www.7-zip.org/7z.html

   1 <!DOCTYPE HTML PUBLIC "-//W3C//DTD HTML 4.0 Transitional//EN">\r
   2 <HTML><HEAD>\r
   3 <META http-equiv="CONTENT-TYPE" content="TEXT/HTML; CHARSET=UTF-8">\r
   4 <LINK href="/style.css" rel="stylesheet" type="text/css">\r
   5 <TITLE>7z Format</TITLE>\r
   6 <META name="keywords" content="7z, lzma, 7-zip, archiver, free, compression, zip, \r
   7 best, compress, solid, high, ratio, unzip, far, win32, 7zip, long, file, names">\r
   8 </HEAD>\r
   9 <BODY>\r
  10 <TABLE cellspacing=10 cellpadding=10 border=0 width="100%"><TR>\r
  11 <TD class="MenuColumn" valign="top">\r
  12 <TABLE cellpadding=2 cellspacing=0 border=0 width="100%">\r
  13 <TR><TD><IMG width=110 height=63 src="/7ziplogo.png" alt="7-Zip" border=0></TD></TR>\r
  14 <TR><TD><HR></TD></TR></TABLE>\r
  15 <TABLE cellpadding="2" cellspacing="0" border="0">\r
  16 <TR><TD><A href="./" class="MenuLink">Home</A></TD></TR>\r
  17 <TR><TD><SPAN class="MenuCurrent">7z Format</SPAN></TD></TR>\r
  18 <TR><TD><A href="sdk.html" class="MenuLink">LZMA SDK</A></TD></TR>\r
  19 <TR><TD><A href="download.html" class="MenuLink">Download</A></TD></TR>\r
  20 <TR><TD><A href="faq.html" class="MenuLink">FAQ</A></TD></TR>\r
  21 <TR><TD><A href="support.html" class="MenuLink">Support</A></TD></TR>\r
  22 <TR><TD><A href="links.html" class="MenuLink">Links</A></TD></TR>\r
  23 </TABLE>\r
  24 <TABLE cellpadding=2 cellspacing=0 border=0 width="100%">\r
  25 \r
  26 <TR><TD><HR></TD></TR>\r
  27 <TR><TD>\r
  28 <form action="https://www.paypal.com/cgi-bin/webscr" method="post">\r
  29 <input type="hidden" name="cmd" value="_s-xclick">\r
  30 <input type="hidden" name="encrypted" value="-----BEGIN PKCS7-----MIIHLwYJKoZIhvcNAQcEoIIHIDCCBxwCAQExggEwMIIBLAIBADCBlDCBjjELMAkGA1UEBhMCVVMxCzAJBgNVBAgTAkNBMRYwFAYDVQQHEw1Nb3VudGFpbiBWaWV3MRQwEgYDVQQKEwtQYXlQYWwgSW5jLjETMBEGA1UECxQKbGl2ZV9jZXJ0czERMA8GA1UEAxQIbGl2ZV9hcGkxHDAaBgkqhkiG9w0BCQEWDXJlQHBheXBhbC5jb20CAQAwDQYJKoZIhvcNAQEBBQAEgYC8G9F1Yqp7tUuQLpoqj7aQ1qV5AK1qWr62jkzi0sRyb3x07bvROBYeSztJ+OdTrAwESAx+DJIg4rqvS9gbOdbe9u/e7S09gMwKtFl1PPxSGGUXa9DX6BI3Q/K/PC8xUPA7o3W6dS2EKJEcb/V5drYs4K7OJAMky8mQJmL3Ch1zgzELMAkGBSsOAwIaBQAwgawGCSqGSIb3DQEHATAUBggqhkiG9w0DBwQIzBfTq++MFVSAgYiT/QnYYN0ybsRs+cna6SEtOma4ojTEAuO0mEZe2VCY9T+8OpoYv0c0dN0QgrMqWHzigGeSIxmRpzsBq5xmPzXFSRAPklaPH6v6zuqD/pzYiCqrtTmhvU8WZj8VyQDM3fmyNN7Ad6h3qpqMaB1fABEEJW01yQARYokUueuUawxkaE1YUqz6w7wtoIIDhzCCA4MwggLsoAMCAQICAQAwDQYJKoZIhvcNAQEFBQAwgY4xCzAJBgNVBAYTAlVTMQswCQYDVQQIEwJDQTEWMBQGA1UEBxMNTW91bnRhaW4gVmlldzEUMBIGA1UEChMLUGF5UGFsIEluYy4xEzARBgNVBAsUCmxpdmVfY2VydHMxETAPBgNVBAMUCGxpdmVfYXBpMRwwGgYJKoZIhvcNAQkBFg1yZUBwYXlwYWwuY29tMB4XDTA0MDIxMzEwMTMxNVoXDTM1MDIxMzEwMTMxNVowgY4xCzAJBgNVBAYTAlVTMQswCQYDVQQIEwJDQTEWMBQGA1UEBxMNTW91bnRhaW4gVmlldzEUMBIGA1UEChMLUGF5UGFsIEluYy4xEzARBgNVBAsUCmxpdmVfY2VydHMxETAPBgNVBAMUCGxpdmVfYXBpMRwwGgYJKoZIhvcNAQkBFg1yZUBwYXlwYWwuY29tMIGfMA0GCSqGSIb3DQEBAQUAA4GNADCBiQKBgQDBR07d/ETMS1ycjtkpkvjXZe9k+6CieLuLsPumsJ7QC1odNz3sJiCbs2wC0nLE0uLGaEtXynIgRqIddYCHx88pb5HTXv4SZeuv0Rqq4+axW9PLAAATU8w04qqjaSXgbGLP3NmohqM6bV9kZZwZLR/klDaQGo1u9uDb9lr4Yn+rBQIDAQABo4HuMIHrMB0GA1UdDgQWBBSWn3y7xm8XvVk/UtcKG+wQ1mSUazCBuwYDVR0jBIGzMIGwgBSWn3y7xm8XvVk/UtcKG+wQ1mSUa6GBlKSBkTCBjjELMAkGA1UEBhMCVVMxCzAJBgNVBAgTAkNBMRYwFAYDVQQHEw1Nb3VudGFpbiBWaWV3MRQwEgYDVQQKEwtQYXlQYWwgSW5jLjETMBEGA1UECxQKbGl2ZV9jZXJ0czERMA8GA1UEAxQIbGl2ZV9hcGkxHDAaBgkqhkiG9w0BCQEWDXJlQHBheXBhbC5jb22CAQAwDAYDVR0TBAUwAwEB/zANBgkqhkiG9w0BAQUFAAOBgQCBXzpWmoBa5e9fo6ujionW1hUhPkOBakTr3YCDjbYfvJEiv/2P+IobhOGJr85+XHhN0v4gUkEDI8r2/rNk1m0GA8HKddvTjyGw/XqXa+LSTlDYkqI8OwR8GEYj4efEtcRpRYBxV8KxAW93YDWzFGvruKnnLbDAF6VR5w/cCMn5hzGCAZowggGWAgEBMIGUMIGOMQswCQYDVQQGEwJVUzELMAkGA1UECBMCQ0ExFjAUBgNVBAcTDU1vdW50YWluIFZpZXcxFDASBgNVBAoTC1BheVBhbCBJbmMuMRMwEQYDVQQLFApsaXZlX2NlcnRzMREwDwYDVQQDFAhsaXZlX2FwaTEcMBoGCSqGSIb3DQEJARYNcmVAcGF5cGFsLmNvbQIBADAJBgUrDgMCGgUAoF0wGAYJKoZIhvcNAQkDMQsGCSqGSIb3DQEHATAcBgkqhkiG9w0BCQUxDxcNMTIwMjIxMTkwNjIzWjAjBgkqhkiG9w0BCQQxFgQUL3zwPrNya0k6JChZKiBVElErxCUwDQYJKoZIhvcNAQEBBQAEgYA6iMCFHWYSQv+itFi1icdosBuz59TAUb1KFzI5j+xr2qxmGP1Z1j3ttSZtf8hSAmSJX/vk2J+1i4rUMf809L82wAb3G4HhpfpkHwMiTSntO4D1mXhpiWJ4o+Hy5aabPRWHN7uM4idaXKvvRhTPJmn/3v1e3iM9XoqVam0P3HYRbQ==-----END PKCS7-----\r
  31 ">\r
  32 <input type="image" src="https://www.paypalobjects.com/en_US/i/btn/btn_donate_LG.gif" border="0" name="submit" alt="PayPal - The safer, easier way to pay online!">\r
  33 <img alt="" border="0" src="https://www.paypalobjects.com/en_US/i/scr/pixel.gif" width="1" height="1">\r
  34 </form>\r
  35 </TD></TR>\r
  36 <TR><TD><A href="http://sourceforge.net/projects/sevenzip/"><IMG src="http://sourceforge.net/sflogo.php?group_id=14481&type=11" width=120 height=30 border=0 alt="7-Zip at SourceForge.net"></A></TD></TR>\r
  37 <TR><TD><HR></TD></TR>\r
  38 \r
  39 </TABLE>\r
  40 \r
  41 <P>\r
  42 <B>English</B><BR>\r
  43 <A href="http://7zip.usb-drivers.org/">Afrikaans</A><BR>\r
