrastructure Requires companies to audit the access to

sensitive data SOX audit involves in three area of control:

IT change management Logical access to data IT operations

Audit starts with a walkthrough Auditor will try to understand how the THREE areas are

handled by the IT organization

Sarbanes-Oxley (SOX): IT Change Management The process by which changes to operational

systems and databases are authorized For database, changes to: schema, database

configuration, updates to DBMS software Top deficiency found by SOX auditors:

Segregation of duties between people who had access to databases in the three common environments: development, test, production

SOX mandates: DBAs who have the ability to modify data in these environments must be different Otherwise, other personnel should be authorized to do periodic

reviews of database access by DBAs: use database audits

Sarbanes-Oxley (SOX): Logical Access to Data

Security procedures in place to prevent unauthorized access to the data

SOX perspective: Who has access to what? Who has access to too much?

Organizations must establish administrative policies and procedures

Two types of security policies and procedures: Personnel controls Physical access controls

Sarbanes-Oxley (SOX): Logical Access to Data

Personnel controls Adequate controls of personnel must be

developed and followed Hiring practices, employee monitoring,

security training, separation of duties Physical access controls

▪ Limiting access to particular areas within a building

▪ Swipe cards, equipment locking, check-out procedures, screen placement, laptop protection

Sarbanes-Oxley (SOX): IT Operations

Policies and procedures for day-to-day management of infrastructure, applications, and databases in an organization

For databases: backup, recovery, availability An area of control that helps to maintain data

quality and availability: vendor management Periodically review external maintenance

agreements for hardware and software Consider reaching agreements: organization can

get access to source code should developer go out of business or stop supporting the programs

Information in this slides were taken from Modern Database Management System, Tenth edition by Jeffrey

A.Hoffer, V.Ramesh & Heikki Topi.

END OF CHAPTER

Documents

At the end of this chapter, you should be able to: Define terms related to Database Security Describe threats to data security Describe problems