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<span id="openzim-page-title" class="mw-page-title-main"><span class="mw-page-title-main">Ciphertext</span></span>

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</style><div role="note" class="hatnote navigation-not-searchable">This article is about encrypted information. For an overview of cryptographic technology in general, see <a href="Cryptography" title="Cryptography">Cryptography</a>.</div>

<p>In <a href="Cryptography" title="Cryptography">cryptography</a>, <b>ciphertext</b> or <b>cyphertext</b> is the result of <a href="Encryption" title="Encryption">encryption</a> performed on <a href="Plaintext" title="Plaintext">plaintext</a> using an algorithm, called a <a href="Cipher" title="Cipher">cipher</a>.<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> Ciphertext is also known as encrypted or encoded information because it contains a form of the original plaintext that is unreadable by a human or computer without the proper cipher to decrypt it. This process prevents the loss of sensitive information via hacking. <a href="Decryption" class="mw-redirect" title="Decryption">Decryption</a>, the inverse of encryption, is the process of turning ciphertext into readable plaintext. Ciphertext is not to be confused with <a href="Codetext" class="mw-redirect" title="Codetext">codetext</a>, because the latter is a result of a code, not a cipher.

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<div class="mw-heading mw-heading2"><h2 id="Conceptual_underpinnings">Conceptual underpinnings</h2></div>

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<annotation encoding="application/x-tex">{\displaystyle m\!}</annotation>

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</math></span><img src="./e1b2d8ab15f0b9edbafa76777ed0ddcec36855ae.svg" class="mwe-math-fallback-image-inline mw-invert skin-invert" aria-hidden="true" style="vertical-align: -0.338ex; margin-right: -0.338ex; width:1.992ex; height:1.676ex;" alt="{\displaystyle m\!}" loading="lazy"></span> be the plaintext message that Alice wants to secretly transmit to Bob and let <span class="mwe-math-element mwe-math-element-inline"><span class="mwe-math-mathml-inline mwe-math-mathml-a11y" style="display: none;"><math xmlns="http://www.w3.org/1998/Math/MathML" alttext="{\displaystyle E_{k}\!}">

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<annotation encoding="application/x-tex">{\displaystyle E_{k}\!}</annotation>

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</math></span><img src="./305293b3c047f767d26550bf345e294b44ae484b.svg" class="mwe-math-fallback-image-inline mw-invert skin-invert" aria-hidden="true" style="vertical-align: -0.671ex; margin-right: -0.387ex; width:2.804ex; height:2.509ex;" alt="{\displaystyle E_{k}\!}" loading="lazy"></span> be the encryption cipher, where <span class="mwe-math-element mwe-math-element-inline"><span class="mwe-math-mathml-inline mwe-math-mathml-a11y" style="display: none;"><math xmlns="http://www.w3.org/1998/Math/MathML" alttext="{\displaystyle _{k}\!}">

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<annotation encoding="application/x-tex">{\displaystyle _{k}\!}</annotation>

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</math></span><img src="./9b1bb5656be8f4b99a72279e86397bc289964d2a.svg" class="mwe-math-fallback-image-inline mw-invert skin-invert" aria-hidden="true" style="vertical-align: -0.671ex; margin-right: -0.387ex; width:1.089ex; height:1.676ex;" alt="{\displaystyle _{k}\!}" loading="lazy"></span> is a <a href="Secret_key" class="mw-redirect" title="Secret key">cryptographic key</a>. Alice must first transform the plaintext into ciphertext, <span class="mwe-math-element mwe-math-element-inline"><span class="mwe-math-mathml-inline mwe-math-mathml-a11y" style="display: none;"><math xmlns="http://www.w3.org/1998/Math/MathML" alttext="{\displaystyle c\!}">

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<annotation encoding="application/x-tex">{\displaystyle c\!}</annotation>

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</math></span><img src="./62580b3a305faffbdacb0ea283dd1624bf9b37b2.svg" class="mwe-math-fallback-image-inline mw-invert skin-invert" aria-hidden="true" style="vertical-align: -0.338ex; margin-right: -0.38ex; width:1ex; height:1.676ex;" alt="{\displaystyle c\!}" loading="lazy"></span>, in order to securely send the message to Bob, as follows:

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<annotation encoding="application/x-tex">{\displaystyle c=E_{k}(m).\!}</annotation>

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</math></span><img src="./b75cdab762f977641eb1330674abea43784555e3.svg" class="mwe-math-fallback-image-inline mw-invert skin-invert" aria-hidden="true" style="vertical-align: -0.838ex; margin-right: -0.204ex; width:11.222ex; height:2.843ex;" alt="{\displaystyle c=E_{k}(m).\!}" loading="lazy"></span><sup id="cite_ref-Fundamentals_2-0" class="reference"><a href="#cite_note-Fundamentals-2"><span class="cite-bracket">[</span>2<span class="cite-bracket">]</span></a></sup></dd></dl>

