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href="#Chosen-prefix_collision_attack"> <div class="vector-toc-text"> <span class="vector-toc-numb">2</span> <span>Chosen-prefix collision attack</span> </div> </a> <ul id="toc-Chosen-prefix_collision_attack-sublist" class="vector-toc-list"> </ul> </li> <li id="toc-Attack_scenarios" class="vector-toc-list-item vector-toc-level-1 vector-toc-list-item-expanded"> <a class="vector-toc-link" href="#Attack_scenarios"> <div class="vector-toc-text"> <span class="vector-toc-numb">3</span> <span>Attack scenarios</span> </div> </a> <button aria-controls="toc-Attack_scenarios-sublist" class="cdx-button cdx-button--weight-quiet cdx-button--icon-only vector-toc-toggle"> <span class="vector-icon mw-ui-icon-wikimedia-expand"></span> <span>Toggle Attack scenarios subsection</span> </button> <ul id="toc-Attack_scenarios-sublist" class="vector-toc-list"> <li id="toc-Digital_signatures" class="vector-toc-list-item vector-toc-level-2"> <a class="vector-toc-link" href="#Digital_signatures"> <div class="vector-toc-text"> <span class="vector-toc-numb">3.1</span> <span>Digital signatures</span> </div> </a> <ul id="toc-Digital_signatures-sublist" class="vector-toc-list"> </ul> </li> <li id="toc-Hash_flooding" class="vector-toc-list-item vector-toc-level-2"> <a class="vector-toc-link" href="#Hash_flooding"> <div class="vector-toc-text"> <span class="vector-toc-numb">3.2</span> <span>Hash flooding</span> </div> </a> <ul id="toc-Hash_flooding-sublist" class="vector-toc-list"> </ul> </li> </ul> </li> <li id="toc-See_also" class="vector-toc-list-item vector-toc-level-1 vector-toc-list-item-expanded"> <a class="vector-toc-link" href="#See_also"> <div class="vector-toc-text"> <span class="vector-toc-numb">4</span> <span>See also</span> </div> </a> <ul id="toc-See_also-sublist" class="vector-toc-list"> </ul> </li> <li id="toc-References" class="vector-toc-list-item vector-toc-level-1 vector-toc-list-item-expanded"> <a class="vector-toc-link" href="#References"> <div 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href="https://cs.wikipedia.org/wiki/%C3%9Atok_nalezen%C3%ADm_kolize" title="Útok nalezením kolize – Czech" lang="cs" hreflang="cs" data-title="Útok nalezením kolize" data-language-autonym="Čeština" data-language-local-name="Czech" class="interlanguage-link-target"><span>Čeština</span></a></li><li class="interlanguage-link interwiki-de mw-list-item"><a href="https://de.wikipedia.org/wiki/Kollisionsangriff" title="Kollisionsangriff – German" lang="de" hreflang="de" data-title="Kollisionsangriff" data-language-autonym="Deutsch" data-language-local-name="German" class="interlanguage-link-target"><span>Deutsch</span></a></li><li class="interlanguage-link interwiki-es mw-list-item"><a href="https://es.wikipedia.org/wiki/Ataque_de_colisi%C3%B3n" title="Ataque de colisión – Spanish" lang="es" hreflang="es" data-title="Ataque de colisión" data-language-autonym="Español" data-language-local-name="Spanish" class="interlanguage-link-target"><span>Español</span></a></li><li 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0.5em;text-align:center}.mw-parser-output .ambox .mbox-imageright{border:none;padding:2px 0.5em 2px 0;text-align:center}.mw-parser-output .ambox .mbox-empty-cell{border:none;padding:0;width:1px}.mw-parser-output .ambox .mbox-image-div{width:52px}@media(min-width:720px){.mw-parser-output .ambox{margin:0 10%}}@media print{body.ns-0 .mw-parser-output .ambox{display:none!important}}</style><table class="box-Context plainlinks metadata ambox ambox-style ambox-Context" role="presentation"><tbody><tr><td class="mbox-image"><div class="mbox-image-div"><span typeof="mw:File"><span><img alt="" src="//upload.wikimedia.org/wikipedia/en/thumb/f/f2/Edit-clear.svg/40px-Edit-clear.svg.png" decoding="async" width="40" height="40" class="mw-file-element" srcset="//upload.wikimedia.org/wikipedia/en/thumb/f/f2/Edit-clear.svg/60px-Edit-clear.svg.png 1.5x, //upload.wikimedia.org/wikipedia/en/thumb/f/f2/Edit-clear.svg/80px-Edit-clear.svg.png 2x" data-file-width="48" data-file-height="48" /></span></span></div></td><td class="mbox-text"><div class="mbox-text-span">This article <b>provides insufficient context for those unfamiliar with the subject</b>.<span class="hide-when-compact"> Please help <a class="external text" href="https://en.wikipedia.org/w/index.php?title=Collision_attack&action=edit">improve the article</a> by <a href="/wiki/Wikipedia:Writing_better_articles#Provide_context_for_the_reader" title="Wikipedia:Writing better articles">providing more context for the reader</a>.</span> <span class="date-container"><i>(<span class="date">February 2020</span>)</i></span><span class="hide-when-compact"><i> (<small><a href="/wiki/Help:Maintenance_template_removal" title="Help:Maintenance template removal">Learn how and when to remove this message</a></small>)</i></span></div></td></tr></tbody></table> <p>In <a href="/wiki/Cryptography" title="Cryptography">cryptography</a>, a <b>collision attack</b> on a <a href="/wiki/Cryptographic_hash" class="mw-redirect" title="Cryptographic hash">cryptographic hash</a> tries to find two inputs producing the same hash value, i.e. a <a href="/wiki/Hash_collision" title="Hash collision">hash collision</a>. This is in contrast to a <a href="/wiki/Preimage_attack" title="Preimage attack">preimage attack</a> where a specific target hash value is specified. </p><p>There are roughly two types of collision attacks: </p> <dl><dt>Classical collision attack</dt> <dd>Find two different messages <i>m</i><sub>1</sub> and <i>m</i><sub>2</sub> such that <i>hash</i>(<i>m</i><sub>1</sub>) = <i>hash</i>(<i>m</i><sub>2</sub>).</dd></dl> <p>More generally: </p> <dl><dt>Chosen-prefix collision attack</dt> <dd>Given two different prefixes <i>p</i><sub>1</sub> and <i>p</i><sub>2</sub>, find two suffixes <i>s</i><sub>1</sub> and <i>s</i><sub>2</sub> such that <i>hash</i>(<i>p</i><sub>1</sub> ∥ <i>s</i><sub>1</sub>) = <i>hash</i>(<i>p</i><sub>2</sub> ∥ <i>s</i><sub>2</sub>), where ∥ denotes the <a href="/wiki/Concatenation" title="Concatenation">concatenation</a> operation.