A is a sender, B a is receiver and C is attacker. When A sends data to B the attacker C can attack in 2 ways –
- Passive Attacks
- Active Attacks
As the name suggests, the nature of these attacks is “Passive”, means the attacker just tries to read/observe the data that is being send by A to B. Meaning of data is not altered in passive attacks.
Release of message content
Here the data is not modified hence it becomes difficult for A and B to know that someone is reading the data. Here data confidentiality is lost in case the data is unencrypted.
When the data from A sent to B is in a encrypted format then C the attacker cannot read the actually message unless C has key to decrypt it. In such situations C try to locate the origin of data(message), to whom the message is sent, when(time) the message is sent, what’s the size to data packets, in short the attacker try to analyze the traffic between A and B.
As the name suggests, the nature of these attacks is “Active”, means the attacker tries to corrupt/modify the original data. Attacker try to add some error bit to corrupt the data. Now here error bits are those bits that does not belong to original data. By corrupting or modifying the data either the data becomes meaningless or gets a totally different meaning.
A has a account through which he/she is sending messages to B. A is a authentic user of that respective account, but in masquerade attack C the attacker try to get access to A’s account and using A’s account credentials try log in A’s account and send messages to B. B assumes that A is sending the messages but its not A it’s C the attacker. This can take more serious turns when the resources, services and account related data is also accessed and modified by attacker. These resources, services and data officially belongs to A, but now the access of A’s account is in the hands of attacker and C can now use it for its own benefits.
When A is sending data to B. C the attacker picks the data before it reaches to B and try to induce error bits. hence the data gets modified/corrupted. The data may become meaningless or the data meaning could get changed completely. Now this corrupt data is send by C to B. Here the data integrity is lost, as the data reached to B is totally different from that of A’s original data.
Denial of Service(DoS)
When A want to access to a service, he/she will try to request a server for that specific service and server will provide the service in response to that request of A. This is the normal flow, this is how the things should work. But in DoS the attacker try to send many unnecessary/irrelevant/meaningless request packets to server making it down. Now when A will sent the service request to server it will not be able to respond to it hence called Denial of service. Here Availability of service/resource is lost.