1. 1 6 Further System Fundamentals (HL) 6.4 Further Network Fundamentals

2. 6.4.4 Network Security

3. 3 Security and integrity Security = prevention of unauthorised access, theft or damage. Integrity = maintaining the accuracy of data in spite of natural causes e.g. interference, bad copying, fire damage.

4. 4 Access control Both LANs and WANs use log in and password. The user name is checked in a valid user table on the server. The password must correspond. The administrator sets access rights to different groups and individuals.

5. 5 Access control Certain folders may be invisible to certain users or visible but read only. Passwords must be secure i.e. long, random, all types of character. Biometrics are becoming more common as security measures. Good security is multifactor e.g. password, swipe card, fingerprint scan...

6. 6 Layered access Permissions allow the ranking of users ‣ e.g. student can do more than guest, ‣ teacher = teacher + student + guest, ‣ admin can do everything.

7. 7 Firewalls These are hardware/software combinations between a LAN and the outside world. They filter packets according to their source (in-bound) or destination (out- bound), preventing intrusion and access to disallowed sites and material.

8. 8 Encryption Protests data during storage and transmission. Decoding is computationally impossible without the key given a sound encryption system and a secure enough key. Asymmetric (public key) encryption is far more secure but requires more computationl