</dd></dl> <meta property="mw:PageProp/toc" /> <div class="mw-heading mw-heading2"><h2 id="Classical_collision_attack">Classical collision attack</h2><span class="mw-editsection"><span class="mw-editsection-bracket">[</span><a href="/w/index.php?title=Collision_attack&action=edit&section=1" title="Edit section: Classical collision attack"><span>edit</span></a><span class="mw-editsection-bracket">]</span></span></div> <p>Much like <a href="/wiki/Symmetric-key_cipher" class="mw-redirect" title="Symmetric-key cipher">symmetric-key ciphers</a> are vulnerable to <a href="/wiki/Brute_force_attack" class="mw-redirect" title="Brute force attack">brute force attacks</a>, every <a href="/wiki/Cryptographic_hash_function" title="Cryptographic hash function">cryptographic hash function</a> is inherently vulnerable to collisions using a <a href="/wiki/Birthday_attack" title="Birthday attack">birthday attack</a>. Due to the <a href="/wiki/Birthday_problem" title="Birthday problem">birthday problem</a>, these attacks are much faster than a brute force would be. A hash of <i>n</i> bits can be broken in 2<sup><i>n</i>/2</sup> time steps (evaluations of the hash function). </p><p>Mathematically stated, a collision attack finds two different messages <i>m1</i> and <i>m2</i>, such that <i>hash(m1)</i> = <i>hash(m2)</i>. In a classical collision attack, the attacker has no control over the content of either message, but they are arbitrarily chosen by the algorithm. </p><p>More efficient attacks are possible by employing <a href="/wiki/Cryptanalysis" title="Cryptanalysis">cryptanalysis</a> to specific hash functions. When a collision attack is discovered and is found to be faster than a birthday attack, a hash function is often denounced as "broken". The <a href="/wiki/NIST_hash_function_competition" title="NIST hash function competition">NIST hash function competition</a> was largely induced by published collision attacks against two very commonly used hash functions, <a href="/wiki/MD5" title="MD5">MD5</a><sup id="cite_ref-md5-2004_1-0" class="reference"><a href="#cite_note-md5-2004-1"><span class="cite-bracket">[</span>1<span class="cite-bracket">]</span></a></sup> and <a href="/wiki/SHA-1" title="SHA-1">SHA-1</a>. The collision attacks against MD5 have improved so much that, as of 2007, it takes just a few seconds on a regular computer.<sup id="cite_ref-2" class="reference"><a href="#cite_note-2"><span class="cite-bracket">[</span>2<span class="cite-bracket">]</span></a></sup> Hash collisions created this way are usually constant length and largely unstructured, so cannot directly be applied to attack widespread document formats or protocols. </p><p>However, workarounds are possible by abusing dynamic constructs present in many formats. In this way, two documents would be created which are as similar as possible in order to have the same hash value. One document would be shown to an authority to be signed, and then the signature could be copied to the other file. Such a malicious document would contain two different messages in the same document, but conditionally display one or the other through subtle changes to the file: </p> <ul><li>Some document formats like <a href="/wiki/PostScript" title="PostScript">PostScript</a>, or <a href="/wiki/Macro_(computer_science)" title="Macro (computer science)">macros</a> in <a href="/wiki/Microsoft_Word" title="Microsoft Word">Microsoft Word</a>, have conditional constructs.<sup id="cite_ref-3" class="reference"><a href="#cite_note-3"><span class="cite-bracket">[</span>3<span class="cite-bracket">]</span></a></sup><sup id="cite_ref-special-file-formats_4-0" class="reference"><a href="#cite_note-special-file-formats-4"><span class="cite-bracket">[</span>4<span class="cite-bracket">]</span></a></sup> (if-then-else) that allow testing whether a location in the file has one value or another in order to control what is displayed.</li> <li><a href="/wiki/TIFF" title="TIFF">TIFF</a> files can contain cropped images, with a different part of an image being displayed without affecting the hash value.<sup id="cite_ref-special-file-formats_4-1" class="reference"><a href="#cite_note-special-file-formats-4"><span class="cite-bracket">[</span>4<span class="cite-bracket">]</span></a></sup></li> <li><a href="/wiki/PDF" title="PDF">PDF</a> files are vulnerable to collision attacks by using color value (such that text of one message is displayed with a white color that blends into the background, and text of the other message is displayed with a dark color) which can then be altered to change the signed document's content.<sup id="cite_ref-special-file-formats_4-2" class="reference"><a href="#cite_note-special-file-formats-4"><span class="cite-bracket">[</span>4<span class="cite-bracket">]</span></a></sup></li></ul> <div class="mw-heading mw-heading2"><h2 id="Chosen-prefix_collision_attack">Chosen-prefix collision attack</h2><span class="mw-editsection"><span class="mw-editsection-bracket">[</span><a href="/w/index.php?title=Collision_attack&action=edit&section=2" title="Edit section: Chosen-prefix collision attack"><span>edit</span></a><span class="mw-editsection-bracket">]</span></span></div> <p>An extension of the collision attack is the chosen-prefix collision attack, which is specific to <a href="/wiki/Merkle%E2%80%93Damg%C3%A5rd_construction" title="Merkle–Damgård construction">Merkle–Damgård hash functions</a>. In this case, the attacker can choose two arbitrarily different documents, and then append different calculated values that result in the whole documents having an equal hash value. This attack is normally harder, a hash of n bits can be broken in 2<sup>(n/2)+1</sup> time steps, but is much more powerful than a classical collision attack. </p><p>Mathematically stated, given two different prefixes <i>p</i><sub>1</sub>, <i>p</i><sub>2</sub>, the attack finds two suffixes <i>s</i><sub>1</sub> and <i>s</i><sub>2</sub> such that <i>hash</i>(<i>p</i><sub>1</sub> ∥ <i>s</i><sub>1</sub>) = <i>hash</i>(<i>p</i><sub>2</sub> ∥ <i>s</i><sub>2</sub>) (where ∥ is the <a href="/wiki/Concatenation" title="Concatenation">concatenation</a> operation). </p><p>More efficient attacks are also possible by employing <a href="/wiki/Cryptanalysis" title="Cryptanalysis">cryptanalysis</a> to specific hash functions. In 2007, a chosen-prefix collision attack was found against MD5, requiring roughly 2<sup>50</sup> evaluations of the MD5 function. The paper also demonstrates two <a href="/wiki/X.509" title="X.509">X.509</a> certificates for different domain names, with colliding hash values. This means that a <a href="/wiki/Certificate_authority" title="Certificate authority">certificate authority</a> could be asked to sign a certificate for one domain, and then that certificate (specially its signature) could be used to create a new rogue certificate to impersonate another domain.