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Available in 16 languages" > <label id="p-lang-btn-label" for="p-lang-btn-checkbox" class="vector-dropdown-label cdx-button cdx-button--fake-button cdx-button--fake-button--enabled cdx-button--weight-quiet cdx-button--action-progressive mw-portlet-lang-heading-16" aria-hidden="true" ><span class="vector-icon mw-ui-icon-language-progressive mw-ui-icon-wikimedia-language-progressive"></span> <span class="vector-dropdown-label-text">16 languages</span> </label> <div class="vector-dropdown-content"> <div class="vector-menu-content"> <ul class="vector-menu-content-list"> <li class="interlanguage-link interwiki-ar mw-list-item"><a href="https://ar.wikipedia.org/wiki/%D8%A7%D9%84%D8%B1%D9%82%D9%85_%D8%A7%D9%84%D8%AE%D8%A7%D8%B5" title="الرقم الخاص – Arabic" lang="ar" hreflang="ar" data-title="الرقم الخاص" data-language-autonym="العربية" data-language-local-name="Arabic" class="interlanguage-link-target"><span>العربية</span></a></li><li class="interlanguage-link interwiki-zh-min-nan mw-list-item"><a href="https://zh-min-nan.wikipedia.org/wiki/Nonce" title="Nonce – Minnan" lang="nan" hreflang="nan" data-title="Nonce" data-language-autonym="閩南語 / Bân-lâm-gú" data-language-local-name="Minnan" class="interlanguage-link-target"><span>閩南語 / Bân-lâm-gú</span></a></li><li class="interlanguage-link interwiki-ca mw-list-item"><a href="https://ca.wikipedia.org/wiki/Nonce_(criptografia)" title="Nonce (criptografia) – Catalan" lang="ca" hreflang="ca" data-title="Nonce (criptografia)" data-language-autonym="Català" data-language-local-name="Catalan" class="interlanguage-link-target"><span>Català</span></a></li><li class="interlanguage-link interwiki-cs mw-list-item"><a href="https://cs.wikipedia.org/wiki/Kryptografick%C3%A1_nonce" title="Kryptografická nonce – Czech" lang="cs" hreflang="cs" data-title="Kryptografická nonce" 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/Nonce" title="Nonce – German" lang="de" hreflang="de" data-title="Nonce" 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/Nonce" title="Nonce – Spanish" lang="es" hreflang="es" data-title="Nonce" data-language-autonym="Español" data-language-local-name="Spanish" class="interlanguage-link-target"><span>Español</span></a></li><li class="interlanguage-link interwiki-fa mw-list-item"><a href="https://fa.wikipedia.org/wiki/%D8%B1%D9%85%D8%B2%D9%86%DA%AF%D8%A7%D8%B1%DB%8C_%D9%86%D8%A7%D9%86%D8%B3" title="رمزنگاری نانس – Persian" lang="fa" hreflang="fa" data-title="رمزنگاری نانس" data-language-autonym="فارسی" data-language-local-name="Persian" class="interlanguage-link-target"><span>فارسی</span></a></li><li class="interlanguage-link interwiki-fr mw-list-item"><a href="https://fr.wikipedia.org/wiki/Nonce_(cryptographie)" title="Nonce (cryptographie) – French" lang="fr" hreflang="fr" data-title="Nonce (cryptographie)" data-language-autonym="Français" data-language-local-name="French" class="interlanguage-link-target"><span>Français</span></a></li><li class="interlanguage-link interwiki-it mw-list-item"><a href="https://it.wikipedia.org/wiki/Nonce" title="Nonce – Italian" lang="it" hreflang="it" data-title="Nonce" data-language-autonym="Italiano" data-language-local-name="Italian" class="interlanguage-link-target"><span>Italiano</span></a></li><li class="interlanguage-link interwiki-lv mw-list-item"><a href="https://lv.wikipedia.org/wiki/Vienreiz%C4%93jais_kods" title="Vienreizējais kods – Latvian" lang="lv" hreflang="lv" data-title="Vienreizējais kods" data-language-autonym="Latviešu" data-language-local-name="Latvian" class="interlanguage-link-target"><span>Latviešu</span></a></li><li class="interlanguage-link interwiki-ja mw-list-item"><a href="https://ja.wikipedia.org/wiki/%E3%83%8E%E3%83%B3%E3%82%B9" title="ノンス – Japanese" lang="ja" hreflang="ja" data-title="ノンス" data-language-autonym="日本語" data-language-local-name="Japanese" class="interlanguage-link-target"><span>日本語</span></a></li><li class="interlanguage-link interwiki-pt mw-list-item"><a href="https://pt.wikipedia.org/wiki/Nonce" title="Nonce – Portuguese" lang="pt" hreflang="pt" data-title="Nonce" data-language-autonym="Português" data-language-local-name="Portuguese" class="interlanguage-link-target"><span>Português</span></a></li><li class="interlanguage-link interwiki-ru mw-list-item"><a href="https://ru.wikipedia.org/wiki/Nonce" title="Nonce – Russian" lang="ru" hreflang="ru" data-title="Nonce" data-language-autonym="Русский" data-language-local-name="Russian" class="interlanguage-link-target"><span>Русский</span></a></li><li class="interlanguage-link interwiki-uk mw-list-item"><a href="https://uk.wikipedia.org/wiki/%D0%9A%D1%80%D0%B8%D0%BF%D1%82%D0%BE%D0%B3%D1%80%D0%B0%D1%84%D1%96%D1%87%D0%BD%D0%B8%D0%B9_%D0%BD%D0%BE%D0%BD%D1%81" title="Криптографічний нонс – Ukrainian" lang="uk" hreflang="uk" data-title="Криптографічний нонс" data-language-autonym="Українська" data-language-local-name="Ukrainian" class="interlanguage-link-target"><span>Українська</span></a></li><li class="interlanguage-link interwiki-zh-yue mw-list-item"><a href="https://zh-yue.wikipedia.org/wiki/Nonce" title="Nonce – Cantonese" lang="yue" hreflang="yue" data-title="Nonce" data-language-autonym="粵語" data-language-local-name="Cantonese" class="interlanguage-link-target"><span>粵語</span></a></li><li class="interlanguage-link interwiki-zh mw-list-item"><a href="https://zh.wikipedia.org/wiki/Nonce" title="Nonce – Chinese" lang="zh" hreflang="zh" data-title="Nonce" data-language-autonym="中文" data-language-local-name="Chinese" class="interlanguage-link-target"><span>中文</span></a></li> </ul> <div 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class="mw-body-content"><div class="mw-content-ltr mw-parser-output" lang="en" dir="ltr"><div class="shortdescription nomobile noexcerpt noprint searchaux" style="display:none">Concept in cryptography</div> <style data-mw-deduplicate="TemplateStyles:r1251242444">.mw-parser-output .ambox{border:1px solid #a2a9b1;border-left:10px solid #36c;background-color:#fbfbfb;box-sizing:border-box}.mw-parser-output .ambox+link+.ambox,.mw-parser-output .ambox+link+style+.ambox,.mw-parser-output .ambox+link+link+.ambox,.mw-parser-output .ambox+.mw-empty-elt+link+.ambox,.mw-parser-output .ambox+.mw-empty-elt+link+style+.ambox,.mw-parser-output .ambox+.mw-empty-elt+link+link+.ambox{margin-top:-1px}html body.mediawiki .mw-parser-output .ambox.mbox-small-left{margin:4px 1em 4px 0;overflow:hidden;width:238px;border-collapse:collapse;font-size:88%;line-height:1.25em}.mw-parser-output .ambox-speedy{border-left:10px solid #b32424;background-color:#fee7e6}.mw-parser-output .ambox-delete{border-left:10px solid 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href="/wiki/File:Question_book-new.svg" class="mw-file-description"><img alt="" src="//upload.wikimedia.org/wikipedia/en/thumb/9/99/Question_book-new.svg/50px-Question_book-new.svg.png" decoding="async" width="50" height="39" class="mw-file-element" srcset="//upload.wikimedia.org/wikipedia/en/thumb/9/99/Question_book-new.svg/75px-Question_book-new.svg.png 1.5x, //upload.wikimedia.org/wikipedia/en/thumb/9/99/Question_book-new.svg/100px-Question_book-new.svg.png 2x" data-file-width="512" data-file-height="399" /></a></span></div></td><td class="mbox-text"><div class="mbox-text-span">This article <b>needs additional citations for <a href="/wiki/Wikipedia:Verifiability" title="Wikipedia:Verifiability">verification</a></b>.