Security Services

Question 1

service is concerned with ensuring that commucation is authentic. In the case of a single message, such as a warning or an alarm signal, the function of the authentication service is to ensure the recipient that the message is from the source that it claims to be from

Answer 1

Authentication

Question 2

is the ability to limit and control access to host systems and applications via communications links. To achieve this, each entity trying to gain access must first be identified or authenticated so that access rights can be tailored to the individual

Answer 2

Access control

Question 3

is the protection of transmitted data from passive attacks. Concerning the content of data transmission, several levels of protection can be idenfied.

Answer 3

Data confidentiality

Question 4

ensures that messages are received as sent, with no duplication, insertion, modification, reordering, or replays

Answer 4

Data integrity

Question 5

ensures that information is modified only in appropriate ways by persons authorized to change it

Answer 5

Data integrity

Question 6

prevents either a sender or a receiver from denying a transmitted message. Thus, when a message is sent, the receiver can prove that the alleged sender sent the message.

Similarly, when a message is received, the sender can prove that the alleged receiver received the message

Answer 6

Nonrepudiation

Question 7

means that a system or a system resource is accessbile and usable upon demand by an authorized system entity, according to performance specifications for the system; that is, a system is available it if provides services according to the system design whenever users request them.

Answer 7

Availability service