<sup id="cite_ref-md5-chosen-2007_5-0" class="reference"><a href="#cite_note-md5-chosen-2007-5"><span class="cite-bracket">[</span>5<span class="cite-bracket">]</span></a></sup> </p><p>A real-world collision attack was published in December 2008 when a group of security researchers published a forged <a href="/wiki/X.509" title="X.509">X.509</a> signing certificate that could be used to impersonate a <a href="/wiki/Certificate_authority" title="Certificate authority">certificate authority</a>, taking advantage of a prefix collision attack against the MD5 hash function. This meant that an attacker could impersonate any <a href="/wiki/Transport_Layer_Security" title="Transport Layer Security">SSL</a>-secured website as a <a href="/wiki/Man-in-the-middle" class="mw-redirect" title="Man-in-the-middle">man-in-the-middle</a>, thereby subverting the certificate validation built in every <a href="/wiki/Web_browser" title="Web browser">web browser</a> to protect <a href="/wiki/Electronic_commerce" class="mw-redirect" title="Electronic commerce">electronic commerce</a>. The rogue certificate may not be revokable by real authorities, and could also have an arbitrary forged expiry time. Even though MD5 was known to be very weak in 2004,<sup id="cite_ref-md5-2004_1-1" class="reference"><a href="#cite_note-md5-2004-1"><span class="cite-bracket">[</span>1<span class="cite-bracket">]</span></a></sup> certificate authorities were still willing to sign MD5-verified certificates in December 2008,<sup id="cite_ref-6" class="reference"><a href="#cite_note-6"><span class="cite-bracket">[</span>6<span class="cite-bracket">]</span></a></sup> and at least one Microsoft code-signing certificate was still using MD5 in May 2012. </p><p>The <a href="/wiki/Flame_(malware)" title="Flame (malware)">Flame</a> malware successfully used a new variation of a chosen-prefix collision attack to spoof <a href="/wiki/Code_signing" title="Code signing">code signing</a> of its components by a Microsoft root certificate that still used the compromised MD5 algorithm.<sup id="cite_ref-7" class="reference"><a href="#cite_note-7"><span class="cite-bracket">[</span>7<span class="cite-bracket">]</span></a></sup><sup id="cite_ref-8" class="reference"><a href="#cite_note-8"><span class="cite-bracket">[</span>8<span class="cite-bracket">]</span></a></sup> </p><p>In 2019, researchers found a chosen-prefix collision attack against <a href="/wiki/SHA-1" title="SHA-1">SHA-1</a> with computing complexity between 2<sup>66.9</sup> and 2<sup>69.4</sup> and cost less than 100,000 US dollars. <sup id="cite_ref-SHA-1_collision_attacks_are_now_actually_practical_and_a_looming_danger_2019_9-0" class="reference"><a href="#cite_note-SHA-1_collision_attacks_are_now_actually_practical_and_a_looming_danger_2019-9"><span class="cite-bracket">[</span>9<span class="cite-bracket">]</span></a></sup><sup id="cite_ref-Collisions_of_Chosen-Prefix_Collisions_SHA-1_2019_10-0" class="reference"><a href="#cite_note-Collisions_of_Chosen-Prefix_Collisions_SHA-1_2019-10"><span class="cite-bracket">[</span>10<span class="cite-bracket">]</span></a></sup> In 2020, researchers reduced the complexity of a chosen-prefix collision attack against SHA-1 to 2<sup>63.4</sup>. <sup id="cite_ref-SHA-1_is_a_Shambles_-_First_Chosen-Prefix_Collision_on_SHA-1_and_Application_to_the_PGP_Web_of_Trust_11-0" class="reference"><a href="#cite_note-SHA-1_is_a_Shambles_-_First_Chosen-Prefix_Collision_on_SHA-1_and_Application_to_the_PGP_Web_of_Trust-11"><span class="cite-bracket">[</span>11<span class="cite-bracket">]</span></a></sup> </p> <div class="mw-heading mw-heading2"><h2 id="Attack_scenarios">Attack scenarios</h2><span class="mw-editsection"><span class="mw-editsection-bracket">[</span><a href="/w/index.php?title=Collision_attack&action=edit&section=3" title="Edit section: Attack scenarios"><span>edit</span></a><span class="mw-editsection-bracket">]</span></span></div> <p>Many applications of cryptographic hash functions do not rely on <a href="/wiki/Collision_resistance" title="Collision resistance">collision resistance</a>, thus collision attacks do not affect their security. For example, <a href="/wiki/HMAC" title="HMAC">HMACs</a> are not vulnerable.<sup id="cite_ref-collision-qna_12-0" class="reference"><a href="#cite_note-collision-qna-12"><span class="cite-bracket">[</span>12<span class="cite-bracket">]</span></a></sup> For the attack to be useful, the attacker must be in control of the input to the hash function. </p> <div class="mw-heading mw-heading3"><h3 id="Digital_signatures">Digital signatures</h3><span class="mw-editsection"><span class="mw-editsection-bracket">[</span><a href="/w/index.php?title=Collision_attack&action=edit&section=4" title="Edit section: Digital signatures"><span>edit</span></a><span class="mw-editsection-bracket">]</span></span></div> <p>Because <a href="/wiki/Digital_signature" title="Digital signature">digital signature</a> algorithms cannot sign a large amount of data efficiently, most implementations use a hash function to reduce ("compress") the amount of data that needs to be signed down to a constant size. Digital signature schemes often become vulnerable to hash collisions as soon as the underlying hash function is practically broken; techniques like randomized (salted) hashing will buy extra time by requiring the harder <a href="/wiki/Preimage_attack" title="Preimage attack">preimage attack</a>.<sup id="cite_ref-13" class="reference"><a href="#cite_note-13"><span class="cite-bracket">[</span>13<span class="cite-bracket">]</span></a></sup> </p><p>The usual attack scenario goes like this: </p> <ol><li>Mallory creates two different documents A and B that have an identical hash value, i.e., a collision. Mallory seeks to deceive Bob into accepting document B, ostensibly from Alice.</li> <li>Mallory <b>sends document A to Alice</b>, who agrees to what the document says, signs its hash, and sends the signature to Mallory.</li> <li>Mallory attaches the signature from document A to document B.</li> <li>Mallory then <b>sends the signature and document B to Bob</b>, claiming that Alice signed B. Because the digital signature matches document B's hash, Bob's software is unable to detect the substitution.