Security Measures In Modern Database Systems Computer Science Essay

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Securing a database is a most essential element because data must be protected from any unofficial users attaining to access. In this paper I have written a critique on database security. Further I have discussed about the access controls, discretionary, mandatory and role based access controls. Then I have talked about the internet application security procedures to secure the data.


A vast amount of information is collected in every organisation and this data is referred as the database. Dale and Lewis (2004) stated that "A database management system (DBMS) is a combination of software and data made up of the:

Physical database- a collection of files that contain the data managements systems, though, is in the ability to create tables that conceptually link various tables together."

The organisation which stores the data in the database is very important and it is like benefit to the organisation. The secrecy, integrity and availability are considered in scheming the databases.

Availability: The permission to access must be subjected to authorized users and it is meant to be compulsory. For instance if a customer wants to change details of his address or phone number he must be allowed to do so.

Integrity: The authorized users are only need to able to see all the available data. Protection of data is done from various changes. The changes in data are like creation, insertion etc. If any unofficial user makes any alteration in data then it is said integrity is gone. For example, any student can look at their grades but they are not allowed to alter them.

Secrecy: The access must be denied to the unofficial users and all the official users can view the data that is a control for accessing should be provided. For illustration, one customer bank details is not seen by another customer. To obtain the secrecy it there should be some secret protection procedures. In specific it is required to know that what data need to be secured and what data is accessed by which individual.

It is very important and essential to secure all the data in the database for an organisation. Because if the protection for data is not done all the information could be misplaced and which results in data integrity and by the use of this data may result in error decisions and inaccuracy. So any unauthorized user can even track the data of organisation which is private. To come over these types of frauds organisations use security for their data and in database security is in terms of access controls. David Ferraiolo (2003) stated that "Access control is only one aspect of a comprehensive computer security solution, but it is one of the most visible. Every time a user logs on to a multiuser computer system, access control is enforced." In the next section i have described about the three types of access controls which are available.


 Connolly and. Begg (2005) stated that "Database security encompasses hardware, software, people, and data. To effectively implement security requires appropriate controls, which are defined in specific mission objectives for the system".

Groh (2007) said that "Be sure you fully understand the access security system before distributing replicable databases containing sensitive information to its users".

Connolly and. Begg (2005) said that to maintain a good computer security everyone is responsible and specific controls are necessary for a system to reach the objectives. But Groh (2007) thought that before distributing the data to the users all the information must be secured and management need to know which data to be given to which user. For these sayings I have read and discussed about the access controls in the next section to know which the most secured system is.

Access controls

The best measure for the security in databases is using the access controls. In an organisation there are many users accessing the data and this large amounts of data needs to be protected by some incoming threats. Each and every employee has certain type of work to perform and the access to only that data is permitted and not for whole the information. Hence this is the job for database management system which permits access to some part of data. The mandatory access control, discretionary access control, role based access control are the types of access controls.

Some privileges are provided to the users and the discretionary access control is depending on these types of rights. Read, modify, insert etc can be done by the user only if some access rights are provided to him. A person who builds a table or view he automatically gets all the privileges to him as he is the owner. All the users are provided with some access rights or privileges and these privileges are maintained in a track in the database management system. And most likely repeal, the data objects are accessed by those users, who have the right to access the required privileges. The GRANT and REVOKE statements are provided in SQL and these sustain the discretionary access control. The GRANT and REVOKE statements are helpful in attainment the privileges to users and rejecting the privileges to the users respectively. One of the draw bag of discretionary access control is that any unofficial user can get the data of an official user by with any trick, moreover the data may be sensitive. Coming to the mandatory access control it is mostly dependent on the policies of the system and an individual cannot modify the policies. In mandatory access control an database object is present in which every individual is assigned a security class, security class clearance and to write or read any database object all the regulations are essential. The database objects can be write or read by the user and determined by the database management system if only the security class and clearance of security class exist. The data is accessed by all the users if there is no clearance.

Discretionary access control

Thomas, Carolyn (2005) stated that "each user is given appropriate access rights( or privileges) on specific database objects. Typically user obtains privileges when they create an object and can pass some or all of these privileges to other users at their discretion". Therefore the rights to users like which objects to access and objects not to access is determined by discretionary access control. A user can read or modify a data object by means of the privileges. For example if an individual creates an object he automatically owns all the access rights and he can able to grant some privileges to the users also.

The discretionary access control is maintained by some instructions such as GRANT and REVOKE. The GRANT is a command which is used by users to perform tasks on the tables and views. Ramakrishnan Gehrke (2003) has written syntax for the grant option is "GRANT privileges ON object TO users [with GRANT option]". In SQL not only the GRANT and REVOKE but there are various other commands like DELETE, SELECT, and INSERT etc.

INSERT: In a table created this option has an opportunity to add some columns and these columns being inserted with their values and column names.

REFERENCE: This command is used when there is a use for referencing other tables like a table can refer to other table only when there is a foreign key in the primary table.

DELETE: For instance if there is a table called object and the DELETE command is used when there is a need for deleting any row.

SELECT: if suppose an object table wants to read the data, and then this SELECT command is used. It also has option to read the columns added after by using the ALTER TABLE command.