<span class="hide-when-compact"> Relevant discussion may be found on the <a href="/wiki/Talk:Cryptographic_nonce#Citations_Lacking" title="Talk:Cryptographic nonce">talk page</a>. Please help <a href="/wiki/Special:EditPage/Cryptographic_nonce" title="Special:EditPage/Cryptographic nonce">improve this article</a> by <a href="/wiki/Help:Referencing_for_beginners" title="Help:Referencing for beginners">adding citations to reliable sources</a>. Unsourced material may be challenged and removed.<br /><small><span class="plainlinks"><i>Find sources:</i> <a rel="nofollow" class="external text" href="https://www.google.com/search?as_eq=wikipedia&q=%22Cryptographic+nonce%22">"Cryptographic nonce"</a> – <a rel="nofollow" class="external text" href="https://www.google.com/search?tbm=nws&q=%22Cryptographic+nonce%22+-wikipedia&tbs=ar:1">news</a> <b>·</b> <a rel="nofollow" class="external text" href="https://www.google.com/search?&q=%22Cryptographic+nonce%22&tbs=bkt:s&tbm=bks">newspapers</a> <b>·</b> <a rel="nofollow" class="external text" href="https://www.google.com/search?tbs=bks:1&q=%22Cryptographic+nonce%22+-wikipedia">books</a> <b>·</b> <a rel="nofollow" class="external text" href="https://scholar.google.com/scholar?q=%22Cryptographic+nonce%22">scholar</a> <b>·</b> <a rel="nofollow" class="external text" href="https://www.jstor.org/action/doBasicSearch?Query=%22Cryptographic+nonce%22&acc=on&wc=on">JSTOR</a></span></small></span> <span class="date-container"><i>(<span class="date">November 2013</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> <figure class="mw-default-size" typeof="mw:File/Thumb"><a href="/wiki/File:Nonce-cnonce-uml.svg" class="mw-file-description"><img src="//upload.wikimedia.org/wikipedia/commons/thumb/4/4f/Nonce-cnonce-uml.svg/220px-Nonce-cnonce-uml.svg.png" decoding="async" width="220" height="211" class="mw-file-element" srcset="//upload.wikimedia.org/wikipedia/commons/thumb/4/4f/Nonce-cnonce-uml.svg/330px-Nonce-cnonce-uml.svg.png 1.5x, //upload.wikimedia.org/wikipedia/commons/thumb/4/4f/Nonce-cnonce-uml.svg/440px-Nonce-cnonce-uml.svg.png 2x" data-file-width="345" data-file-height="331" /></a><figcaption>Typical client–server communication during a nonce-based <a href="/wiki/Authentication" title="Authentication">authentication</a> process including both a server nonce and a client nonce</figcaption></figure> <p>In <a href="/wiki/Cryptography" title="Cryptography">cryptography</a>, a <b>nonce</b> is an arbitrary number that can be used just once in a cryptographic communication.<sup id="cite_ref-1" class="reference"><a href="#cite_note-1"><span class="cite-bracket">[</span>1<span class="cite-bracket">]</span></a></sup> It is often a <a href="/wiki/Randomness" title="Randomness">random</a> or <a href="/wiki/Pseudorandomness" title="Pseudorandomness">pseudo-random</a> number issued in an <a href="/wiki/Authentication_protocol" title="Authentication protocol">authentication protocol</a> to ensure that each communication session is unique, and therefore that old communications cannot be reused in <a href="/wiki/Replay_attack" title="Replay attack">replay attacks</a>. Nonces can also be useful as <a href="/wiki/Initialization_vector" title="Initialization vector">initialization vectors</a> and in <a href="/wiki/Cryptographic_hash_functions" class="mw-redirect" title="Cryptographic hash functions">cryptographic hash functions</a>. </p> <meta property="mw:PageProp/toc" /> <div class="mw-heading mw-heading2"><h2 id="Definition">Definition</h2><span class="mw-editsection"><span class="mw-editsection-bracket">[</span><a href="/w/index.php?title=Cryptographic_nonce&action=edit&section=1" title="Edit section: Definition"><span>edit</span></a><span class="mw-editsection-bracket">]</span></span></div> <p>A nonce is an arbitrary number used only once in a cryptographic communication, in the spirit of a <a href="/wiki/Nonce_word" title="Nonce word">nonce