<sup class="noprint Inline-Template Template-Fact" style="white-space:nowrap;">[<i><a href="/wiki/Wikipedia:Citation_needed" title="Wikipedia:Citation needed"><span title="This claim needs references to reliable sources. (September 2023)">citation needed</span></a></i>]</sup></li></ol> <p>In 2008, researchers used a chosen-prefix collision attack against <a href="/wiki/MD5" title="MD5">MD5</a> using this scenario, to produce a rogue <a href="/wiki/Certificate_authority" title="Certificate authority">certificate authority</a> certificate. They created two versions of a <a href="/wiki/Transport_Layer_Security" title="Transport Layer Security">TLS</a> <a href="/wiki/Public_key_certificate" title="Public key certificate">public key certificate</a>, one of which appeared legitimate and was submitted for signing by the RapidSSL certificate authority. The second version, which had the same MD5 hash, contained flags which signal web browsers to accept it as a legitimate authority for issuing arbitrary other certificates.<sup id="cite_ref-14" class="reference"><a href="#cite_note-14"><span class="cite-bracket">[</span>14<span class="cite-bracket">]</span></a></sup> </p> <div class="mw-heading mw-heading3"><h3 id="Hash_flooding">Hash flooding</h3><span class="mw-editsection"><span class="mw-editsection-bracket">[</span><a href="/w/index.php?title=Collision_attack&action=edit&section=5" title="Edit section: Hash flooding"><span>edit</span></a><span class="mw-editsection-bracket">]</span></span></div> <p><b>Hash flooding</b> (also known as <b>HashDoS</b><sup id="cite_ref-15" class="reference"><a href="#cite_note-15"><span class="cite-bracket">[</span>15<span class="cite-bracket">]</span></a></sup>) is a <a href="/wiki/Denial_of_service" class="mw-redirect" title="Denial of service">denial of service</a> attack that uses hash collisions to exploit the worst-case (linear probe) runtime of <a href="/wiki/Hash_table" title="Hash table">hash table</a> lookups.<sup id="cite_ref-v8_16-0" class="reference"><a href="#cite_note-v8-16"><span class="cite-bracket">[</span>16<span class="cite-bracket">]</span></a></sup> It was originally described in 2003. To execute such an attack, the attacker sends the server multiple pieces of data that hash to the same value and then tries to get the server to perform slow lookups. As the main focus of hash functions used in hash tables was speed instead of security, most major programming languages were affected,<sup id="cite_ref-17" class="reference"><a href="#cite_note-17"><span class="cite-bracket">[</span>17<span class="cite-bracket">]</span></a></sup> with new vulnerabilities of this class still showing up a decade after the original presentation.<sup id="cite_ref-v8_16-1" class="reference"><a href="#cite_note-v8-16"><span class="cite-bracket">[</span>16<span class="cite-bracket">]</span></a></sup> </p><p>To prevent hash flooding without making the hash function overly complex, newer <a href="/wiki/Keyed_hash_function" class="mw-redirect" title="Keyed hash function">keyed hash functions</a> are introduced, with the security objective that collisions are hard to find as long as the key is unknown. They may be slower than previous hashes, but are still much easier to compute than cryptographic hashes. As of 2021, Jean-Philippe Aumasson and <a href="/wiki/Daniel_J._Bernstein" title="Daniel J. Bernstein">Daniel J. Bernstein</a>'s <a href="/wiki/SipHash" title="SipHash">SipHash</a> (2012) is the most widely-used hash function in this class.<sup id="cite_ref-SipHash_18-0" class="reference"><a href="#cite_note-SipHash-18"><span class="cite-bracket">[</span>18<span class="cite-bracket">]</span></a></sup> (Non-keyed "simple" hashes remain safe to use as long as the application's hash table is not controllable from the outside.) </p><p>It is possible to perform an analogous attack to fill up <a href="/wiki/Bloom_filter" title="Bloom filter">Bloom filters</a> using a (partial) preimage attack.<sup id="cite_ref-19" class="reference"><a href="#cite_note-19"><span class="cite-bracket">[</span>19<span class="cite-bracket">]</span></a></sup> </p> <div class="mw-heading mw-heading2"><h2 id="See_also">See also</h2><span class="mw-editsection"><span class="mw-editsection-bracket">[</span><a href="/w/index.php?title=Collision_attack&action=edit&section=6" title="Edit section: See also"><span>edit</span></a><span class="mw-editsection-bracket">]</span></span></div> <ul><li><a href="/wiki/Puzzle_friendliness" title="Puzzle friendliness">Puzzle friendliness</a></li></ul> <div class="mw-heading mw-heading2"><h2 id="References">References</h2><span class="mw-editsection"><span class="mw-editsection-bracket">[</span><a href="/w/index.php?title=Collision_attack&action=edit&section=7" title="Edit section: References"><span>edit</span></a><span class="mw-editsection-bracket">]</span></span></div> <style data-mw-deduplicate="TemplateStyles:r1239543626">.mw-parser-output .reflist{margin-bottom:0.5em;list-style-type:decimal}@media screen{.mw-parser-output .reflist{font-size:90%}}.mw-parser-output .reflist .references{font-size:100%;margin-bottom:0;list-style-type:inherit}.mw-parser-output .reflist-columns-2{column-width:30em}.mw-parser-output .reflist-columns-3{column-width:25em}.mw-parser-output .reflist-columns{margin-top:0.3em}.mw-parser-output .reflist-columns ol{margin-top:0}.mw-parser-output .reflist-columns li{page-break-inside:avoid;break-inside:avoid-column}.mw-parser-output .reflist-upper-alpha{list-style-type:upper-alpha}.mw-parser-output .reflist-upper-roman{list-style-type:upper-roman}.mw-parser-output .reflist-lower-alpha{list-style-type:lower-alpha}.mw-parser-output .reflist-lower-greek{list-style-type:lower-greek}.mw-parser-output .reflist-lower-roman{list-style-type:lower-roman}</style><div class="reflist"> <div class="mw-references-wrap mw-references-columns"><ol class="references"> <li id="cite_note-md5-2004-1"><span class="mw-cite-backlink">^ <a href="#cite_ref-md5-2004_1-0"><sup><i><b>a</b></i></sup></a> <a href="#cite_ref-md5-2004_1-1"><sup><i><b>b</b></i></sup></a></span> <span class="reference-text">Xiaoyun Wang, Dengguo Feng, Xuejia Lai, Hongbo Yu: <a rel="nofollow" class="external text" href="http://eprint.iacr.org/2004/199">Collisions for Hash Functions MD4, MD5, HAVAL-128 and RIPEMD</a>, Cryptology ePrint Archive Report 2004/199, 16 Aug 2004, revised 17 Aug 2004. Retrieved July 27, 2008.