If we consider two tables with the user A and user B, user A can grant the GRANT privilege to another user only if the GRANT option privilege is existed in the transmitting user. The complete privileges are assigned to that person who creates the table that is the owner and that is automatic; the owner has the option to grant the privileges to several users. If user generates several views it is possible that all the privileges that the base table has will be same for the created view also. Only if the user has the SELECT command, he can construct a view. Referencing a table must need a SELECT command with the GRANT option in the table which is referenced by the user. The base table must need all the privileges such as INSERT, DELETE, UPDATE, SELECT etc to send an option to the secondary tables and views which are created. Any commands such as ALTER, DROP, CREATE etc on the table is being changed by the creator of the table only and not anyone. And there is no option of GRANT or REVOKE on these commands. In relational database management systems views are considered very essential in granting the security. A view is distinct on a schema to secure the information in it in such a way that only some part of data can be viewed by the user and protect the other information. A set of clients are given some privileges to be used in SQL and they need to utilise only them. A password is requested in several systems for the data protection.

Grant and revoke privileges

Consider a user created a view and a view is said to be cancelled if there is no select privilege in table.

If the base tables are provided with some additional privileges, then a view can automatically get these privileges. The SELECT and REFERENCE privileges is very important.

There are also certain limits on the privileges which are broadcast but generally the DBMS and the SQL do not use them and the limits are called as vertical propagation limits and horizontal propagation limits. The benefit of discretionary access control is that it is used in commercial areas. The drawbacks come as it does not guarantee security to data.

Mandatory access control

The mandatory access control has been progressed in this world since there are some negative effects in discretionary access control. One of the problems with the discretionary access control is that the information in the database can be tracked by any of the unofficial persons without the permission of official person. For example if we consider that a person named tom is trying to capture the data of his head manager, he will do this in the following steps. At first, a new table is formed by tom and then the privilege INSERT is send to his manager without his knowing. Next, Tom gets some data from the base table which can be read by him and modify the data and hence the information is being tracked. Finally, there is some waiting while the file is being transferred in to the Tom table, and then Tom will undo all the changes in which he made the changes in the managers table so that this fraud is not known to the manager.

In order to avoid these types of defrauds mandatory access control is evolved. Bell-Lapadula is considered as the most proficient method in mandatory access control. Basically this form is articulated in names of rows and tables or columns and subject matter, clearances and security classes. The Bell-Lapadula enforces specially two forms of restrictions. The restrictions are called properties which are security and * property. Even the drawbacks in mandatory access control are up comed by using AMAC that is adapted mandatory access control. The security systems are there to protect the data in the database. The adapted mandatory controls have several advantages and some of them are

In a project there are many phases or stages and the adapted mandatory access control maintains all these stages.

If there is a need for mandatory security, all the segments in the database are copied into another file and they need a sustaining statement.

For a protected class of statements the function and security issue should be granted.

In the adapted access control provides all the security by means of triggers in the database.

The adapted mandatory access control has several phases and they are

Designing and constraints: If we consider a company there are various types of tasks depending on their positions and these need a range of security measures. In order to specify which tasks need what type of security the schema known as entity relationship is being illustrated. It is supposed that each and every personality has given different roles and therefore it is there term to protect all the information and they are in charge for that.

Logical design: A data model is very essential for a database management system in order to compute a conceptual schema and also in need of entity relationship which further transforms to data model. In a way to convert the entity relationship to the data model there is need of AMAC that is adapted mandatory access control. The reply for this transaction is a set of relational schemas.

The adapted mandatory access control security object:

Mechanized security labelling: In this access control all the objects which are required in the security and the subjects in the database are well precise.

Security enforcement: In this security, an object is positioned objectively and this is accessed by using a indication monitor. Security involves some trigger controls to preserve the data. Craig Mullins (2002) said that "Triggers are event-driven specialized procedures that are attached to database tables. The trigger code is automatically executed by the RDBMS as data changes in the database. Each trigger is attached to a single, specified table". The privileges INSERT, DELETE, UPDATE, READ-WRITE access are called database triggers. Every trigger is defined a detailed task in the adapted mandatory access control. To insert the latest rows or split the existing rows the INSERT trigger is widely used. To send the queries to their corresponding fragments the SELECT trigger is used. When the data is required to be protected from the unauthorized users the UPDATE and DELETE triggers are used.

Particularly in the design process and the query processing process the security is mainly used to protect the information in the database. Whenever processing a query the trigger mechanisms are preferred. Requirements analysis is carried out in adapted mandatory access control by individual group source. (C Marshall Yovits, 1994).

