Database Protection |ENCRYPTION

ENCRYPTION

INTRODUCTION- Encryption is a technique for transforming information on a computer in such a way that it becomes unreadable.So, even if someone is able to gain access to a computer with personal data on it ,they likely won't be able to do anything with the data unless they have complicated,expensive software or the original data key.

TYPES OF ENCRYPTION- Two types of encryption are-

1. SYMMETRIC METHODS
2. ASYMMETRIC METHODS 

1. SYMMETRIC METHODS-

• Symmetric encryption is also known as private-key cryptography and is called so because the key used to encrypt and decrypt the  message must remain same..
• Using this method a sender encrypts the data with one key and then sends the data (CIPHER TEXT) and the receiver use the key to decry-pt the data. 

2. ASYMMETRIC METHODS- 

• Asymmetric method or public key cryptography is different than the previous method because it uses two keys for encryption or decryption
• .A public key is freely available to everyone and is used to encrypt messages and a different private key is used by the recipient to decry-pt messages.

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Database Protection | firewalls

FIREWALLS

INTRODUCTION-

• The term firewall originally referred to a wall intended to confine a fire or potential fire within a building. Later uses refer to similar structures, such as the metal sheet separating the engine compartment of a vehicle or aircraft from the passenger compartment.
• In computing, a firewall is a software or hardware-based network security system that controls the incoming and outgoing network traffic based on applied rule set. 
• A firewall establishes a barrier between a trusted, secure internal network and another network (e.g., the Internet) that is not assumed to be secure and trusted.
• Many personal computer operating systems include software-based firewalls to protect against threats from the public Internet.
•  Many routers that pass data between networks contain firewall components and, conversely, many firewalls can perform basic routing functions.

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Database Protection | digital signatures

DIGITAL SIGNATURES

AT SENDER SIDE

• Message is divided into two parts.Firstly through hash function message digest is made.Message digest is the smallest version of the message.
• Secondly the message is encrypted i.e. cipher text is made and then the combination of both i.e. encrypted  message + message digest is sent to the receiver.

AT RECEIVER SIDE

• At receiver side through hash function a new message digest is made and also through decryption method.
• If both the message digest are same then we can say that the received message is correct or without error.

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Database management system | DOMAIN KEY NORMAL FORM

DOMAIN KEY NORMAL FORM

• Domain/key normal form (DKNF) is a normal form used in database normalization which requires that the database contains no constraints other than domain constraints and key constraints.

• A domain constraint specifies the permissible values for a given attribute, while a key constraint specifies the attributes that uniquely identify a row in a given table.

• The domain/key normal form is achieved when every constraint on the relation is a logical consequence of the definition of keys and domains, and enforcing key and domain restraints and conditions causes all constraints to be met. Thus, it avoids all non-temporal anomalies.

• The reason to use domain/key normal form is to avoid having general constraints in the database.

• Most databases can easily test domain and key constraints on attributes. General constraints however would normally require special database programming in the form of stored procedures that are expensive to maintain and expensive for the database to execute. Therefore general constraints are split into domain and key constraints.

• It's much easier to build a database in domain/key normal form .

• While the domain/key normal form eliminates the problems found in most databases, it tends to be the most costly normal form to achieve. 

• The third normal form, Boyce–Codd normal form, fourth normal form and fifth normal form are special cases of the domain/key normal form. All have either functional, multi-valued or join dependencies that can be converted into (super)keys. 

• The domains on those normal forms were unconstrained so all domain constraints are satisfied. However, transforming a higher normal form into domain/key normal form is not always a dependency-preserving transformation and therefore not always possible.

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Database management software microsoft access | download microsoft access

Microsoft Access, also known as Microsoft Office Access, is a database management system from Microsoft that combines the relational Microsoft Jet Database Engine with a graphical user interface and software-development tools. It is a member of the Microsoft Office suite of applications, included in the Professional and higher editions or sold separately.

Microsoft Access stores data in its own format based on the Access Jet Database Engine. It can also import or link directly to data stored in other applications and databases.

Software developers and data architects can use Microsoft Access to develop application software, and "power users" can use it to build software applications. Like other Office applications, Access is supported by Visual Basic for Applications, an object-oriented programming language that can reference a variety of objects including DAO (Data Access Objects), ActiveX Data Objects, and many other ActiveX components. Visual objects used in forms and reports expose their methods and properties in the VBA programming environment, and VBA code modules may declare and call Windows operating-system functions.

you can download microsoft access here.
download link:click here

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