  44 <A href="http://7zip-ar.com/">Arabic</A><BR>\r
  45 <A href="http://7-zip.hit.bg/">Bulgarian</A><BR>\r
  46 <A href="http://sparanoid.com/lab/7z/">Chinese Simpl.</A><BR>\r
  47 <A href="http://www.developershome.com/7-zip/">Chinese Trad.</A><BR>\r
  48 <A href="http://7zip-eo.rnbastos.com/">Esperanto</A><BR>\r
  49 <A href="http://www.spiroo.be/7zip/">French</A><BR>\r
  50 <A href="http://www.7-zip.de/">German</A><BR>\r
  51 <A href="http://7-zip.hu/">Hungarian</A><BR>\r
  52 <A href="http://sevenzip.sourceforge.jp/">Japanese</A><BR>\r
  53 <A href="http://7-zip.ir/">Persian</A><BR>\r
  54 <A href="http://7-zip.org.pl/">Polish</A><BR>\r
  55 <A href="http://7zip.rnbastos.com/">Portuguese Brazil</A><BR>\r
  56 <A href="http://7-zip.org.ua/ru/">Russian</A><BR>\r
  57 <A href="http://7-zip.com.mx">Spanish</A><BR>\r
  58 <A href="http://7zip-thai.inetbridge.net/">Thai</A><BR>\r
  59 <A href="http://7-zip.org.ua/">Ukrainian</A><BR>\r
  60 \r
  61 </P>\r
  62 \r
  63           \r
  64 </TD>\r
  65 <TD valign="top">\r
  66 \r
  67 <H1>7z Format</H1>\r
  68 \r
  69 <P><B>7z</B> is the new archive format, providing high compression ratio.</P>\r
  70 \r
  71 <P>The main features of <B>7z</B> format:</P>\r
  72 <UL>\r
  73   <LI>Open architecture\r
  74   <LI>High compression ratio\r
  75   <LI>Strong AES-256 encryption\r
  76   <LI>Ability of using any compression, conversion or encryption method\r
  77   <LI>Supporting files with sizes up to 16000000000 GB\r
  78   <LI>Unicode file names\r
  79   <LI>Solid compressing\r
  80   <LI>Archive headers compressing\r
  81 </UL>\r
  82 \r
  83 <P><B>7z</B> has open architecture, so it can support any new compression methods.\r
  84 Now the following methods are integrated to <B>7z</B>:</P>\r
  85 \r
  86 <TABLE cellspacing ="2" cellpadding ="4">\r
  87   <TR> <TH class="Title" width="60">Method</TH> <TH class="Title">Description</TH></TR>\r
  88   <TR> <TD class="Item">LZMA</TD> <TD class="Item">Improved and optimized version of LZ77 algorithm</TD></TR>\r
  89   <TR> <TD class="Item">LZMA2</TD> <TD class="Item">Improved version of LZMA</TD></TR>\r
  90   <TR> <TD class="Item">PPMD</TD> <TD class="Item">Dmitry Shkarin's PPMdH with small changes</TD></TR>\r
  91   <TR> <TD class="Item">BCJ</TD> <TD class="Item">Converter for 32-bit x86 executables</TD></TR>\r
  92   <TR> <TD class="Item">BCJ2</TD> <TD class="Item">Converter for 32-bit x86 executables</TD></TR>\r
