Results 1 to 10 of 10

Thread: Trivia: recursive zip files

  1. #1
    Member
    Join Date
    Feb 2010
    Location
    Nordic
    Posts
    200
    Thanks
    41
    Thanked 36 Times in 12 Posts

    Trivia: recursive zip files


  2. #2
    Member m^2's Avatar
    Join Date
    Sep 2008
    Location
    Ślůnsk, PL
    Posts
    1,612
    Thanks
    30
    Thanked 65 Times in 47 Posts
    Cool
    I can totally see this being used to make some apps (antiviruses?) hang.
    Wow, Total Commander's search with unlimited recursion depth didn't hang. Looks cool, but I think in this case it's a sign of a bug.
    Last edited by m^2; 10th April 2012 at 19:55.

  3. #3
    Member
    Join Date
    Jun 2009
    Location
    Kraków, Poland
    Posts
    1,471
    Thanks
    26
    Thanked 120 Times in 94 Posts
    Such recursion is rather easy to detect IMO. AFAIR there were attempts to destabilize AVs by creating very reduntant ZIP files with a deep recursion (but finite) and different filenames in archives. I think AVs today are smart enough to just give up on such archives.

  4. #4
    Member
    Join Date
    Feb 2010
    Location
    Nordic
    Posts
    200
    Thanks
    41
    Thanked 36 Times in 12 Posts

    Arrow Triva: Ukkonen's suffix tree

    More trivia links:

    Ukkonen's suffix tree explained nicely:

    http://stackoverflow.com/questions/9...nglish#9513423

  5. #5
    Member
    Join Date
    Jun 2009
    Location
    Kraków, Poland
    Posts
    1,471
    Thanks
    26
    Thanked 120 Times in 94 Posts
    Too bad I already understand Ukkonen's on-line suffix tree construction

    When learning I've started from Mark Nelson's article (as it's on the first results page in Google), but probably the most helpful things was the article http://www.allisons.org/ll/AlgDS/Tree/Suffix/ as it introduced a concept called "Bottom node" which makes algorithm more straightforward and reduces the coupling between functions. Also suffix tree applet from: http://illya-keeplearning.blogspot.c...va-applet.html was very helpful for me.

    Such bottom node IMO shares a lot of similarities with order -1 coding and, indeed, the only place where I do order -1 coding in my to-be-released on-line suffix tree based compressor is when descending from bottom node to root node.
    Last edited by Piotr Tarsa; 12th April 2012 at 11:17.

  6. #6
    Member Karhunen's Avatar
    Join Date
    Dec 2011
    Location
    USA
    Posts
    91
    Thanks
    2
    Thanked 1 Time in 1 Post
    Hmm I mentioned this to Matt a month ago.. or did I ? Time only goes in one direction, doesn't it? Anyway, good luck to the 1st person who does this in ZPAQ.
    I imagine it should be easier if it were a .lzma file, as I believe there is no CRC

  7. #7
    Expert
    Matt Mahoney's Avatar
    Join Date
    May 2008
    Location
    Melbourne, Florida, USA
    Posts
    3,255
    Thanks
    306
    Thanked 778 Times in 485 Posts
    I tried a brute force search for files that compress to themselves. Didn't work.

  8. #8
    Member m^2's Avatar
    Join Date
    Sep 2008
    Location
    Ślůnsk, PL
    Posts
    1,612
    Thanks
    30
    Thanked 65 Times in 47 Posts
    Quote Originally Posted by Matt Mahoney View Post
    I tried a brute force search for files that compress to themselves. Didn't work.
    Did you try all of them?


  9. #9
    Member
    Join Date
    Feb 2010
    Location
    Nordic
    Posts
    200
    Thanks
    41
    Thanked 36 Times in 12 Posts
    Trivia: http://www.ludumdare.com/compo/ is this weekend

  10. #10
    Member
    Join Date
    Feb 2010
    Location
    Nordic
    Posts
    200
    Thanks
    41
    Thanked 36 Times in 12 Posts
    Trivia: using BWT for search of gene sequences: http://blog.avadis-ngs.com/2012/04/e...h-using-bwt-2/

Similar Threads

  1. Recursive LZ
    By chornobyl in forum Data Compression
    Replies: 1
    Last Post: 29th September 2018, 12:28
  2. Recursive data compression patent for sale
    By Matt Mahoney in forum Data Compression
    Replies: 52
    Last Post: 10th January 2012, 01:18
  3. Researchers warn of malware hidden in .zip files
    By Surfer in forum The Off-Topic Lounge
    Replies: 4
    Last Post: 20th April 2010, 09:19
  4. QuickLZ ZIP - new zip/deflate library
    By Lasse Reinhold in forum Forum Archive
    Replies: 23
    Last Post: 1st October 2007, 22:08
  5. Replies: 12
    Last Post: 30th June 2007, 16:49

Posting Permissions

  • You may not post new threads
  • You may not post replies
  • You may not post attachments
  • You may not edit your posts
  •