How signature-based search algorithms work in data recovery applications

Rate this item
(0 votes)

b2ap3_thumbnail_iStock_000025193225XSmall.jpgSignature-based search is the most essential algorithm used in data recovery applications. This algorithm facilitates data recovery from formatted, damaged or failed disks.

Signature-based search

Signature-based search allows applications to recover data from damaged, formatted or partitioned disks. Among tools employing this algorithm are Power Search, Content-Aware Analysis, Smart Scan, etc.

File identification

Signature-based search algorithm works similarly to antivirus software. Virus removal tool scans a file for fragments containing virus codes while signature-based search algorithm, employed by the data recovery application, scans the disk platter for sectors containing “deleted” data. File headers (signatures) contain symbols typical of only certain files. For example, JPEG files are identified by “JFIF” sequence, ZIP archives are indicated with “PK” at the beginning of the file header. PDF documents are marked with “%PDF” in the beginning of the file header.

Such files as HTML have no characteristic signatures but may be identified by indirect indicators since they contain ASCII symbols.

File size determination

To recover a file it is not enough to find where it begins. To complete data recovery OS must “know” where this file ends. File’s end may be found only if its size is known. File size is determined by analysis of the file header (ZIP, JPEG, AVI, etc.) or by analysis of sectors of the disk platter which immediately follow the file beginning. For example, the signature-based search algorithm will identify the sector as the HTML or TXT file’s end if this sector doesn’t contain symbols from ASCII table.


Signature-based search is not cure-all solution. Re-recorded and fragmented files (especially large files) are probably one of the biggest headaches in data recovery.

Hybrid algorithms

Modern data recovery tools employ hybrid approach to the analysis of the disk sectors. The main idea of which is to retrieve as much information from the file system as possible and to use signature-based search as little as possible – only by damaged or failed file system or by search of data deleted long time ago.

Last modified on Tuesday, 19 May 2015 17:28
Data Recovery Expert

Viktor S., Ph.D. (Electrical/Computer Engineering), was hired by DataRecoup, the international data recovery corporation, in 2012. Promoted to Engineering Senior Manager in 2010 and then to his current position, as C.I.O. of DataRecoup, in 2014. Responsible for the management of critical, high-priority RAID data recovery cases and the application of his expert, comprehensive knowledge in database data retrieval. He is also responsible for planning and implementing SEO/SEM and other internet-based marketing strategies. Currently, Viktor S., Ph.D., is focusing on the further development and expansion of DataRecoup’s major internet marketing campaign for their already successful proprietary software application “Data Recovery for Windows” (an application which he developed).


  • Comment Link Wilford Tuesday, 27 February 2018 13:42 posted by Wilford

    Asphalt driveway value are simple to estimate.

  • Comment Link Charity Monday, 26 February 2018 20:32 posted by Charity

    Both House Depot and Lowes promote high quality
    garage doors.

  • Comment Link Lee Tuesday, 28 November 2017 18:12 posted by Lee

    Superb post but I was wanting to know if you could write a litte more on this subject?
    I'd be very grateful if you could elaborate a little bit further.

  • Comment Link Isabelle Wednesday, 22 November 2017 05:13 posted by Isabelle

    hey there and thank you for your information –
    I have certainly picked up anything new from right here.
    I did however expertise a few technical points using this
    site, as I experienced to reload the site lots of
    times previous to I could get it to load properly. I had been wondering if your
    web host is OK? Not that I'm complaining, but sluggish loading instances times will often affect
    your placement in google and can damage your high quality score if advertising and marketing with Adwords.

    Anyway I am adding this RSS to my e-mail and can look out for
    a lot more of your respective intriguing content. Ensure that you update
    this again very soon.

  • Comment Link Melanie Saturday, 18 November 2017 18:06 posted by Melanie

    Wonderful beat ! I wish to apprentice at the same time as you amend your site, how can i subscribe for a blog web site?
    The account helped me a acceptable deal. I were tiny
    bit acquainted of this your broadcast offered brilliant transparent idea

  • Comment Link Shona Monday, 13 November 2017 10:13 posted by Shona

    This web site really has all of the info I wanted about this subject and
    didn't know who to ask.

  • Comment Link Milagros Sunday, 12 November 2017 11:12 posted by Milagros

    For newest news you have to go to see world-wide-web and on the web I found this web site as a finest site for hottest updates.

  • Comment Link Bart Friday, 10 November 2017 08:47 posted by Bart

    Hello to all, how is all, I think every one is getting more from this
    site, and your views are nice in favor of new people.

  • Comment Link Richelle Wednesday, 08 November 2017 13:53 posted by Richelle

    If you wish for to obtain much from this paragraph then you have
    to apply such techniques to your won website.

  • Comment Link Alma Sunday, 05 November 2017 03:21 posted by Alma

    Link exchange is nothing else except it is only placing the other
    person's web site link on your page at appropriate place and other person will
    also do similar in favor of you.

Leave a comment

Make sure you enter the (*) required information where indicated. HTML code is not allowed.