word</a>. They are often <a href="/wiki/Randomness" title="Randomness">random</a> or <a href="/wiki/Pseudo-random" class="mw-redirect" title="Pseudo-random">pseudo-random</a> numbers. Many nonces also include a <a href="/wiki/Timestamp" title="Timestamp">timestamp</a> to ensure exact timeliness, though this requires <a href="/wiki/Clock_synchronisation" class="mw-redirect" title="Clock synchronisation">clock synchronisation</a> between organisations. The addition of a client nonce ("<b>cnonce</b>") helps to improve the security in some ways as implemented in <a href="/wiki/Digest_access_authentication" title="Digest access authentication">digest access authentication</a>. To ensure that a nonce is used only once, it should be time-variant (including a suitably fine-grained timestamp in its value), or generated with enough random bits to ensure an insignificantly low chance of repeating a previously generated value. Some authors define pseudo-randomness (or unpredictability) as a requirement for a nonce.<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> </p><p>Nonce is a word dating back to Middle English for something only used once or temporarily (often with the construction "for the nonce"). It descends from the construction "then anes" ("the one [purpose]").<sup id="cite_ref-ODE_3-0" class="reference"><a href="#cite_note-ODE-3"><span class="cite-bracket">[</span>3<span class="cite-bracket">]</span></a></sup> A <a href="/wiki/False_etymology" title="False etymology">false etymology</a> claiming it to mean "number used once" is incorrect.<sup id="cite_ref-4" class="reference"><a href="#cite_note-4"><span class="cite-bracket">[</span>4<span class="cite-bracket">]</span></a></sup> In Britain the term may be avoided as "nonce" in modern <a href="/wiki/British_English" title="British English">British English</a> means a paedophile.<sup id="cite_ref-ODE_3-1" class="reference"><a href="#cite_note-ODE-3"><span class="cite-bracket">[</span>3<span class="cite-bracket">]</span></a></sup><sup id="cite_ref-5" class="reference"><a href="#cite_note-5"><span class="cite-bracket">[</span>5<span class="cite-bracket">]</span></a></sup> </p> <div class="mw-heading mw-heading2"><h2 id="Usage">Usage</h2><span class="mw-editsection"><span class="mw-editsection-bracket">[</span><a href="/w/index.php?title=Cryptographic_nonce&action=edit&section=2" title="Edit section: Usage"><span>edit</span></a><span class="mw-editsection-bracket">]</span></span></div> <div class="mw-heading mw-heading3"><h3 id="Authentication">Authentication</h3><span class="mw-editsection"><span class="mw-editsection-bracket">[</span><a href="/w/index.php?title=Cryptographic_nonce&action=edit&section=3" title="Edit section: Authentication"><span>edit</span></a><span class="mw-editsection-bracket">]</span></span></div> <p><a href="/wiki/Authentication_protocol" title="Authentication protocol">Authentication protocols</a> may use nonces to ensure that old communications cannot be reused in <a href="/wiki/Replay_attack" title="Replay attack">replay attacks</a>. For instance, nonces are used in <a href="/wiki/HTTP" title="HTTP">HTTP</a> <a href="/wiki/Digest_access_authentication" title="Digest access authentication">digest access authentication</a> to calculate an <a href="/wiki/MD5" title="MD5">MD5</a> digest of the <a href="/wiki/Password" title="Password">password</a>. The nonces are different each time the 401 authentication challenge <a href="/wiki/List_of_HTTP_status_codes" title="List of HTTP status codes">response code</a> is presented, thus making <a href="/wiki/Replay_attack" title="Replay attack">replay attacks</a> virtually impossible. The scenario of ordering products over the Internet can provide an example of the usefulness of nonces in replay attacks. An attacker