
This document will mostly cover the method used for sai's user created. It's been found that some preliminary files such as thumbnails and the archive responsible for swatches/palettes use a different decryption key, block size, and Table-Block location. The file itself is encrypted in ECB blocks in which any randomly accessed block can be decrypted by also decrypting the appropriate Table-Block and accessing its 32-bit key found within. Each layer, mask, and related meta data is stored in an individual pseudo-file which also has a layer of block-level encryption. sai file among with other files such as thumbnails, the sai.ssd file and others is but an archive containing a file-system-like structure once decrypted. sai as its document format for storing both raster and vector layers as well as other canvas related meta-data.


PaintTool SAI is high quality and lightweight painting software, fully digitizer support, amazing anti-aliased paintings, provide easy and stable operation, this software make digital art more enjoyable and comfortable. This document assumes you have some knowledge of the C and C++ syntax as the data structures and algorithms here will be presented in the form of C and C++ structures and subroutines. Previous work includes my now-abandoned run-time exploitation framework SaiPal and the more recent Windows explorer thumbnail extension SaiThumbs. If you find anything in this document to be misleading, incomplete, or flat-out incorrect feel free to shoot me an email at Wunkolo (at).

sai files or just to get a comprehensive understanding of the decisions that SYSTEMAX has chosen to make for their file format. This document is more directed at anyone that wants to implement their own library to read or interface with. sai file format used to archive a user's artwork and the layers of abstraction implemented by SYSTEMAX for extracting this data outside of the context of the original software. This write-up in particular is focused on the technical specifications of the user-created. This document represents about a year and a half of off-and-on hobby-research on reverse engineering the digitizing raster/vector art program PaintTool Sai.
