Backups and data recovery

Read here about different types of backups, data recovery and biometrics

Last edited: December 7th, 2020.

Table of contents:

1.Backups and intro to Data Recovery
2.Data Recovery
3.13 Examples of Biometrics with Pros and Cons

Backups and Data recovery intro

Backups are a very important process regarding data security. In the event we get breached or a disk gets corrupted, having a backup can considerably ease our lives.

Companies follow strategic rules to regularly backup their data, using or combining the three main types of backing up the information at scheduled times:

  • Full backup: complete backup of all the data. This yields a thorough protection since all the files in the disk will be saved but also demands - depending on the size of the backup - a considerable amount of time and data storage capacity.

  • Incremental backup: it consists in only backing up the data that has changed in the period of time comprised since the previous backup. Only new contents will be saved and takes much less time and storage space to perform compared to the full backup.

  • Differential backup: it is a combination of the two above. It consists in performing an initial full backup and then performing incremental backups during a period of time, i.e. taking a full backup on Monday at 2:00am and performing planned incremental backups during the week, once or twice a day until next Monday morning arrives.

There are also 3 main different options we have to store our backups:

  • On-site backup: it’s stored in the same building as the original data. It may be quicker to find and recover the data from it but risks being damaged if the whole area of the building is damaged.

  • Off-site backup: stored in a different place than the building the original data is located in, this is generally a much more secure way of storing backups since they will be safe from the harm that may affect the original data, i.e. fire or another natural disaster, despite the loss in speed of accessing them.

  • Cloud backup: similar to off-site backup but you can sync in real time your original data with the backup in the cloud. The con of having a cloud backup is a potential cyber attack, increasing the need for the choice of the platform to be assessed around security itself.

Data recovery (and DiskDigger features)

Say you didn’t have a backup of your data or you lost both the original data and the backup in an accident: you’d want to use a tool to recover your data.

There is a myriad of tools out there to help you perform this task, both paid and free. If you are in Windows 10, chances are you can use Windows File Recovery.

However, if this doesn’t suit you, you can always use alternatives like DiskDigger.

You should have a recovery tool prior to a data loss event, since by downloading it and installing it you could be overwriting the very information you want to access. The way data is recovered off the disks is by looking in the place it originally was, as it really didn’t go anywhere. When you delete something it’s just the entry saying to the computer where the data you are looking for is located in your hard drive, so after deleting it, it’s just overwritten by new data. This doesn’t happen the same way in SSDs since the cells that aren’t being used get systematically deleted to free up space.

DiskDigger has two modes of operation: “Dig Deep” and “Dig Deeper”. The former one recovers any type of files from a SD memory card or a hard drive with Windows and Linux partition formats. The latter one does what the former does but scans the whole disk looking for traces of specific file types, including images, documents, audio and video, compressed archives and miscellaneous like ISOs, AutoCad drawings or TrueType fonts. For a comprehensive list of all the files supported by this method you can click here.

Biometrics, advantages and disadvantages

What is Biometrics?

We are human and by our own amazing nature, there are no 2 equal individuals. Since we are all different to each others, we can use our own bodies to identify ourselves. For example, Police Agencies around the world have been using fingerprint identification to identify suspects since the 19th century. So Biometrics is the art of of analysing the unique physical or behavioural characteristics to differentiate from one another. We do this digitally by first reading the biometrics of our subject and then encoding them and storing them in a database which we will use afterward to cross reference in the future. In the present 2 different techniques exist: contact (fingerprints) and contactless (iris scan, retinal scan, facial recognition).

Biometrics are used in facilities to ensure certain areas of interest are only accessed by authorised personnel. A bad actor could spoof the identity of a worker of the facility and gain access to restricted data and backups of the original data by fooling the biometrics systems, so we need to understand the concept of biometrics.

Examples of Biometrics and their pros and cons

  • Fingerprints:

    • Type:
      • Contact
    • Pros:
      • Speed of recognition
      • Not expensive
      • Widely used
    • Cons:
      • Not very useful if the fingers are dirty or damaged
      • The reader must be always clean
      • Can be spoofed
  • Retinal scan:

    • Type:
      • Contactless
    • Pros:
      • Can’t be spoofed
      • Highly efficient
      • Low computing memory required
    • Cons:
      • “Failure to Enroll” parameter ratio high
      • Light exposure concern due to the mentioned point above
      • User must look straight into the scanner
  • Facial recognition:

    • Type:
      • Contactless
    • Pros:
      • Used by Law Enforcement Agencies
      • Non-intrusive
      • Can be taken from a long distance
    • Cons:
      • Can be spoofed
      • False acceptance and false reject rates fluctuate
      • Privacy concerns


Mike Bedford, 15 Jun 2020. Tech Advisor - “How to Recover Deleted Files” [Online]
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Chris Hoffman, 3 Jul 2020. How-To Geek - “How to Use Microsoft’s “Windows File Recovery” on Windows 10” [Online]
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Anon., 2020. DiskDigger - “Features” [Online]
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Anon., 2020. Medical Discoveries - “Retinography” [Online]
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Last visited on 07 Dec 2020.

Anon., 2020. Tech Business Guide - “6 Disadvantages Of Facial Recognition You Need To Be Aware Of” [Online]
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Last visited on 07 Dec 2020.

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