Design of home and SME networks 14 – Data security

I am constantly amazed at the number of people (and, I must say, companies) who take a very casual attitude towards their data, rarely prioritizing any form of protection against disaster or data corruption or loss.

For an individual, it may only be a matter of years of regret if all the data on their computer is lost or destroyed, but for a business it could be the life or death of a business. Very few organizations and fewer people regularly back up their data, and even fewer do it robustly and securely.

Data loss

First of all, let’s tackle the problem of data loss and its causes:

Consider the following scenarios, which could result in data loss or corruption.

• The computer itself can be stolen or destroyed (for example, by fire)

• The data or the system disk may fail and become unreadable; this can also be due to a virus or ransomware infection.

• One or more files may be accidentally or deliberately damaged or deleted (also often by viruses or ransomware)

• A software change or user error can cause files to be accidentally encrypted or to lose encryption passwords.

Assuming there are no backups, any of the above could mean the loss of valuable, perhaps even critical, information. Many companies underestimate the losses that follow a disaster involving significant data loss by an order of magnitude – most would not survive!

For an individual, you can lose all your photos, all your family emails, all your financial records and downloaded music … While it is not life threatening, the emotional impact could be significant and the expense (both in cash as well as time) to get it back could be significant, assuming it’s possible.

The best way to minimize the impact of such a disaster is to keep backups.

What is a backup?

A backup is a copy of the files on your computer, saved on a separate medium. There are two different types:

1 Data backups, which typically do not include any of the applications required to access the data.

2 System ‘image’ backup, which includes all files on the computer’s system disk and can be used to recreate the entire system in case the computer is lost or damaged.

Data backups are typically relatively small – people are often surprised at how small they are.

System image backups, on the other hand, are usually quite large and of limited value as they can usually only be reloaded to a computer identical to the one that created them. Therefore, if you have lost your computer, the backup is of very limited use. It’s normally only used to recover after a hard drive failure – anything else and the image won’t work.

So, keep a backup of your system disk image, in case it fails, but better keep the system / application installation disks / licenses / keys so applications can be reinstalled on a new one machine.

Data backups are more versatile and can usually be easily reloaded to the same or a new computer. In many cases this will work even if the new machine has a different operating system than the old one (although there are limitations …).

However, there is an important criterion for a backup to be useful: it must be kept separate from the original data. There is little point in backing up files to a disk that is kept on or near the original computer – lose one, lose both!

Also, the backup disk should be kept disconnected from the main system, except when the backup is in progress. Why? Viruses and ransomware will affect ALL drives connected to an infected computer, making your backup unusable as well … This also applies to cloud storage: if the cloud drive is connected when the infection, it will also be infected (and, from there, any other machine that accesses the files in the cloud …)

Making a backup

So: To backup data, please connect a separate disk / pendrive or link to cloud disk, run backup program, then disconnect backup / cloud disk and store it safely. remote from the original machine (ideally in a separate building).

If you’re feeling rich enough, keep TWO backups in two different locations and update them alternately. Hopefully this will mean that at least one of them will always be available to use …