Chapter 22 - Network Security

Chapter 22 - Network Security

1. Anti-virus software

   • Automatically scans all transmitted files and software copming into the network through email, attachments and portable device against a continually updating database of known viruses and then deletes any identified as malicous. A report detailing the viruses will be produced. Suspicious software may be run in isolation

2. Advantages of a standalone over a network

   • Once a virus infects one network terminial or file it can rapidly spread to others as they are all connected whereas a standalone is not

3. Firewall

   • Monitors all trafic entering and leaving the network. It blocks any messages which dont meet its security policy. Allows legit messages to pass. Part of the Proxy server. Makes a report about unautorised attempts at entry

4. Explain how access rights works

   • Authorised users access rights to data files and will be recorded in an access table. When a user attempts to modify data the user’s access rights will be checked in the access table to ensure they have EDIT/MODIFY/DELETE access and only if the user has appropriate rights will the modification be permitted

5. Auditing

   • An audit log helps identify who was responsible. It records who logged in, username, which station they logged in at, time logged in and which data files they accessed

6. Name and describe one way in which data stored on a network can be kept secure from unauthorised access

   • The use of UserIDs and passwords Each authorised user is allocated a unique UserID and a password which can be changed by the user required to log on

7. Name and describe one way in which data transmitted on a network can be kept secure from unauthorised access.

   • Data encryption. Data is encoded before being sent with a special key The reciever decodes the data using the same key. Without the key the data is meaningless