  93   <TR> <TD class="Item">BZip2</TD> <TD class="Item">Standard BWT algorithm</TD></TR>\r
  94   <TR> <TD class="Item">Deflate</TD> <TD class="Item">Standard LZ77-based algorithm</TD></TR>\r
  95 </TABLE>\r
  96 \r
  97 <P><B>LZMA</B> is default and general compression method of <B>7z</B> format. The main features of <B>LZMA</B> method:</P>\r
  98 <UL>\r
  99   <LI>High compression ratio\r
 100   <LI>Variable dictionary size (up to 4 GB)\r
 101   <LI>Compressing speed: about 1 MB/s on 2 GHz CPU\r
 102   <LI>Decompressing speed: about 10-20 MB/s on 2 GHz CPU\r
 103   <LI>Small memory requirements for decompressing (depend from dictionary size)\r
 104   <LI>Small code size for decompressing: about 5 KB\r
 105   <LI>Supporting multi-threading and P4's hyper-threading\r
 106 </UL>\r
 107 \r
 108 <P><B>LZMA</B> compression algorithm is very suitable for embedded applications.\r
 109 <B>LZMA</B> is released under the terms of the GNU LGPL. <B>LZMA</B> is also \r
 110 available under a proprietary license for those who can not use the GNU LGPL in \r
 111 their code. If you want to use <B>LZMA</B> code, you can ask consultations, \r
 112 custom code programming and required developer licenses \r
 113 from page for support:\r
 114 <A href="support.html">Send message to LZMA developer</A>.\r
 115 Check also information about <A href ="sdk.html">LZMA SDK</A>.</P>\r
 116 \r
 117 <P>7-Zip also supports encryption with AES-256 algorithm. \r
 118 This algorithm uses cipher key with length of 256 bits. To create that key 7-Zip \r
 119 uses derivation function based on SHA-256 hash algorithm.\r
 120 A key derivation function produces a derived key from text password defined by user.\r
 121 For increasing the cost of exhaustive search for passwords 7-Zip uses big number \r
 122 of iterations to produce cipher key from text password.</P>\r
 123 \r
 124 <P><B>7z</B> is a part of <A href="./">7-Zip</A> program distributed under the GNU LGPL. \r
 125 You can download <B>7-Zip</B> sources and binaries from <A href ="download.html">Download Page</A>.</P>\r
 126 \r
 127 <p>Applications that support <B>7z</B> archives: WinRAR, PowerArchiver, TUGZip, IZArc.</p>\r
 128 \r
 129 <p>Links:</p>\r
 130 <ul>\r
 131 <li><A href="http://en.wikipedia.org/wiki/7z">7z at Wikipedia</A></li>\r
 132 </ul>\r
 133 \r
 134 \r
 135 <HR>\r
 136 <P><SMALL>Copyright (C) 2014 Igor Pavlov.</SMALL></P>\r
 137 </TD></TR></TABLE>\r
 138 \r
 139 </BODY></HTML>\r