Computer Data Risks
Computer data includes not only multi-media files such as data documents, images, voices that stored in file system or data base, but also hardware information, network addresses and network services, which are used to deposit and manage those information.
There are three kinds of computer data risks: data loss, data corruption and data leakage. The threats to data usually come from the followings:
- Hardware Failure
- System Crash
- Hacker / Malware Attack
- Internal Disgruntled Staff Attack
- Natural Disasters
- Loss and theft
How to Protect data effectively?
The amount of data that an average person came across daily is enormous. It is infeasible to protect all the data we are aware of. So you have to know what data are important to us and focus our resources to protect them.
-Firstly, You need to do data classification. Data of different criticality level requires different treatment in protection.
-After classification, set priorities of protection according to the criticality level, and apply proper access control to sensitive data via management and technological means.
-Employ staff to report and manage any data security issues like data loss, damage or leakage.
-If your company needs to involve a third party in data processing, e.g. involving a service provider in computer repairs, require the third party to comply with the data protection policy of your company.
Protecting data concrete measures
a) Separation or (Segregation) of data storage
Segregation (or separation) of data storage is a simple but very important.
- separate the operating systems from the data to make repairing of the system easier. (if the system fails or is compromised by hackers and malicious software, you can reinstall the operation system without affecting the data storage area)
-separate sensitive data from common data to ease the administrator applying access control to minimize the risk for data leakage.
-Storing in different servers (more secure) – applicable to business environment. For example, data of personnel department and financial department should not be stored together with data accessible by normal staff
- Storing in different hard disks – applicable to desktop computers. When the system is damaged or system disk is faulty, the system disk needs to be restored. The data (on a different disk) is not affected. If we take a broken computer to third parties for repair, take out the hard disk which stores the important data.
-Storing in different partitions – applicable to notebook computers. When system partition is crashed and is to be restored, data on a separated partition is not affected.
b) Backup
Backup refers to making copies of system, document files or database, so that when data security incident occurs, the data backup may be used to restore the original easily and instantly.
1. Backup Managements
-Backup Frequency
(schedule regular daily or weekly backups.)
-Backup Process Monitoring
(always check whether the backup process is completed successfully.)
-Assurance of the Usability of the Backup
regularly done recovery drill test to ensure that the backup data can be recovered correctly.
-label the backup media (backup date and brief content description) clearly and create an index table for backup media.
2. Backup media (sort by safety of data)
-Another HDD
-CDR and DVDR Disks
-Tape Media
-Zip Drives
-Flash Memory sticks
Storage environment for backup media
- DVDR and CDR should be kept away from direct sunlight, moisture and chemical.
- Flash drive and removable hard disk shall be kept in a dry and electrostatic free space.
c) Data recovery
Data recovery means retrieving lost, deleted, unusable or inaccessible data that lost for various reasons.
Data recovery not only restores lost files but also recovers corrupted data.
Because of different data lost reasons, there can be used different data recovery methods. There are software and hardware reasons that cause data loss, also computer data can be recovered by software and hardware.
Data recovery is using some tools to recover deleted or corrupted data. When system deletes a file, it just removes the index of the file in File Allocation Table (FAT) but leaves the data on the hard disk intact. Therefore, you can use some tools to recover the data which is deleted by accident. In the normal circumstances, data loss due to software or hardware failures can be recovered with a probability of about 85 percent. Just to remind you that if you encounter data loss, you should stop all operations immediately and do not restart the computer. Otherwise, the success rate of data recovery will decrease.
e) Permanent Deletion of Data
If you want to remove the data totally, you should overwrite all the sectors holding the old data. Standard data deletion method and programs could not always delete all data even if you use format operation .The best way is to use software which using different combinations of bit patterns to overwrite the sectors on the partition (or hdd) to ensure that the data cannot be recovered.