QVD encryption

[Anonymous]

Hi,

I would like to know if Qlik uses any especial algorithm to encrypt the QVD data.

Thank you in advance.

Best Regards,

- Karla

[Anonymous]

I saw this a couple of weeks ago, but have not tried it.

Encrypt and Decrypt data in QVD

Most people rely on NTFS permissions to the QVD files to prevent sticky fingers getting to them.

[henrikalmen]

The short answer is: no. QVD:s are not encrypted.

[#4 · Accepted solution]

The posts included in Bill Markhams response are very useful - as you have seen, the short answer is not but here is some inforamtion regarding the layout

QVD Files

A QVD (QlikView Data) file is a file containing a table of data exported from QlikView. QVD is a native QlikView format and can only be written to and read by QlikView. The file format is optimized for speed when reading data from a QlikView script but it is still very compact. Reading data from a QVD file is typically 10-100 times faster than reading from other data sources.

QVD files can be read in two modes, standard (fast) and super-fast. The selected mode is determined automatically by the QlikView script engine. Super-fast mode can be utilized only when all fields or a subset thereof are read without any transformations (formulas acting upon the fields), though the renaming of fields is allowed.

A QVD file holds exactly one data table and consists of three parts:

1. A well formed XML header (in UTF-8 char set) describing the fields in the table, the layout of the subsequent information and some other meta-data.
2. Symbol tables in a byte stuffed format.
3. Actual table data in a bit-stuffed format.