</span> </li> <li id="cite_note-2"><span class="mw-cite-backlink"><b><a href="#cite_ref-2">^</a></b></span> <span class="reference-text"><style data-mw-deduplicate="TemplateStyles:r1238218222">.mw-parser-output cite.citation{font-style:inherit;word-wrap:break-word}.mw-parser-output .citation q{quotes:"\"""\"""'""'"}.mw-parser-output .citation:target{background-color:rgba(0,127,255,0.133)}.mw-parser-output .id-lock-free.id-lock-free a{background:url("//upload.wikimedia.org/wikipedia/commons/6/65/Lock-green.svg")right 0.1em center/9px no-repeat}.mw-parser-output .id-lock-limited.id-lock-limited a,.mw-parser-output .id-lock-registration.id-lock-registration a{background:url("//upload.wikimedia.org/wikipedia/commons/d/d6/Lock-gray-alt-2.svg")right 0.1em center/9px no-repeat}.mw-parser-output .id-lock-subscription.id-lock-subscription a{background:url("//upload.wikimedia.org/wikipedia/commons/a/aa/Lock-red-alt-2.svg")right 0.1em center/9px no-repeat}.mw-parser-output .cs1-ws-icon a{background:url("//upload.wikimedia.org/wikipedia/commons/4/4c/Wikisource-logo.svg")right 0.1em center/12px no-repeat}body:not(.skin-timeless):not(.skin-minerva) .mw-parser-output .id-lock-free a,body:not(.skin-timeless):not(.skin-minerva) .mw-parser-output .id-lock-limited a,body:not(.skin-timeless):not(.skin-minerva) .mw-parser-output .id-lock-registration a,body:not(.skin-timeless):not(.skin-minerva) .mw-parser-output .id-lock-subscription a,body:not(.skin-timeless):not(.skin-minerva) .mw-parser-output .cs1-ws-icon a{background-size:contain;padding:0 1em 0 0}.mw-parser-output .cs1-code{color:inherit;background:inherit;border:none;padding:inherit}.mw-parser-output .cs1-hidden-error{display:none;color:var(--color-error,#d33)}.mw-parser-output .cs1-visible-error{color:var(--color-error,#d33)}.mw-parser-output .cs1-maint{display:none;color:#085;margin-left:0.3em}.mw-parser-output .cs1-kern-left{padding-left:0.2em}.mw-parser-output .cs1-kern-right{padding-right:0.2em}.mw-parser-output .citation .mw-selflink{font-weight:inherit}@media screen{.mw-parser-output .cs1-format{font-size:95%}html.skin-theme-clientpref-night .mw-parser-output .cs1-maint{color:#18911f}}@media screen and (prefers-color-scheme:dark){html.skin-theme-clientpref-os .mw-parser-output .cs1-maint{color:#18911f}}</style><cite id="CITEREFM.M.J._Stevens2007" class="citation journal cs1">M.M.J. Stevens (June 2007). <a rel="nofollow" class="external text" href="http://www.win.tue.nl/hashclash/On%20Collisions%20for%20MD5%20-%20M.M.J.%20Stevens.pdf">"On Collisions for MD5"</a> <span class="cs1-format">(PDF)</span>. <q>[...] we are able to find collisions for MD5 in about 2<sup>24.1</sup> compressions for recommended IHVs which takes approx. 6 seconds on a 2.6GHz Pentium 4.</q></cite><span title="ctx_ver=Z39.88-2004&rft_val_fmt=info%3Aofi%2Ffmt%3Akev%3Amtx%3Ajournal&rft.genre=article&rft.atitle=On+Collisions+for+MD5&rft.date=2007-06&rft.au=M.M.J.+Stevens&rft_id=http%3A%2F%2Fwww.win.tue.nl%2Fhashclash%2FOn%2520Collisions%2520for%2520MD5%2520-%2520M.M.J.%2520Stevens.pdf&rfr_id=info%3Asid%2Fen.wikipedia.org%3ACollision+attack" class="Z3988"></span> <span class="cs1-visible-error citation-comment"><code class="cs1-code">{{<a href="/wiki/Template:Cite_journal" title="Template:Cite journal">cite journal</a>}}</code>: </span><span class="cs1-visible-error citation-comment">Cite journal requires <code class="cs1-code">|journal=</code> (<a href="/wiki/Help:CS1_errors#missing_periodical" title="Help:CS1 errors">help</a>)</span></span> </li> <li id="cite_note-3"><span class="mw-cite-backlink"><b><a href="#cite_ref-3">^</a></b></span> <span class="reference-text"><link rel="mw-deduplicated-inline-style" href="mw-data:TemplateStyles:r1238218222"><cite id="CITEREFMagnus_DaumStefan_Lucks" class="citation web cs1">Magnus Daum; <a href="/wiki/Stefan_Lucks" title="Stefan Lucks">Stefan Lucks</a>. <a rel="nofollow" class="external text" href="https://web.archive.org/web/20100327141611/http://th.informatik.uni-mannheim.de/people/lucks/HashCollisions/">"Hash Collisions (The Poisoned Message Attack)"</a>. <i><a href="/wiki/Eurocrypt" class="mw-redirect" title="Eurocrypt">Eurocrypt</a> 2005 rump session</i>. Archived from <a rel="nofollow" class="external text" href="http://th.informatik.uni-mannheim.de/People/lucks/HashCollisions/">the original</a> on 2010-03-27.</cite><span title="ctx_ver=Z39.88-2004&rft_val_fmt=info%3Aofi%2Ffmt%3Akev%3Amtx%3Ajournal&rft.genre=unknown&rft.jtitle=Eurocrypt+2005+rump+session&rft.atitle=Hash+Collisions+%28The+Poisoned+Message+Attack%29&rft.au=Magnus+Daum&rft.au=Stefan+Lucks&rft_id=http%3A%2F%2Fth.informatik.uni-mannheim.de%2FPeople%2Flucks%2FHashCollisions%2F&rfr_id=info%3Asid%2Fen.wikipedia.org%3ACollision+attack" class="Z3988"></span></span> </li> <li id="cite_note-special-file-formats-4"><span class="mw-cite-backlink">^ <a href="#cite_ref-special-file-formats_4-0"><sup><i><b>a</b></i></sup></a> <a href="#cite_ref-special-file-formats_4-1"><sup><i><b>b</b></i></sup></a> <a href="#cite_ref-special-file-formats_4-2"><sup><i><b>c</b></i></sup></a></span> <span class="reference-text"><link rel="mw-deduplicated-inline-style" href="mw-data:TemplateStyles:r1238218222"><cite id="CITEREFMax_GebhardtGeorg_IlliesWerner_Schindler2017" class="citation journal cs1">Max Gebhardt; Georg Illies; Werner Schindler (4 January 2017). <a rel="nofollow" class="external text" href="http://csrc.nist.gov/groups/ST/hash/documents/Illies_NIST_05.pdf">"A Note on the Practical Value of Single Hash Collisions for Special File Formats"</a> <span class="cs1-format">(PDF)</span>.</cite><span title="ctx_ver=Z39.88-2004&rft_val_fmt=info%3Aofi%2Ffmt%3Akev%3Amtx%3Ajournal&rft.genre=article&rft.atitle=A+Note+on+the+Practical+Value+of+Single+Hash+Collisions+for+Special+File+Formats&rft.date=2017-01-04&rft.au=Max+Gebhardt&rft.au=Georg+Illies&rft.au=Werner+Schindler&rft_id=http%3A%2F%2Fcsrc.nist.gov%2Fgroups%2FST%2Fhash%2Fdocuments%2FIllies_NIST_05.pdf&rfr_id=info%3Asid%2Fen.wikipedia.org%3ACollision+attack" class="Z3988"></span> <span class="cs1-visible-error citation-comment"><code class="cs1-code">{{<a href="/wiki/Template:Cite_journal" title="Template:Cite journal">cite journal</a>}}</code>: </span><span class="cs1-visible-error citation-comment">Cite journal requires <code class="cs1-code">|journal=</code> (<a href="/wiki/Help:CS1_errors#missing_periodical" title="Help:CS1 errors">help</a>)</span></span> </li> <li id="cite_note-md5-chosen-2007-5"><span class="mw-cite-backlink"><b><a href="#cite_ref-md5-chosen-2007_5-0">^</a></b></span> <span class="reference-text"><link rel="mw-deduplicated-inline-style" href="mw-data:TemplateStyles:r1238218222"><cite id="CITEREFMarc_StevensArjen_LenstraBenne_de_Weger2007" class="citation book cs1">Marc Stevens; Arjen Lenstra; Benne de Weger (2007-11-30). <a rel="nofollow" class="external text" href="http://www.win.tue.nl/hashclash/ChosenPrefixCollisions/">"Chosen-Prefix Collisions for MD5 and Colliding X.509 Certificates for Different Identities"</a>. <i>Advances in Cryptology - EUROCRYPT 2007</i>. Lecture Notes in Computer Science. 