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Database security and privacy
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- 2. ➢Database security issues ➢Discretionaryaccess control based on grant & revoking privilege. ➢Mandatory access control and role based access ➢Control for multilevel security ➢Encryption & public key infrastructures Security and Privacy
- 3. Types of Security: ▶Legal & Ethical issues regarding the right to access certain information. ▶ System related issues such as the system levels at which various security functions should be enforced , for e.g whether a security function should be handled at the physical hardware level, the operating system level or the DBMSlevel. ▶ The need in some organizations to identify multiple security levels & to categorize the data & users based on these classifications , for e,g top secret, secret, confidential, & unclassified. ▶ Policy issues at the governmental, institutional or corporate level as to what kind of information should be made publicly available, for e.g credit ratings & personal medical records. Database Security Issues
- 4. Threats to databaseresult in loss or degradation of following security goals: ▶ Loss of Integrity: Database Integrity refers to the requirement that information be protected from improper modification. ▶ Loss of Availability: Database availability refers to making objects available to the user or a program to which they have a legitimate right. ▶ Loss of Confidentiality: Refers to the protection of data from unauthorized disclosure. ▶ Unauthorized , unanticipated or unintentional disclosure could result in loss of public confidence ▶ Modification of data includes creation, insertion , modification, changing the status of data & deletion. ▶ Integrity is lost if unauthorized changes are made to the data by either intentional or accidental acts. By:-Gourav Kottawar 4 Threats to Database
- 5. To protect databaseagainst these types of threats four countermeasures can be implemented: ▶ Access Control ▶ Flow Control ▶ Encryption ▶ Decryption By:-Gourav Kottawar 5 Threats to Database(Cont.)
- 6. In a multi-userDatabase System , DBMS must provide techniques to enable certain users or user groups to access selected portions of a database without granting access to the rest of the database. ❖ There are two types of security mechanisms: ▶ Discretionary security Mechanisms: These are used to grant privileges to users, including the capability to access specific data files, records , or fields in a specific mode (such as read, insert, delete or update) ▶ Mandatory Security Mechanisms: These are used to enforce multilevel security by classifying data & users into various security classes. ▶ Example: A role based security, which enforces policies & privileges based on the concept of roles. By:-Gourav Kottawar 6 Methods for Database Security
- 7. ▶ A majorproblem to all computer systems is that of preventing unauthorized persons from accessing the system itself. ▶ The security mechanisms of DBMS must include provisions for restricting access to the database system as a whole. ▶ The function is called Access Control & is handled by creating user accounts & passwords to control the login process by the DBMS. By:-Gourav Kottawar 7 Access Control
- 8. DBA is thecentral authority for managing a database system. DBA’s responsibilities include: ▶ Account Creation ▶ Privilege granting ▶ Privilege revocation ▶ Security level assignment Access Control (Cont.)
- 9. ▶ The typicalmethod of enforcing discretionary access control in a database system is based on the granting & revoking of privileges. Types of Discretionary Privileges: ▶ There are two levels for assigning privileges to use the database system: ◦ The account level: DBA specifies the particular privileges that each account holds independently of the relations in the database. ◦ The relation (table) level: DBA can control the privileges to access each individual relation in the database. 9 Discretionary Access Control
- 10. ▶ A userwho creates a view has precisely those privileges on the view that he or she has on the base tables used to define the view. ▶ The user creating the view must have the SELECT privilege on each underlying table ,so is always granted the SELECT privilege on the view. ▶ The creator of the view has the SELECT privilege with the grant option only if he or she has the SELECT privilege with the grant option on every underlying table. ▶ The user automatically gets the same privilege on the view. ▶ A view may be dropped as a SELECT privilege is revoked from the user who created the view. ▶ If the creator of the view gains additional privilege on the underlying tables, he or she automatically gains additional privileges on the view. By:-Gourav Kottawar 10 Grant & Revoke on views & Integrity Constraints
- 11. ◦ In thismethod a user either has or does not have a certain privilege. ◦ This approach is known as mandatory access control. ◦ It is important to note that most of the commercial DBMSs currently provide mechanisms only for discretionary access control. However the need for multilevel security exists in government, military & intelligence applications , as well as in many industrial & corporate applications. Typical security classes are: ◦ Top secret (TS) ◦ Secret (S) ◦ Confidential( C) ◦ Unclassified (U) 12 Mandatory Access Control
- 12. ▶ Subjects: Individualswho perform some activity on the database. Might include specific people or a group of users. ▶ Objects: Database units that require authorization in order to manipulate. Database units might include an entire table, specific columns in a table, specific rows in a table, etc. ▶ Actions: Any activity that might be performed on an object by a subject. For example: Read, Modify, Insert, Write, Delete, Grant . ▶ Constraint: A more specific rule regarding an aspect of the object and action. By:-Gourav Kottawar 12 Mandatory Access Control(Cont.)
