Unable to unpack pkAES256-Deflate


  • Anonymous

    Hi all,
    i have a zip file here, packed with pkAES-256 Deflate algorithm and /zip is unable to unpack it. "Method not supported" is the error message.
    stable version 4.65 brings the error and the newest beta 9 brings the error and hangs up so i have to quit it via task manager.

    So my question: Is it planned to integrate the pkzip algorithm so 7-Zip can unpack such kind of files?

    Thanks in advance

  • Igor Pavlov
    Igor Pavlov

    7-Zip 9 must unpack such archives. Send me some example of "bad" archive to email. I'll check it.


  • Anonymous

    Hi, Igor and community.
    I've got similar problem with pkAES-256 Deflate and latest 7-Zip 9.15 beta.
    I can tell you that I have generated this archive by PKWARE SecureZIP.
    Passphrase for the following testing file is 123123Qaz
    Direct link to file: 123123.zip
    Thank you for digging in this problem beforehand.

  • Igor Pavlov
    Igor Pavlov

    The encryption method of that archive is too complex for 7-Zip. It uses 3DES.
    Did you use default options to create that archive?
    Maybe it's old version of SecureZIP?


  • Anonymous

    I'm sorry for slow reaction.
    I can't tell about default options, but at least I didn't change them.
    Our version of SecureZip is 12.30.0016

  • Igor Pavlov
    Igor Pavlov

    Try to encrypt another files with SecureZip.  And look what options do you have.

  • Andreas Hoppe
    Andreas Hoppe

    Hello Igor,
    I had the same problem with a ZIP-archive produced by SecureZIP, which I could't open with 7-zip. So I used the 30-day trial of SecureZIP (12.4.016) for some own tests:

    My results:
    Only the lowest encrpytion methode called "Traditional: passphrase" in SecureZIP produces an archive with ZIPCrypto-compression, which can be opened in 7-zip.
    All other encryption methodes like "strong: passphrase" results in pkAES-256 compressed archives.

    I guess the pkAES-methode is owned by pkware,inc and could never be supported by 7-zip, right?

  • Igor Pavlov
    Igor Pavlov

    What version of 7-Zip do you use?
    There is BUG in 7-Zip 9.24 alpha - 9.30 alpha versions.
    These alpha versions could not extract ZIP archives encrypted with PKWARE-AES method.
    Try 7-Zip 9.20 instead.

    Also there are still unsupported method.
    And 7-Zip doesn't support encrypted headers (encrypted filenames) in ZIP archives.

  • Andreas Hoppe
    Andreas Hoppe

    I used the 64-bit-versions of 9.25 and 9.30 of 7-zip on WIN7-64.
    confirmed...with 9.20 I can open my self produced SecureZIP-archives.


  • Andreas Hoppe
    Andreas Hoppe

    Hello Igor,

    I got now a pkAES-256 zip-file, that is now shown in 7fm to be produced with "version 61", perhaps from new pkWare SecureZIP 14. It was for me unable to open this new file - I tried the stable 7-zip versions 9.20 and the alpha 9.25.
    The older zip files with "version 51" I was able to open them.

    Therefor it would be more than nice to have a solution for with 7z. Temporarily I have to use also the ZIPReader by PKWARE to go further.


  • Hello,

    Happy and healthy new year.

    Same problem still happens using latest alpha version 7-Zip 9.32 alpha.

    > 7z l -slt archive.zip
    7-Zip 9.32 alpha  Copyright (c) 1999-2013 Igor Pavlov  2013-12-01
    Listing archive: archive.zip
    Path = archive.zip
    Type = zip
    Physical Size = 5576
    Path = filename.xls
    Folder = -
    Size = 28160
    Packed Size = 5332
    Modified = 2014-01-02 11:55:37
    Created = 2014-01-02 11:55:17
    Accessed = 2014-01-02 11:55:37
    Attributes = ....A
    Encrypted = +
    Comment =
    CRC = 34D83C98
    Method = pkAES-256 Deflate
    Host OS = FAT
    Version = 61


    Above archive unzip's just fine with latest WinZip.


    Last edit: Athanasios Oikonomou 2014-01-02