could take the encrypted information and—without needing to decrypt—could continue to send a particular order to the supplier, thereby ordering products over and over again under the same name and purchase information. The nonce is used to give 'originality' to a given message so that if the company receives any other orders from the same person with the same nonce, it will discard those as invalid orders. </p><p>A nonce may be used to ensure security for a <a href="/wiki/Stream_cipher" title="Stream cipher">stream cipher</a>. Where the same key is used for more than one message and then a different nonce is used to ensure that the <a href="/wiki/Keystream" title="Keystream">keystream</a> is different for different messages encrypted with that key; often the message number is used. </p><p>Secret nonce values are used by the <a href="/wiki/Lamport_signature" title="Lamport signature">Lamport signature</a> scheme as a signer-side secret which can be selectively revealed for comparison to public hashes for signature creation and verification. </p> <div class="mw-heading mw-heading3"><h3 id="Initialization_vectors">Initialization vectors</h3><span class="mw-editsection"><span class="mw-editsection-bracket">[</span><a href="/w/index.php?title=Cryptographic_nonce&action=edit&section=4" title="Edit section: Initialization vectors"><span>edit</span></a><span class="mw-editsection-bracket">]</span></span></div> <p><a href="/wiki/Initialization_vector" title="Initialization vector">Initialization vectors</a> may be referred to as nonces, as they are typically random or pseudo-random. </p> <div class="mw-heading mw-heading3"><h3 id="Hashing">Hashing</h3><span class="mw-editsection"><span class="mw-editsection-bracket">[</span><a href="/w/index.php?title=Cryptographic_nonce&action=edit&section=5" title="Edit section: Hashing"><span>edit</span></a><span class="mw-editsection-bracket">]</span></span></div> <p>Nonces are used in <a href="/wiki/Proof-of-work_system" class="mw-redirect" title="Proof-of-work system">proof-of-work systems</a> to vary the input to a <a href="/wiki/Cryptographic_hash_function" title="Cryptographic hash function">cryptographic hash function</a> so as to obtain a hash for a certain input that fulfils certain arbitrary conditions. In doing so, it becomes far more difficult to create a "desirable" hash than to verify it, shifting the burden of work onto one side of a transaction or system. For example, proof of work, using hash functions, was considered as a means to combat <a href="/wiki/Email_spam" title="Email spam">email spam</a> by forcing email senders to find a hash value for the email (which included a timestamp to prevent pre-computation of useful hashes for later use) that had an arbitrary number of leading zeroes, by hashing the same input with a large number of values until a "desirable" hash was obtained. </p><p>Similarly, the <a href="/wiki/Bitcoin" title="Bitcoin">Bitcoin</a> <a href="/wiki/Blockchain" title="Blockchain">blockchain</a> hashing algorithm can be tuned to an arbitrary difficulty by changing the required minimum/maximum value of the hash so that the number of bitcoins awarded for new blocks does not increase linearly with increased network computation power as new users join. This is likewise achieved by forcing Bitcoin miners to add nonce values to the value being hashed to change the hash algorithm output. As cryptographic hash algorithms cannot easily be predicted based on their inputs, this makes the act of blockchain hashing and the possibility of being awarded bitcoins something of a lottery, where the first "miner" to find a nonce that delivers a desirable hash is awarded bitcoins. </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=Cryptographic_nonce&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/Key_stretching" title="Key