Network Security

Network Security

Danna Regan

NTC 410 Network and Telecommunications II

Mr. William Glassen

March 23, 2006

Network Security

When it comes to networking and the security of networks, there are several different methods of protecting networks. Of these differing methods, some of them sound similar, but provide differing levels of security. In the following paragraphs, I will try to explain the differences between some of the methods used.

• Explain the difference between historical and statistical logging.

Logging is a simple way of keeping a record of activity on a network. There are several types of logs that can be kept, each providing different data that can be analyzed to provide information on potential ways of improving security over time. With historical logging, records are kept of all data passing through a particular network device. This might be the gateway separating a network from the outside world or an internal router on the network. In either case, the record kept can then be analyzed at a later date and hopefully provide insight on the security of the network.

Statistical logging is a more efficient form of logging and includes some analysis already built into the report. This information might include which users were logged in during which time frames, what files were accessed, and how long they were logged in. By watching for different trends in this type of report, potentially harmful activity is more easily identifiable and mitigated.

• Explain the difference between file security and firewalls.

Firewalls provide a barrier between internal networks and the outside world. Firewalls can be used anywhere there is data transferred between two systems. Individual computers can each have their personal firewall for filtering data. Firewalls are a filtering system to determine information that is allowed and what is not allowed to pass through it. One common use of a firewall is to determine which ports can have data sent through them and to the internal network.

File security is about setting permissions for people on individual files and folders, giving some people more options than others. For some people, they may be given read-only permissions, but not the ability to write to files. This insures that users cannot overwrite or delete files. Others may have full writing and editing rights. File security protects the integrity of the files and provides version controlling on files and documents.

• Explain the difference between secret and public keys.

Encryption can be a useful deterrent in keeping sensitive information out of the hands of those not authorized and for maintaining the security of a network. Some encryption schemes utilize a secret key and a public key. Each person on the protected network has both a public and a secret key. Everyone who wants to be able to send encrypted information to another person on the network uses the public key. The recipient then uses a secret key to decrypt the information sent. A user must have a secret key to unlock the information.

• Explain the difference between symmetric and asymmetric keys.

Symmetric and asymmetric keys are very similar in their use. With symmetric keys, both the sender and the receiver use the same secret key for encryption and decryption. One of the drawbacks with symmetric keys is that if the key is compromised on one end, it is compromised on both ends.

With asymmetric keys, also known as public key encryption, the sender and the receiver each use a different key for encryption and decryption. These keys are known as the public key and a secret key. The public key is used to encrypt data, which the recipient can then decrypt