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Retrieved <span class="nowrap">2009-10-07</span></span>.</cite><span title="ctx_ver=Z39.88-2004&rft_val_fmt=info%3Aofi%2Ffmt%3Akev%3Amtx%3Abook&rft.genre=unknown&rft.btitle=Creating+a+rogue+CA+certificate&rft.date=2008-12-30&rft.au=Alexander+Sotirov&rft_id=http%3A%2F%2Fwww.phreedom.org%2Fresearch%2Frogue-ca%2F&rfr_id=info%3Asid%2Fen.wikipedia.org%3ACollision+attack" class="Z3988"></span></span> </li> <li id="cite_note-7"><span class="mw-cite-backlink"><b><a href="#cite_ref-7">^</a></b></span> <span class="reference-text"><link rel="mw-deduplicated-inline-style" href="mw-data:TemplateStyles:r1238218222"><cite class="citation web cs1"><a rel="nofollow" class="external text" href="https://web.archive.org/web/20120607215605/http://blogs.technet.com/b/msrc/archive/2012/06/03/microsoft-releases-security-advisory-2718704.aspx?Redirected=true">"Microsoft releases Security Advisory 2718704"</a>. <a href="/wiki/Microsoft" title="Microsoft">Microsoft</a>. 3 June 2012. 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Retrieved <span class="nowrap">4 June</span> 2012</span>.</cite><span title="ctx_ver=Z39.88-2004&rft_val_fmt=info%3Aofi%2Ffmt%3Akev%3Amtx%3Abook&rft.genre=unknown&rft.btitle=Microsoft+releases+Security+Advisory+2718704&rft.pub=Microsoft&rft.date=2012-06-03&rft_id=http%3A%2F%2Fblogs.technet.com%2Fb%2Fmsrc%2Farchive%2F2012%2F06%2F03%2Fmicrosoft-releases-security-advisory-2718704.aspx%3FRedirected%3Dtrue&rfr_id=info%3Asid%2Fen.wikipedia.org%3ACollision+attack" class="Z3988"></span></span> </li> <li id="cite_note-8"><span class="mw-cite-backlink"><b><a href="#cite_ref-8">^</a></b></span> <span class="reference-text"><link rel="mw-deduplicated-inline-style" href="mw-data:TemplateStyles:r1238218222"><cite id="CITEREFMarc_Stevens2012" class="citation web cs1">Marc Stevens (7 June 2012). <a rel="nofollow" class="external text" href="http://www.cwi.nl/news/2012/cwi-cryptanalist-discovers-new-cryptographic-attack-variant-in-flame-spy-malware">"CWI Cryptanalist Discovers New Cryptographic Attack Variant in Flame Spy Malware"</a>. 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INRIA Grenoble.</cite><span title="ctx_ver=Z39.88-2004&rft_val_fmt=info%3Aofi%2Ffmt%3Akev%3Amtx%3Adissertation&rft.title=The+Power+of+Evil+Choices+in+Bloom+Filters&rft.inst=INRIA+Grenoble&rft.date=2014-11-12&rft.aulast=Gerbet&rft.aufirst=Thomas&rft.au=Kumar%2C+Amrit&rft.au=Lauradoux%2C+C%C3%A9dric&rft_id=https%3A%2F%2Fhal.inria.fr%2Fhal-01082158v2&rfr_id=info%3Asid%2Fen.wikipedia.org%3ACollision+attack" class="Z3988"></span></span> </li> </ol></div></div> <div class="mw-heading mw-heading2"><h2 id="External_links">External links</h2><span class="mw-editsection"><span class="mw-editsection-bracket">[</span><a href="/w/index.php?title=Collision_attack&action=edit&section=8" title="Edit section: External links"><span>edit</span></a><span class="mw-editsection-bracket">]</span></span></div> <ul><li><a rel="nofollow" class="external text" href="https://web.archive.org/web/20151222161723/http://www.iaik.tugraz.at/content/research/krypto/sha1/MeaningfulCollisions.php">"Meaningful Collisions", attack scenarios for exploiting cryptographic hash collisions</a></li> <li><a rel="nofollow" class="external text" href="http://www.bishopfox.com/resources/tools/other-free-tools/md4md5-collision-code/">Fast MD5 and MD4 Collision Generators</a> - Bishop Fox (formerly Stach & Liu). Create MD4 and MD5 hash collisions using groundbreaking new code that improves upon the techniques originally developed by Xiaoyun Wang. Using a 1.6 GHz Pentium 4, MD5 collisions can be generated in an average of 45 minutes, and MD4 collisions can be generated in an average of 5 seconds. Originally released on 22Jun2006.</li></ul> <div class="navbox-styles"><style data-mw-deduplicate="TemplateStyles:r1129693374">.mw-parser-output .hlist dl,.mw-parser-output .hlist ol,.mw-parser-output .hlist ul{margin:0;padding:0}.mw-parser-output .hlist dd,.mw-parser-output .hlist dt,.mw-parser-output .hlist li{margin:0;display:inline}.mw-parser-output .hlist.inline,.mw-parser-output .hlist.inline dl,.mw-parser-output .hlist.inline ol,.mw-parser-output .hlist.inline ul,.mw-parser-output .hlist dl dl,.mw-parser-output .hlist dl ol,.mw-parser-output .hlist dl ul,.mw-parser-output .hlist ol dl,.mw-parser-output .hlist ol ol,.mw-parser-output .hlist ol ul,.mw-parser-output .hlist ul dl,.mw-parser-output .hlist ul ol,.mw-parser-output .hlist ul ul{display:inline}.mw-parser-output .hlist .mw-empty-li{display:none}.mw-parser-output .hlist dt::after{content:": "}.mw-parser-output .hlist dd::after,.mw-parser-output .hlist li::after{content:" · ";font-weight:bold}.mw-parser-output .hlist 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style="padding:3px"><table class="nowraplinks hlist navbox-inner" style="border-spacing:0;background:transparent;color:inherit"><tbody><tr><td colspan="2" class="navbox-list navbox-odd" style="width:100%;padding:0"><div style="padding:0 0.25em"></div><table class="nowraplinks navbox-subgroup" style="border-spacing:0"><tbody><tr><td colspan="2" class="navbox-list navbox-odd" style="width:100%;padding:0"><div style="padding:0 0.25em"></div><table class="nowraplinks hlist mw-collapsible mw-collapsed navbox-subgroup" style="border-spacing:0"><tbody><tr><th scope="col" class="navbox-title" colspan="2"><div class="navbar plainlinks hlist navbar-mini"><ul><li class="nv-view"><a href="/wiki/Template:Cryptography_hash" title="Template:Cryptography hash"><abbr title="View this template">v</abbr></a></li><li class="nv-talk"><a href="/wiki/Template_talk:Cryptography_hash" title="Template talk:Cryptography hash"><abbr title="Discuss this template">t</abbr></a></li><li class="nv-edit"><a 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style="width:1%">Common functions</th><td