Chapter XWhen can I consider my personal

data secure?

How Important is this chapter to undestanding how computers work?

7

How Important is this chapter to understanding how to use a computer?

7 or 8

How can I be sure that my files will be available when I need them?

Data in memory is volatile. Data in storage is non-volatile so it is

always available As long as it isn’t trashed accidentally or

deliberately.

So, when using software (Word, etc.) save often.

How can I be sure that my files will be available when I need them.

BACK UP IMPORTANT DATA Often

Specifically what should YOU do with your data. At least once per semester, back up your entire

computer if it is at all convenient. I use a removable hard disk They are currently cheap

Securing YOUR data (continued) I back up my “My Documents” folder on a monthly

basis, usually burning it to a CD. My Really important stuff such as this semester’s

notes, tests, grades, etc I back up on a weekly basis to two places – another drive on my home network AND a USB flash memory drive

My really, really, really important stuff such as my financial data, I back up every time I use it to a USB flash drive and monthly to a CD.

How can I make my data secure? Secure data is data that is difficult for

OTHERS to access. There are two basic methods of securing

data: Password systems Encryption

Password Systems Username and Password – Good systems

will not tell you which one is wrong if one of them is.

Usernames are often given to you so you have no choice as to what to use.

Most people choose their own passwords.

Password Systems (Cont) Bad things users do:

Easy to guess passwords. Tell their passwords to friends. Write their passwords on a paper and leave it

near their computer. Short passwords can be guessed by brute force.

Password Systems (Cont) If the system is not secured, then the

password file may be compromised and all passwords will be unsecured.

Some systems (older versions of Windows) had their password files unencrypted.

The system manager has special powers over users, so if a system manager’s account can be cracked all security is lost.

How can you make good passwords?

Make it long. Use both letters and digits, maybe even

special symbols Use upper and lower case. Example: dsitBtitw5 (dr sidbury is the best

teacher in the world 5) Example: P=2*(L+w)

Encryption Ebub jt fodpefe tp uibu ju epfto’u mppl

opsnbm. Data is encoded so that it doesn’t look

normal.

What else can go wrong internally? Programs may make duplicate copies of

data which aren’t secure and may even be sent to developers.

Erased data is not really erased, unless you take special precautions.

What can go wrong externally? That is, what problems does the use of a

network cause? Keyboard Sniffers Wire tapping Trojan Horses Viruses Worms

Firewalls – What do they do? A firewall monitors traffic from one system

to another one. The systems may be individual computers or

networks.

Most computers which you buy have a built in firewall. You should configure them or you will not be able to use software correctly.

Firewalls Unfortunately there are lots of different

firewalls, so I can’t help you with details about them.

But we can look at some of the settings on Zone Alarm Pro, which is what I use.

Summary Data should be safe (not likely to be lost) and secure (hard for someone else to get)

Safety is primarily implemented with backups Security is implemented with:

Username/Password systems Encryption Antivirus Firewalls

Terminology Audit Trail Caesar Cipher Firewall Incremental Backup Persistent Storage Personal Identification

Number (PIN)

Public Key Encryption Transactions Trojan horses Virus Worm