Role based access control:

The most recent method in securing the data is the role based access control which is introduced in early 1990's and many database management systems have implement this. The key idea is that roles are related with rights. And every user is allocated to some particular roles. The users and roles are given appropriate roles associated with them. If a person wants to define a role, the command used is CREATE ROLE and when he wants to demolish it, the command he needs to use is DROP ROLE. The Possible substitute for the standard mandatory access control and discretionary access control is the role based access control. It gives access to only authorized users to perform actions on the data. Permissions are not allocated for the users' straight forward, but they can obtain only their specific roles,

There are several advantages of RBAC some of them are: A wide range of operations can be passed out with a well managed role based access control system which is very flexible. Access can be denied by the administrators at a certain level in any disaster. Wenyang Yi (2005) said that "This is achieved by statically and dynamically regulating users' actions through the establishment and definition of roles, role hierarchies, relationships, and constraints." For instance an organisation has initiated a structure for security and is role based access control, then onwards the actions can be controlled and the actions are called granting and revoking. Granting means users can get into roles and revoking means users are out of the roles. When the latest methods are recognized role associations are formed and the old forms are deleted. By this the administrative roles are shorten and privileges can be controlled very easily, so every individual can update their roles without revising their privileges and this results them simple actions. By these brilliant characteristics surely the role based access control would be leading in the future.

Internet application security


Several methods are applicable for internet application security which involves certifying servers, encryption, and digital signatures. To a particular data or information there are two different types of encryption keys. Encryption algorithm is particular to any data and it is used to encrypt the data. There are two types of key they are user specified and dba specified key. the output for encrypted data is done using algorithm table will have in new binary form for converting the encrypted data into new version there is a decryption algorithm which help in change the encrypted data using decryption key. Junk can be created if there is no perfect decryption key then the decryption algorithm creates junk. Encryption scheme check and maintains secretly the encryption and decryption algorithms. in encrypted key there is a symmetric encryption which can also used as decrypted key the drawback of symmetric encryption is that imposter can easily know the key it's because every officer will be given key which increase the risk.

The most another popular key is public key encryption which is the well known. The decryption key can only done by owner where as official can only have encryptions key. The public key is a major one in which the encryption and decryption keys can be selected. Public key type encryption is based on one way function. It's extremely hard for computing the turnover on one way function. Public key uses RSA as the most important algorithm. In RSA finding prime and configuring is done easily where as configuring a non prime is very hard. while unique security mechanism are very fragile then to save the encrypted data algorithm tables are used, for security purpose and keep them safe by doing this there is a decrease of hack from in imposters.

One of the real time examples for encryption is: connecting a computer to wifi by utilising another computer wifi network by using Atheros card.

Background: The system designed is like a wireless network among two computers of which one computer has an internet connection. To allow the process to be simpler the computer with internet connection is adjusted so that it allows access of network to other computers also. There is an atheros card where any of Madwifi or Ndiswrapper can be used.

Solution: Instead of using network cards, the code written below is used to access the others computer network by just clicking on a button. The default network manager should necessarily to turn off, and keep the card into the mode of ad-hoc, indicate to what network to connect, to get an IP address bring the card support. The draft is as follow, the username in my case is 'valley' and the password is '12345'of ad-hoc network

To stop the default network manager we will use the commands of/etc/dbus-1/event.d/25NetworkManager stop #.

To take out the existing net card interface we will use the commands of wlanconfig ath0 destroy #.

Whenever ad-hoc mode wants to create a new net then code command used is wlanconfig ath create wlandev wifi0 wlanmode adhoc #.

To state the username of the network to join we will use the commands of iwconfig ath0 essid 'valley' #.

The command which defines the network password is iwconfig ath0 key '12345' #.

To get backing in interface we will use the commands of ifconfig ath0 up #.

The IP address is defined by using dhclient ath0 #. .

Certifying authorities

For instance, consider if there is a website named and a customer named peter wants to buy a book from this website, then peter has know about the public key of which can be known by certification authorities it is used to issue number of companies. The public key is send to VeriSign from it is a certifying authority. With the help of public key peter can send his message to through encryption. The gets the message to know it they decrypt the data which is done only by officers. By doing this peter is happy as it is only seen by staff and it not known by anyone elsewhere as there is some problem as the could not now where it is existing order or previous order. To prevent like this the administration has place a new concept known as userid and password which help to login for the users with the information. If peter want to buy a book then he has to register his detail get confirmed by the by saying that he is the member of the site. After that peter can go ahead for the second time by only giving his login id and password to the website then he can go in n search which book is required for him then select it and place that order. Peter has to place his credit or debit card number for the staff only then the staffs takes his card number and transfer the amount to their store for the book rate peter does it to believe the, if there is any falls it can be secured by electronic transaction.

Digital signatures

Consider if Kyle working in M&S request to speak Cara working for Vodafone. The communication can be done all the way through digital signatures. The public key play a major role in creating digital signatures for the data mixed up in messaging. Suppose Cara wants to send a mail to Kyle can be known through signatures that Cara has send him a mail from Vodafone. By using public key both has encrypted the data or swap the data to each other at this particular time they cannot confirm the dispatcher. There is another technique known as message signature from this there is confirmation of the user from where the mail has come but not about the message can be seen by everyone so there is a drawback for message signature in which there is no protecting to the data view.


The database systems are used expansively now days and even a small amount of data is corrupted it is a major loss for the organisation. So the developers have developed new techniques to protect the data of which the access controls proved to be the most prominent one. I have studied and written about the access controls (discretionary, mandatory and role based). The discussion about security in internet application is also been consider.