Simple CISSP

While FHSS created multiple channels, it only used one at a time, so it is technically not multiplexing like Orthogonal Frequency-Division Multiplexing (OFDM). Each channel used by ODFM is orthogonal (perpendicular) to the channel next to it so that they do not interfere with each other – this allows each channel to be a very narrow band. ODFM is u

AH and ESP can be used together or separately, but only ESP can provide encryption (confidentiality). When two routers want to communicate over IPSec, they must first agree on a number of options such as hashing algorithms, encryption algorithms, tunnel modes, etc. When a router receives these parameters, they are stored in a security association (

A proxy server is similar but takes it to the next level – it understands the software that is running on the computers, not just network protocols. Proxy servers often implement request caching to increase performance. A forwarding proxy allows the client to indicate which server it wishes to speak to. An open proxy is a forwarding proxy that is a

There are many software firewall packages that can run on common operating systems such as Windows and Linux. However, the more complex a system, the more vulnerabilities it will have. Because firewalls are the first line of defense, they must be extremely stable and secure from attacks. Therefore, most modern-day firewalls are implemented in appli

Sometimes a computer will send out an explorer packet to a destination that will return the path it took, and the computer will insert instructions into the packet header telling the bridge or router the exact path the frame or packet should travel. This is called source routing, and is very much frowned upon – we should let the network devices fig

If data is transmitted over baseband, then the entire channel is being used. If the channel has been split up into sub-channels, we are communicating over broadband – this allows us to send different types of data simultaneously.

If you will remember, each layer in the OSI model wraps the message from the layer above in its own envelope – this process is called data encapsulation. The resulting message from each layer has its own name. Before the message gets to the transport layer, it is simply called ‘data’. One of the strange things is that when the transport layer wraps

If any encryption algorithm is closely analyzed, weaknesses can be discovered. An algebraic attack exploits any mathematical weaknesses found in an algorithm, such as the original RSA algorithm always encrypting a ‘0’ as a ‘0’. An analytic attack looks for structural weaknesses in the algorithm, which is how 2DES was broken, and why we went from DE

Beyond creating and maintaining certificates, CAs are also responsible for revoking certificates, by adding the certificate to a certificate revocation list, or CRL. Unfortunately, browsers do not always check CRLs when setting up an SSL/TLS connection, which represents a significant security concern. The online certificate status protocol, or OCSP