class="navbox-list-with-group navbox-list navbox-odd" style="width:100%;padding:0"><div style="padding:0 0.25em"> <ul><li><a href="/wiki/MD5" title="MD5">MD5</a> (compromised)</li> <li><a href="/wiki/SHA-1" title="SHA-1">SHA-1</a> (compromised)</li> <li><a href="/wiki/SHA-2" title="SHA-2">SHA-2</a></li> <li><a href="/wiki/SHA-3" title="SHA-3">SHA-3</a></li> <li><a href="/wiki/BLAKE_(hash_function)#BLAKE2" title="BLAKE (hash function)">BLAKE2</a></li></ul> </div></td></tr><tr><th scope="row" class="navbox-group" style="width:1%"><a href="/wiki/NIST_hash_function_competition" title="NIST hash function competition">SHA-3 finalists</a></th><td class="navbox-list-with-group navbox-list navbox-even" style="width:100%;padding:0"><div style="padding:0 0.25em"> <ul><li><a href="/wiki/BLAKE_(hash_function)" title="BLAKE (hash function)">BLAKE</a></li> <li><a href="/wiki/Gr%C3%B8stl" title="Grøstl">Grøstl</a></li> <li><a href="/wiki/JH_(hash_function)" title="JH (hash function)">JH</a></li> <li><a href="/wiki/Skein_(hash_function)" title="Skein (hash function)">Skein</a></li> <li><a href="/wiki/SHA-3" title="SHA-3">Keccak</a> (winner)</li></ul> </div></td></tr><tr><th scope="row" class="navbox-group" style="width:1%">Other functions</th><td class="navbox-list-with-group navbox-list navbox-odd" style="width:100%;padding:0"><div style="padding:0 0.25em"> <ul><li><a href="/wiki/BLAKE3" class="mw-redirect" title="BLAKE3">BLAKE3</a></li> <li><a href="/wiki/CubeHash" title="CubeHash">CubeHash</a></li> <li><a href="/wiki/Elliptic_curve_only_hash" title="Elliptic curve only hash">ECOH</a></li> <li><a href="/wiki/Fast_syndrome-based_hash" title="Fast syndrome-based hash">FSB</a></li> <li><a href="/wiki/Fugue_(hash_function)" title="Fugue (hash function)">Fugue</a></li> <li><a href="/wiki/GOST_(hash_function)" title="GOST (hash function)">GOST</a></li> <li><a href="/wiki/HAS-160" title="HAS-160">HAS-160</a></li> <li><a href="/wiki/HAVAL" title="HAVAL">HAVAL</a></li> <li><a href="/wiki/Kupyna" title="Kupyna">Kupyna</a></li> <li><a href="/wiki/LSH_(hash_function)" title="LSH (hash function)">LSH</a></li> <li><a href="/wiki/Lane_(hash_function)" title="Lane (hash function)">Lane</a></li> <li><a href="/wiki/MASH-1" title="MASH-1">MASH-1</a></li> <li><a href="/wiki/MASH-1#MASH2" title="MASH-1">MASH-2</a></li> <li><a href="/wiki/MD2_(hash_function)" title="MD2 (hash function)">MD2</a></li> <li><a href="/wiki/MD4" title="MD4">MD4</a></li> <li><a href="/wiki/MD6" title="MD6">MD6</a></li> <li><a href="/wiki/MDC-2" title="MDC-2">MDC-2</a></li> <li><a href="/wiki/N-hash" title="N-hash">N-hash</a></li> <li><a href="/wiki/RIPEMD" title="RIPEMD">RIPEMD</a></li> <li><a href="/wiki/RadioGat%C3%BAn" title="RadioGatún">RadioGatún</a></li> <li><a href="/wiki/SIMD_(hash_function)" title="SIMD (hash function)">SIMD</a></li> <li><a href="/wiki/SM3_(hash_function)" title="SM3 (hash function)">SM3</a></li> <li><a href="/wiki/SWIFFT" title="SWIFFT">SWIFFT</a></li> <li><a href="/wiki/Shabal" title="Shabal">Shabal</a></li> <li><a href="/wiki/Snefru" title="Snefru">Snefru</a></li> <li><a href="/wiki/Streebog" title="Streebog">Streebog</a></li> <li><a href="/wiki/Tiger_(hash_function)" title="Tiger (hash function)">Tiger</a></li> <li><a href="/wiki/Very_smooth_hash" title="Very smooth hash">VSH</a></li> <li><a href="/wiki/Whirlpool_(hash_function)" title="Whirlpool (hash function)">Whirlpool</a></li></ul> </div></td></tr><tr><th scope="row" class="navbox-group" style="width:1%">Password hashing/<br /><a href="/wiki/Key_stretching" title="Key stretching">key stretching</a> functions</th><td class="navbox-list-with-group navbox-list navbox-even" style="width:100%;padding:0"><div style="padding:0 0.25em"> <ul><li><a href="/wiki/Argon2" title="Argon2">Argon2</a></li> <li><a href="/wiki/Balloon_hashing" title="Balloon hashing">Balloon</a></li> <li><a href="/wiki/Bcrypt" title="Bcrypt">bcrypt</a></li> <li><a href="/wiki/Catena_(cryptography)" class="mw-redirect" title="Catena (cryptography)">Catena</a></li> <li><a href="/wiki/Crypt_(C)" title="Crypt (C)">crypt</a></li> <li><a href="/wiki/LAN_Manager#LM_hash_details" title="LAN Manager">LM hash</a></li> <li><a href="/wiki/Lyra2" title="Lyra2">Lyra2</a></li> <li><a href="/wiki/Makwa_(cryptography)" class="mw-redirect" title="Makwa (cryptography)">Makwa</a></li> <li><a href="/wiki/PBKDF2" title="PBKDF2">PBKDF2</a></li> <li><a href="/wiki/Scrypt" title="Scrypt">scrypt</a></li> <li><a href="/wiki/Yescrypt" title="Yescrypt">yescrypt</a></li></ul> </div></td></tr><tr><th scope="row" class="navbox-group" style="width:1%">General purpose<br /><a href="/wiki/Key_derivation_function" title="Key derivation function">key derivation functions</a></th><td class="navbox-list-with-group navbox-list navbox-odd" style="width:100%;padding:0"><div style="padding:0 0.25em"> <ul><li><a href="/wiki/HKDF" title="HKDF">HKDF</a></li> <li>KDF1/KDF2</li></ul> </div></td></tr><tr><th scope="row" class="navbox-group" style="width:1%"><a href="/wiki/Message_authentication_code" title="Message authentication code">MAC functions</a></th><td class="navbox-list-with-group navbox-list navbox-even" style="width:100%;padding:0"><div style="padding:0 0.25em"> <ul><li><a href="/wiki/CBC-MAC" title="CBC-MAC">CBC-MAC</a></li> <li><a href="/wiki/Data_Authentication_Algorithm" title="Data Authentication Algorithm">DAA</a></li> <li><a href="/wiki/Galois_Message_Authentication_Code" class="mw-redirect" title="Galois Message Authentication Code">GMAC</a></li> <li><a href="/wiki/HMAC" title="HMAC">HMAC</a></li> <li><a href="/wiki/NMAC" class="mw-redirect" title="NMAC">NMAC</a></li> <li><a href="/wiki/One-key_MAC" title="One-key MAC">OMAC</a>/<a href="/wiki/One-key_MAC" title="One-key MAC">CMAC</a></li> <li><a href="/wiki/PMAC_(cryptography)" title="PMAC (cryptography)">PMAC</a></li> <li><a href="/wiki/Poly1305" title="Poly1305">Poly1305</a></li> <li><a href="/wiki/SipHash" title="SipHash">SipHash</a></li> <li><a href="/wiki/UMAC_(cryptography)" title="UMAC (cryptography)">UMAC</a></li> <li><a href="/wiki/VMAC" title="VMAC">VMAC</a></li></ul> </div></td></tr><tr><th scope="row" class="navbox-group" style="width:1%"><a href="/wiki/Authenticated_encryption" title="Authenticated encryption">Authenticated<br />encryption</a> modes</th><td class="navbox-list-with-group navbox-list navbox-odd" style="width:100%;padding:0"><div style="padding:0 0.25em"> <ul><li><a