stretching">Key stretching</a></li> <li><a href="/wiki/Salt_(cryptography)" title="Salt (cryptography)">Salt (cryptography)</a></li> <li><a href="/wiki/Nonce_word" title="Nonce word">Nonce word</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=Cryptographic_nonce&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"><ol class="references"> <li id="cite_note-1"><span class="mw-cite-backlink"><b><a href="#cite_ref-1">^</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 class="citation web cs1"><a rel="nofollow" class="external text" href="https://csrc.nist.gov/glossary/term/nonce">"nonce - Glossary | CSRC"</a>. <i>csrc.nist.gov</i>. <a href="/wiki/National_Institute_of_Standards_and_Technology" title="National Institute of Standards and Technology">National Institute of Standards and Technology</a><span class="reference-accessdate">. Retrieved <span class="nowrap">2021-10-24</span></span>.</cite><span title="ctx_ver=Z39.88-2004&rft_val_fmt=info%3Aofi%2Ffmt%3Akev%3Amtx%3Ajournal&rft.genre=unknown&rft.jtitle=csrc.nist.gov&rft.atitle=nonce+-+Glossary+%7C+CSRC&rft_id=https%3A%2F%2Fcsrc.nist.gov%2Fglossary%2Fterm%2Fnonce&rfr_id=info%3Asid%2Fen.wikipedia.org%3ACryptographic+nonce" class="Z3988"></span></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"><link rel="mw-deduplicated-inline-style" href="mw-data:TemplateStyles:r1238218222"><cite id="CITEREFRogaway2004" class="citation book cs1">Rogaway, P. (2004). <a rel="nofollow" class="external text" href="http://www.cs.ucdavis.edu/~rogaway/papers/nonce.pdf">"Nonce-Based Symmetric Encryption"</a> <span class="cs1-format">(PDF)</span>. In Bimal Roy; Willi Meier (eds.). <i>Fast Software Encryption</i>. Lecture Notes in Computer Science. Vol. 3017. pp. 348–358. <a href="/wiki/Doi_(identifier)" class="mw-redirect" title="Doi (identifier)">doi</a>:<a rel="nofollow" class="external text" href="https://doi.org/10.1007%2F978-3-540-25937-4_22">10.1007/978-3-540-25937-4_22</a>. <a href="/wiki/ISBN_(identifier)" class="mw-redirect" title="ISBN (identifier)">ISBN</a> <a href="/wiki/Special:BookSources/978-3-540-25937-4" title="Special:BookSources/978-3-540-25937-4"><bdi>978-3-540-25937-4</bdi></a>.</cite><span title="ctx_ver=Z39.88-2004&rft_val_fmt=info%3Aofi%2Ffmt%3Akev%3Amtx%3Abook&rft.genre=bookitem&rft.atitle=Nonce-Based+Symmetric+Encryption&rft.btitle=Fast+Software+Encryption&rft.series=Lecture+Notes+in+Computer+Science&rft.pages=348-358&rft.date=2004&rft_id=info%3Adoi%2F10.1007%2F978-3-540-25937-4_22&rft.isbn=978-3-540-25937-4&rft.aulast=Rogaway&rft.aufirst=P.&rft_id=http%3A%2F%2Fwww.cs.ucdavis.edu%2F~rogaway%2Fpapers%2Fnonce.pdf&rfr_id=info%3Asid%2Fen.wikipedia.org%3ACryptographic+nonce" class="Z3988"></span></span> </li> <li id="cite_note-ODE-3"><span class="mw-cite-backlink">^ <a href="#cite_ref-ODE_3-0"><sup><i><b>a</b></i></sup></a> <a href="#cite_ref-ODE_3-1"><sup><i><b>b</b></i></sup></a></span> <span class="reference-text"><link rel="mw-deduplicated-inline-style" href="mw-data:TemplateStyles:r1238218222"><cite class="citation book cs1"><i>Oxford Dictionary of English [version included with macOS]</i>. Oxford University Press. 2021. <q>Middle English: from then anes 'the one (purpose') (from then, obsolete oblique form of the + ane 'one' + -s), altered by wrong division</q></cite><span title="ctx_ver=Z39.88-2004&rft_val_fmt=info%3Aofi%2Ffmt%3Akev%3Amtx%3Abook&rft.genre=book&rft.btitle=Oxford+Dictionary+of+English+%5Bversion+included+with+macOS%5D&rft.pub=Oxford+University+Press&rft.date=2021&rfr_id=info%3Asid%2Fen.wikipedia.org%3ACryptographic+nonce" class="Z3988"></span></span> </li> <li id="cite_note-4"><span class="mw-cite-backlink"><b><a href="#cite_ref-4">^</a></b></span> <span class="reference-text"><link