What is security , Computer Security,Network Security and attack on these security .

What is security?

Security is defined as a set of methods used for keeping your valuables safe from attackers.
Nowadays, Due to digitalization people are storing their information on the computer. They want
 to apply to keep their valuable information secure from unauthorized access.

Computer Security:)

In order to provide security on a computer, we need to understand the security
goals(we need to check the areas where attackers can hit)
1.Confidentiality
2.Integrity
3.availability

If the computer is not connected to a network then the attacker has limited options.

Attack on confidentiality: an attacker can access information by gaining authentication rights

Attack on Integrity: Can modify information only after authentication.

Attack on availability: Since the computer is not connected to the network, the only attack to availability is to create a problem in the authentication.

Network Security (Internet Security):

A broader version of computer security is known as network security,
Network security=Computer security+security measures required when
information is transferred on the network.
Now goals will remain the same but attackers may gain information by using other means also.

Network Security (Internet Security):

If a computer is connected to the network then the attacker has the following options.

Attack on confidentiality: an attacker can access information either by gaining authentication rights or by accessing information during transmission.

Attack on Integrity: Can modify information only after authentication.It can change information during communication.
Attack on availability: Since the computer is now connected to a network, the only attack on availability is to create problems in authentication both online and offline. Sometimes people on a network can not access computers due to flooding.

Attack on confidentiality: Two attacks are popular on confidentiality and both are passive attacks: An attacker can gain information either by snooping or by traffic analysis snooping: snooping refers to unauthorized access or interception of data. Traffic Analysis: Sometimes hackers can gain information by monitoring online traffic. An example is they can identify the sender and receiver address. Also, they can guess the type of communication which is taking place.

Attack on integrity:
Four types of attacks are possible:
1.Modification: After accessing or intercepting information, it has been modified.
2.Masquerading(Spoofing): In this attack, the attacker impersonates somebody else.
3.Replaying: The attacker obtains a copy of previously sent information by an authentic person and later tries to replay it.
4.Repudiation: This attack is different from others because it is related to communication parties.
Both of them may deny sending or receiving information.

Attacks on availability:
Denial of service: It is a very popular attack, can be introduced by Sending several bogus requests to the sender.
It Can also deletes server response to the client. It can block the server.