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diff --git a/doc/html/Hardware Acceleration.html b/doc/html/Hardware Acceleration.html new file mode 100644 index 00000000..76afc60c --- /dev/null +++ b/doc/html/Hardware Acceleration.html @@ -0,0 +1,69 @@ +<!DOCTYPE html PUBLIC "-//W3C//DTD XHTML 1.0 Transitional//EN" + "http://www.w3.org/TR/xhtml1/DTD/xhtml1-transitional.dtd"> +<html xmlns="http://www.w3.org/1999/xhtml" xml:lang="en" lang="en"> +<head> +<meta http-equiv="content-type" content="text/html; charset=utf-8" /> +<title>VeraCrypt - Free Open source disk encryption with strong security for the Paranoid</title> +<meta name="description" content="VeraCrypt is free open-source disk encryption software for Windows, Mac OS X and Linux. In case an attacker forces you to reveal the password, VeraCrypt provides plausible deniability. In contrast to file encryption, data encryption performed by VeraCrypt is real-time (on-the-fly), automatic, transparent, needs very little memory, and does not involve temporary unencrypted files."/> +<meta name="keywords" content="encryption, security"/> +<link href="styles.css" rel="stylesheet" type="text/css" /> +</head> +<body> + +<div> +<a href="https://www.veracrypt.fr/en/Home.html"><img src="VeraCrypt128x128.png" alt="VeraCrypt"/></a> +</div> + +<div id="menu"> + <ul> + <li><a href="Home.html">Home</a></li> + <li><a href="/code/">Source Code</a></li> + <li><a href="Downloads.html">Downloads</a></li> + <li><a class="active" href="Documentation.html">Documentation</a></li> + <li><a href="Donation.html">Donate</a></li> + <li><a href="https://sourceforge.net/p/veracrypt/discussion/" target="_blank">Forums</a></li> + </ul> +</div> + +<div> +<p> +<a href="Documentation.html">Documentation</a> +<img src="arrow_right.gif" alt=">>" style="margin-top: 5px"> +<a href="Hardware%20Acceleration.html">Hardware Acceleration</a> +</p></div> + +<div class="wikidoc"> +<h1>Hardware Acceleration</h1> +<div style="text-align:left; margin-top:19px; margin-bottom:19px; padding-top:0px; padding-bottom:0px"> +Some processors (CPUs) support hardware-accelerated <a href="AES.html" style="text-align:left; color:#0080c0; text-decoration:none.html"> +AES</a> encryption,* which is typically 4-8 times faster than encryption performed by the purely software implementation on the same processors.</div> +<div style="text-align:left; margin-top:19px; margin-bottom:19px; padding-top:0px; padding-bottom:0px"> +By default, VeraCrypt uses hardware-accelerated AES on computers that have a processor where the Intel AES-NI instructions are available. Specifically, VeraCrypt uses the AES-NI instructions that perform so-called AES rounds (i.e. the main portions of the AES + algorithm).** VeraCrypt does not use any of the AES-NI instructions that perform key generation.</div> +<div style="text-align:left; margin-top:19px; margin-bottom:19px; padding-top:0px; padding-bottom:0px"> +Note: By default, VeraCrypt uses hardware-accelerated AES also when an encrypted Windows system is booting or resuming from hibernation (provided that the processor supports the Intel AES-NI instructions).</div> +<div style="text-align:left; margin-top:19px; margin-bottom:19px; padding-top:0px; padding-bottom:0px"> +To find out whether VeraCrypt can use hardware-accelerated AES on your computer, select +<em style="text-align:left">Settings</em> > <em style="text-align:left">Performance/</em><em>Driver Configuration</em> and check the field labeled '<em style="text-align:left">Processor (CPU) in this computer supports hardware acceleration for AES</em>'.</div> +<div style="text-align:left; margin-top:19px; margin-bottom:19px; padding-top:0px; padding-bottom:0px"> +To find out whether a processor you want to purchase supports the Intel AES-NI instructions (also called "AES New Instructions"), which VeraCrypt uses for hardware-accelerated AES, please check the documentation for the processor or contact the vendor/manufacturer. + Alternatively, click <a href="http://ark.intel.com/search/advanced/?AESTech=true" style="text-align:left; color:#0080c0; text-decoration:none"> +here</a> to view an official list of Intel processors that support the AES-NI instructions. However, note that some Intel processors, which the Intel website lists as AES-NI-supporting, actually support the AES-NI instructions only with a Processor Configuration + update (for example, i7-2630/2635QM, i7-2670/2675QM, i5-2430/2435M, i5-2410/2415M). In such cases, you should contact the manufacturer of the motherboard/computer for a BIOS update that includes the latest Processor Configuration update for the processor.</div> +<div style="text-align:left; margin-top:19px; margin-bottom:19px; padding-top:0px; padding-bottom:0px"> +If you want to disable hardware acceleration of AES (e.g. because you want VeraCrypt to use only a fully open-source implementation of AES), you can do so by selecting<em style="text-align:left"> Settings</em> > +<em style="text-align:left">Performance and Driver Options </em>and disabling the option '<em style="text-align:left">Accelerate AES encryption/decryption by using the AES instructions of the processor</em>'. Note that when this setting is changed, the operating + system needs to be restarted to ensure that all VeraCrypt components internally perform the requested change of mode. Also note that when you create a VeraCrypt Rescue Disk, the state of this option is written to the Rescue Disk and used whenever you boot + from it (affecting the pre-boot and initial boot phase). To create a new VeraCrypt Rescue Disk, select +<em style="text-align:left">System</em> > <em style="text-align:left">Create Rescue Disk</em>.</div> +<p> </p> +<hr align="left" size="1" width="189" style="text-align:left; height:0px; border-width:0px 1px 1px; border-style:solid; border-color:#000000"> +<p><span style="text-align:left; font-size:10px; line-height:12px">* In this chapter, the word 'encryption' also refers to decryption.</span><br style="text-align:left"> +<span style="text-align:left; font-size:10px; line-height:12px">** Those instructions are +<em style="text-align:left">AESENC</em>, <em style="text-align:left">AESENCLAST</em>, +<em style="text-align:left">AESDEC</em>, and <em style="text-align:left">AESDECLAST</em> and they perform the following AES transformations: +<em style="text-align:left">ShiftRows</em>, <em style="text-align:left">SubBytes</em>, +<em style="text-align:left">MixColumns</em>, <em style="text-align:left">InvShiftRows</em>, +<em style="text-align:left">InvSubBytes</em>, <em style="text-align:left">InvMixColumns</em>, and +<em style="text-align:left">AddRoundKey</em> (for more details about these transformations, see [3])</span><span style="text-align:left; font-size:10px; line-height:12px">.</span></p> +</div><div class="ClearBoth"></div></body></html>
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