rel="mw-deduplicated-inline-style" href="mw-data:TemplateStyles:r1238218222"><cite id="CITEREFNeedhamSchroeder1978" class="citation journal cs1">Needham, Roger M.; Schroeder, Michael D. (1978-12-01). <a rel="nofollow" class="external text" href="https://dl.acm.org/doi/10.1145/359657.359659">"Using encryption for authentication in large networks of computers"</a>. <i>Communications of the ACM</i>. <b>21</b> (12): 993–999. <a href="/wiki/Doi_(identifier)" class="mw-redirect" title="Doi (identifier)">doi</a>:<a rel="nofollow" class="external text" href="https://doi.org/10.1145%2F359657.359659">10.1145/359657.359659</a>. <a href="/wiki/ISSN_(identifier)" class="mw-redirect" title="ISSN (identifier)">ISSN</a> <a rel="nofollow" class="external text" href="https://search.worldcat.org/issn/0001-0782">0001-0782</a>.</cite><span title="ctx_ver=Z39.88-2004&rft_val_fmt=info%3Aofi%2Ffmt%3Akev%3Amtx%3Ajournal&rft.genre=article&rft.jtitle=Communications+of+the+ACM&rft.atitle=Using+encryption+for+authentication+in+large+networks+of+computers&rft.volume=21&rft.issue=12&rft.pages=993-999&rft.date=1978-12-01&rft_id=info%3Adoi%2F10.1145%2F359657.359659&rft.issn=0001-0782&rft.aulast=Needham&rft.aufirst=Roger+M.&rft.au=Schroeder%2C+Michael+D.&rft_id=https%3A%2F%2Fdl.acm.org%2Fdoi%2F10.1145%2F359657.359659&rfr_id=info%3Asid%2Fen.wikipedia.org%3ACryptographic+nonce" class="Z3988"></span></span> </li> <li id="cite_note-5"><span class="mw-cite-backlink"><b><a href="#cite_ref-5">^</a></b></span> <span class="reference-text"><link rel="mw-deduplicated-inline-style" href="mw-data:TemplateStyles:r1238218222"><cite class="citation cs2"><a class="external text" href="https://en.wiktionary.org/w/index.php?title=nonce&oldid=78766197">"nonce"</a>, <i>Wiktionary, the free dictionary</i>, 2024-04-06<span class="reference-accessdate">, retrieved <span class="nowrap">2024-04-15</span></span></cite><span title="ctx_ver=Z39.88-2004&rft_val_fmt=info%3Aofi%2Ffmt%3Akev%3Amtx%3Ajournal&rft.genre=article&rft.jtitle=Wiktionary%2C+the+free+dictionary&rft.atitle=nonce&rft.date=2024-04-06&rft_id=https%3A%2F%2Fen.wiktionary.org%2Fw%2Findex.php%3Ftitle%3Dnonce%26oldid%3D78766197&rfr_id=info%3Asid%2Fen.wikipedia.org%3ACryptographic+nonce" 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=Cryptographic_nonce&action=edit&section=8" title="Edit section: External links"><span>edit</span></a><span class="mw-editsection-bracket">]</span></span></div> <ul><li><link rel="mw-deduplicated-inline-style" href="mw-data:TemplateStyles:r1238218222"><a href="/wiki/RFC_(identifier)" class="mw-redirect" title="RFC (identifier)">RFC</a> <a rel="nofollow" class="external text" href="https://datatracker.ietf.org/doc/html/rfc2617">2617</a> – HTTP Authentication: Basic and Digest Access Authentication</li> <li><link rel="mw-deduplicated-inline-style" href="mw-data:TemplateStyles:r1238218222"><a href="/wiki/RFC_(identifier)" class="mw-redirect" title="RFC (identifier)">RFC</a> <a rel="nofollow" class="external text" href="https://datatracker.ietf.org/doc/html/rfc3540">3540</a> – Robust Explicit Congestion Notification (ECN) Signaling with Nonces</li> <li><link rel="mw-deduplicated-inline-style" href="mw-data:TemplateStyles:r1238218222"><a href="/wiki/RFC_(identifier)" class="mw-redirect" title="RFC (identifier)">RFC</a> <a rel="nofollow" class="external text" href="https://datatracker.ietf.org/doc/html/rfc4418">4418</a> – UMAC: Message Authentication Code using Universal Hashing</li> <li><a rel="nofollow" class="external text" href="http://docs.oasis-open.org/wss/2004/01/">Web Services Security</a></li></ul>    </div><noscript><img src="https://login.wikimedia.org/wiki/Special:CentralAutoLogin/start?type=1x1" alt="" width="1" height="1" style="border: none; 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