<!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="Documentation.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="Encryption%20Algorithms.html">Encryption Algorithms</a>
<img src="arrow_right.gif" alt=">>" style="margin-top: 5px">
<a href="Serpent.html">Serpent</a>
</p></div>
<div class="wikidoc">
<h1>Serpent</h1>
<div style="text-align:left; margin-top:19px; margin-bottom:19px; padding-top:0px; padding-bottom:0px">
<p>Designed by Ross Anderson, Eli Biham, and Lars Knudsen; published in 1998. It uses a 256-bit key, 128-bit block, and operates in XTS mode (see the section
<a href="Modes%20of%20Operation.html"><em>Modes of Operation</em></a>). Serpent was one of the AES finalists. It was not selected as the proposed AES algorithm even though it appeared to have a higher security margin
than the winning Rijndael [4]. More concretely, Serpent appeared to have a <em>high</em> security margin, while Rijndael appeared to have only an
<em>adequate</em> security margin [4]. Rijndael has also received some criticism suggesting that its mathematical structure might lead to attacks in the future [4].<br>
<br>
In [5], the Twofish team presents a table of safety factors for the AES finalists. Safety factor is defined as: number of rounds of the full cipher divided by the largest number of rounds that has been broken. Hence, a broken cipher has the lowest safety factor
1. Serpent had the highest safety factor of the AES finalists: 3.56 (for all supported key sizes). Rijndael-256 had a safety factor of 1.56.<br>
<br>
In spite of these facts, Rijndael was considered an appropriate selection for the AES for its combination of security, performance, efficiency, implementability, and flexibility [4]. At the last AES Candidate Conference, Rijndael got 86 votes, Serpent got 59
votes, Twofish got 31 votes, RC6 got 23 votes, and MARS got 13 votes [18, 19].*</p>
<p>* These are positive votes. If negative votes are subtracted from the positive votes, the following results are obtained: Rijndael: 76 votes, Serpent: 52 votes, Twofish: 10 votes, RC6: -14 votes, MARS: -70 votes [19].</p>
<p> </p>
<p><a href="Twofish.html" style="text-align:left; color:#0080c0; text-decoration:none; font-weight:bold.html">Next Section >></a></p>
</div>
</div><div class="ClearBoth"></div></body></html>