href="/wiki/CCM_mode" title="CCM mode">CCM</a></li> <li><a href="/wiki/ChaCha20-Poly1305" title="ChaCha20-Poly1305">ChaCha20-Poly1305</a></li> <li><a href="/wiki/CWC_mode" title="CWC mode">CWC</a></li> <li><a href="/wiki/EAX_mode" title="EAX mode">EAX</a></li> <li><a href="/wiki/Galois/Counter_Mode" title="Galois/Counter Mode">GCM</a></li> <li><a href="/wiki/IAPM_(mode)" title="IAPM (mode)">IAPM</a></li> <li><a href="/wiki/OCB_mode" title="OCB mode">OCB</a></li></ul> </div></td></tr><tr><th scope="row" class="navbox-group" style="width:1%">Attacks</th><td class="navbox-list-with-group navbox-list navbox-even" style="width:100%;padding:0"><div style="padding:0 0.25em"> <ul><li><a class="mw-selflink selflink">Collision attack</a></li> <li><a href="/wiki/Preimage_attack" title="Preimage attack">Preimage attack</a></li> <li><a href="/wiki/Birthday_attack" title="Birthday attack">Birthday attack</a></li> <li><a href="/wiki/Brute-force_attack" title="Brute-force attack">Brute-force attack</a></li> <li><a href="/wiki/Rainbow_table" title="Rainbow table">Rainbow table</a></li> <li><a href="/wiki/Side-channel_attack" title="Side-channel attack">Side-channel attack</a></li> <li><a href="/wiki/Length_extension_attack" title="Length extension attack">Length extension attack</a></li></ul> </div></td></tr><tr><th scope="row" class="navbox-group" style="width:1%">Design</th><td class="navbox-list-with-group navbox-list navbox-odd" style="width:100%;padding:0"><div style="padding:0 0.25em"> <ul><li><a href="/wiki/Avalanche_effect" title="Avalanche effect">Avalanche effect</a></li> <li><a href="/wiki/Hash_collision" title="Hash collision">Hash collision</a></li> <li><a href="/wiki/Merkle%E2%80%93Damg%C3%A5rd_construction" title="Merkle–Damgård construction">Merkle–Damgård construction</a></li> <li><a href="/wiki/Sponge_function" title="Sponge function">Sponge function</a></li> <li><a href="/wiki/HAIFA_construction" title="HAIFA construction">HAIFA construction</a></li></ul> </div></td></tr><tr><th scope="row" class="navbox-group" style="width:1%">Standardization</th><td class="navbox-list-with-group navbox-list navbox-even" style="width:100%;padding:0"><div style="padding:0 0.25em"> <ul><li><a href="/wiki/CAESAR_Competition" title="CAESAR Competition">CAESAR Competition</a></li> <li><a href="/wiki/CRYPTREC" title="CRYPTREC">CRYPTREC</a></li> <li><a href="/wiki/NESSIE" title="NESSIE">NESSIE</a></li> <li><a href="/wiki/NIST_hash_function_competition" title="NIST hash function competition">NIST hash function competition</a></li> <li><a href="/wiki/Password_Hashing_Competition" title="Password Hashing Competition">Password Hashing Competition</a></li> <li><a href="/wiki/NSA_Suite_B_Cryptography" title="NSA Suite B Cryptography">NSA Suite B</a></li> <li><a href="/wiki/Commercial_National_Security_Algorithm_Suite" title="Commercial National Security Algorithm Suite">CNSA</a></li></ul> </div></td></tr><tr><th scope="row" class="navbox-group" style="width:1%">Utilization</th><td class="navbox-list-with-group navbox-list navbox-odd" style="width:100%;padding:0"><div style="padding:0 0.25em"> <ul><li><a href="/wiki/Post-quantum_cryptography#Hash-based_cryptography" title="Post-quantum cryptography">Hash-based cryptography</a></li> <li><a href="/wiki/Merkle_tree" title="Merkle tree">Merkle tree</a></li> <li><a href="/wiki/Message_authentication" title="Message authentication">Message authentication</a></li> <li><a href="/wiki/Proof_of_work" title="Proof of work">Proof of work</a></li> <li><a href="/wiki/Salt_(cryptography)" title="Salt (cryptography)">Salt</a></li> <li><a href="/wiki/Pepper_(cryptography)" title="Pepper (cryptography)">Pepper</a></li></ul> </div></td></tr></tbody></table><div></div></td></tr></tbody></table><div></div></td></tr><tr><td colspan="2" class="navbox-list navbox-odd" style="width:100%;padding:0"><div style="padding:0 0.25em"></div><table class="nowraplinks mw-collapsible mw-collapsed navbox-subgroup" style="border-spacing:0"><tbody><tr><th scope="col" class="navbox-title" colspan="2"><div class="navbar plainlinks hlist navbar-mini"><ul><li class="nv-view"><a href="/wiki/Template:Cryptography_navbox" title="Template:Cryptography navbox"><abbr title="View this template">v</abbr></a></li><li class="nv-talk"><a href="/wiki/Template_talk:Cryptography_navbox" title="Template talk:Cryptography navbox"><abbr title="Discuss this template">t</abbr></a></li><li class="nv-edit"><a href="/wiki/Special:EditPage/Template:Cryptography_navbox" title="Special:EditPage/Template:Cryptography navbox"><abbr title="Edit this template">e</abbr></a></li></ul></div><div id="Cryptography149" style="font-size:114%;margin:0 4em"><a href="/wiki/Cryptography" title="Cryptography">Cryptography</a></div></th></tr><tr><th scope="row" class="navbox-group" style="width:1%">General</th><td class="navbox-list-with-group navbox-list navbox-odd" style="width:100%;padding:0"><div style="padding:0 0.25em"> <ul><li><a href="/wiki/History_of_cryptography" title="History of cryptography">History of cryptography</a></li> <li><a href="/wiki/Outline_of_cryptography" title="Outline of cryptography">Outline of cryptography</a></li> <li><a href="/wiki/Classical_cipher" title="Classical cipher">Classical cipher</a></li> <li><a href="/wiki/Cryptographic_protocol" title="Cryptographic protocol">Cryptographic protocol</a> <ul><li><a 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title="Secure Hash Algorithms">Secure Hash Algorithms</a></li></ul></li> <li><a href="/wiki/Digital_signature" title="Digital signature">Digital signature</a></li> <li><a href="/wiki/Kleptography" title="Kleptography">Kleptography</a></li> <li><a href="/wiki/Key_(cryptography)" title="Key (cryptography)">Key (cryptography)</a></li> <li><a href="/wiki/Key_exchange" title="Key exchange">Key exchange</a></li> <li><a href="/wiki/Key_generator" title="Key generator">Key generator</a></li> <li><a href="/wiki/Key_schedule" title="Key schedule">Key schedule</a></li> <li><a href="/wiki/Key_stretching" title="Key stretching">Key stretching</a></li> <li><a href="/wiki/Keygen" title="Keygen">Keygen</a></li> <li><a href="/wiki/Template:Cryptography_machines" title="Template:Cryptography machines">Machines</a></li> <li><a href="/wiki/Cryptojacking_malware" class="mw-redirect" title="Cryptojacking malware">Cryptojacking malware</a></li> <li><a href="/wiki/Ransomware" 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