Does a VPN use link encryption or end-to-end?
In the majority of cases, a VPN uses link encryption as the data encryption between the VPN client and the VPN server. The end-to-end encryption is the more complex process that can be discussed as the data encryption between the client application and the server provided with the help of additional technologies.
Does a VPN use symmetric or asymmetric encryption?
VPNs use both symmetric and asymmetric forms of cryptography for encryption. There are some differences in the usage of these types. Symmetric cryptography can utilize one key for both the processes of encryption and decryption and can be considered as more efficient in using for protecting the definite data. It is typical for asymmetric cryptography to use different keys for encryption and decryption, and it is used for authentication.
Does a PKI perform encryption?
According to its functions and peculiarities, a PKI can perform encryption, but the process is limited by the fact a PKI can perform only one action effectively at a time and, it is rather difficult to perform, for instance, the full authentication and encryption. That is why a PKI can perform encryption, but it is not used for continuous mutual authentication.
Does a PKI use symmetric or asymmetric encryption?
A PKI uses asymmetric encryption based on the key pair. Thus, both keys are necessary for the realization of the processes of encrypting and decrypting. The asymmetric encryption is also used because PKI usually works with public and private keys.
Firewalls are targets for penetrators. Why are there few compromises of firewalls?
The firewalls are controlled and protected with the help of passwords. Nevertheless, there are few compromises. The modern and developed firewalls continue to protect the network even if the system is attacked, and a firewall is compromised.
Suppose you are a customs inspector. You are responsible for checking suitcases for secret compartments in which bulky items such as jewelry might be hidden. Describe the procedure you would follow to check for the compartments.
It is necessary to check suitcases with the help of a scanner to observe the hidden items. If there are no possibilities to use the scanner or an inspector have some doubts, it is possible to check the exterior characteristics of the suitcase, to open it before the owner and check the obvious large and small compartments about the double sides or bottoms with paying much attention to the thickness of the material and its qualities.
Your boss hands you a microprocessor and its technical reference manual. You are asked to check for undocumented features of the processor. Because of the number of possibilities, you cannot test every operation code with every combination of operands. Outline the strategy you would use to identify and characterize unpublicized operations.
It is possible to examine the documented operations and features of the processor carefully without paying much attention to their effects. The expected number of operands can be used for testing the possible combinations of the operations and for testing the unexpected operands and effects. The test of a few unexpected operands can provide a picture of the possible undocumented operations.
Your boss hands you a computer program and its technical reference manual. You are asked to check for undocumented features of the program. How is this activity similar to the task of the previous exercises? How does it differ? Which is the most feasible? Why?
There are several ways to test computer programs, and this fact provides us with the opportunity to use more methods in comparison with the previous task. This variability is the main difference between the first task and this one. The undocumented features of the program can be tested with the help of using such approaches as white box testing and black box testing which are widely utilized for testing software with references to the program source and binary codes. Thus, this test can be discussed as more feasible.