<!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="Technical%20Details.html">Technical Details</a> <img src="arrow_right.gif" alt=">>" style="margin-top: 5px"> <a href="Notation.html">Notation</a> </p></div> <div class="wikidoc"> <h1>Notation</h1> <p> </p> <table cellspacing="0"> <tbody> <tr> <td><em>C</em></td> <td>Ciphertext block</td> </tr> <tr> <td><em>DK()</em></td> <td>Decryption algorithm using encryption/decryption key <em>K</em></td> </tr> <tr> <td><em>EK()</em></td> <td>Encryption algorithm using encryption/decryption key <em>K</em></td> </tr> <tr> <td><em>H()</em></td> <td>Hash function</td> </tr> <tr> <td><em>i</em></td> <td>Block index for n-bit blocks; n is context-dependent</td> </tr> <tr> <td><em>K</em></td> <td>Cryptographic key</td> </tr> <tr> <td><em>^</em></td> <td>Bitwise exclusive-OR operation (XOR)</td> </tr> <tr> <td><em>⊕</em></td> <td>Modulo 2n addition, where n is the bit size of the left-most operand and of the resultant value (e.g., if the left operand is a 1-bit value, and the right operand is a 2-bit value, then: 1 ⊕ 0 = 1; 1 ⊕ 1 = 0; 1 ⊕ 2 = 1; 1 ⊕ 3 = 0; 0 ⊕ 0 = 0; 0 ⊕ 1 = 1; 0 ⊕ 2 = 0; 0 ⊕ 3 = 1)</td> </tr> <tr> <td><em>⊗</em></td> <td>Modular multiplication of two polynomials over the binary field GF(2) modulo x128+x7+x2+x+1 (GF stands for Galois Field)</td> </tr> <tr> <td><em>||</em></td> <td>Concatenation</td> </tr> </tbody> </table> <p> </p> <p><a href="Encryption%20Scheme.html" style="text-align:left; color:#0080c0; text-decoration:none; font-weight:bold.html">Next Section >></a></p> </div> </body></html>