- 13. ▶ RBAC emergedin 1990s as a proven technology for managing & enforcing security in large scale enterprise wide systems. ▶ Its basic notion is that permissions are associated with roles, & users are assigned to appropriate roles. ▶ Roles can be created using CREATE ROLE & DESTROY ROLE commands. ▶ RBAC appears to be a viable alternative to traditional discretionary & mandatory access controls; it ensures that only authorized users are given access to certain data or resources. ▶ User create sessions during which they may activate a subset of roles to which they belong. By:-Gourav Kottawar 13 Role Based Access Control
- 14. ▶ The previousaccess control mechanisms being strong countermeasures, may not be able to protect databases from some threats. ▶ Suppose we communicate data, but our data falls into the hands of some invalid user. ▶ In this situation , by using encryption we can disguise the message so that even if the transmission is diverted, the message will not be revealed. ▶ Encryption is a means of securing data in a insecure environment. ▶ Encryption consists of applying an encryption algorithm to data using some pre specified encryption key. ▶ The resulting data has to be decrypted using a decryption key. By:-Gourav Kottawar 14 Encryption & Public Key Infrastructure
- 15. ▶ The DES(Data Encryption Standard) is a system developed by the U.S government for use by the general public. ▶ The DES algorithm is a careful & complex combination of two of the fundamental building blocks of encryption: Substitution & Transposition ▶ The AES is a symmetric block cipher chosen by U.S government to protect classified information and is implemented in software and hardware throughout the world to encrypt data. By:-Gourav Kottawar 15 The Data & Advanced Encryption Standards
- 16. ▶ Public-key systemsare becoming popular for transmitting information via the Internet. They are extremely secure and relatively simple to use. The only difficulty with public-key systems is that you need to know the recipient's public key to encrypt a message for him or her. ▶ Private-key system are known as a secrete type of key. It is created as a part of Public-key. Public-key and Private-key are created are paired for secured communication.Such as an Email. Public-Key and Private-key
- 17. The Public keyEncryption scheme: ◦ Plain Text ◦ Encryption Algorithm ◦ Public key & Private key : Public key is used for encryption & Private key used for decryption. ◦ Cipher Text ◦ Decryption Algorithm By:-Gourav Kottawar 17 Public Key Encryption
- 18. ▶ Ciphertext (orcyphertext) is the result of encryption performed on plaintext using an algorithm, called a cipher . Ciphertext is also known as encrypted or encoded information because it contains a form of the original plaintext that is unreadable by a human or computer without the proper cipher to decrypt it. Decryption, the inverse of encryption, is the process of turning ciphertext into readable plaintext. By:-Gourav Kottawar 18 Cipher text
- 19. ▶ Plaintext isinformation a sender wishes to transmit to a receiver. Cleartext is often used as a synonym. Plaintext has reference to the operation of cryptographic algorithms, usually encryption algorithms Plaintext
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