<p>In a symmetric-key system, Bob knows Alice's encryption key. Once the message is encrypted, Alice can safely transmit it to Bob (assuming no one else knows the key). In order to read Alice's message, Bob must decrypt the ciphertext using <span class="mwe-math-element mwe-math-element-inline"><span class="mwe-math-mathml-inline mwe-math-mathml-a11y" style="display: none;"><math xmlns="http://www.w3.org/1998/Math/MathML" alttext="{\displaystyle {E_{k}}^{-1}\!}">

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<annotation encoding="application/x-tex">{\displaystyle {E_{k}}^{-1}\!}</annotation>

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</math></span><img src="./d39aab977570c762e28e3036a1197513ba16d68e.svg" class="mwe-math-fallback-image-inline mw-invert skin-invert" aria-hidden="true" style="vertical-align: -0.671ex; margin-right: -0.387ex; width:5.137ex; height:3.009ex;" alt="{\displaystyle {E_{k}}^{-1}\!}" loading="lazy"></span> which is known as the decryption cipher, <span class="mwe-math-element mwe-math-element-inline"><span class="mwe-math-mathml-inline mwe-math-mathml-a11y" style="display: none;"><math xmlns="http://www.w3.org/1998/Math/MathML" alttext="{\displaystyle D_{k}:\!}">

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<annotation encoding="application/x-tex">{\displaystyle D_{k}:\!}</annotation>

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</math></span><img src="./ca9a50c9e782afb2d1cb1fcb43a4425c572019a7.svg" class="mwe-math-fallback-image-inline mw-invert skin-invert" aria-hidden="true" style="vertical-align: -0.671ex; margin-right: -0.204ex; width:4.122ex; height:2.509ex;" alt="{\displaystyle D_{k}:\!}" loading="lazy"></span>

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<annotation encoding="application/x-tex">{\displaystyle D_{k}(c)=D_{k}(E_{k}(m))=m.\!}</annotation>

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</math></span><img src="./1c9473815319aafdf2bed308ef05eba7a9004460.svg" class="mwe-math-fallback-image-inline mw-invert skin-invert" aria-hidden="true" style="vertical-align: -0.838ex; margin-right: -0.204ex; width:26.006ex; height:2.843ex;" alt="{\displaystyle D_{k}(c)=D_{k}(E_{k}(m))=m.\!}" loading="lazy"></span><sup id="cite_ref-Fundamentals_2-1" class="reference"><a href="#cite_note-Fundamentals-2"><span class="cite-bracket">[</span>2<span class="cite-bracket">]</span></a></sup></dd></dl>

<p>Alternatively, in a non-symmetric key system, everyone, not just Alice and Bob, knows the encryption key; but the decryption key cannot be inferred from the encryption key. Only Bob knows the decryption key <span class="mwe-math-element mwe-math-element-inline"><span class="mwe-math-mathml-inline mwe-math-mathml-a11y" style="display: none;"><math xmlns="http://www.w3.org/1998/Math/MathML" alttext="{\displaystyle D_{k},}">

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<annotation encoding="application/x-tex">{\displaystyle D_{k},}</annotation>

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</math></span><img src="./db31f4eb974acd46d954c0100948988aa4c68053.svg" class="mwe-math-fallback-image-inline mw-invert skin-invert" aria-hidden="true" style="vertical-align: -0.671ex; width:3.66ex; height:2.509ex;" alt="{\displaystyle D_{k},}" loading="lazy"></span> and decryption proceeds as

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<annotation encoding="application/x-tex">{\displaystyle D_{k}(c)=m.}</annotation>

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</math></span><img src="./0182ad9da88712d6c8de9cab8b6c9f74412e5da9.svg" class="mwe-math-fallback-image-inline mw-invert skin-invert" aria-hidden="true" style="vertical-align: -0.838ex; width:11.615ex; height:2.843ex;" alt="{\displaystyle D_{k}(c)=m.}" loading="lazy"></span></dd></dl>

<div class="mw-heading mw-heading2"><h2 id="Types_of_ciphers">Types of ciphers</h2></div>

<div role="note" class="hatnote navigation-not-searchable">Main article: <a href="Cipher" title="Cipher">Cipher</a></div>

<p>The <a href="History_of_cryptography" title="History of cryptography">history of cryptography</a> began thousands of years ago. Cryptography uses a variety of different types of encryption. Earlier algorithms were performed by hand and are substantially different from modern <a href="Algorithm" title="Algorithm">algorithms</a>, which are generally executed by a machine.

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<div class="mw-heading mw-heading3"><h3 id="Historical_ciphers">Historical ciphers</h3></div>

<p>Historical pen and paper ciphers used in the past are sometimes known as <a href="Classical_cipher" title="Classical cipher">classical ciphers</a>. They include:

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<ul><li><a href="Substitution_cipher" title="Substitution cipher">Substitution cipher</a>: the units of plaintext are replaced with ciphertext (e.g., <a href="Caesar_cipher" title="Caesar cipher">Caesar cipher</a> and <a href="One-time_pad" title="One-time pad">one-time pad</a>)

<ul><li><a href="Polyalphabetic_substitution" class="mw-redirect" title="Polyalphabetic substitution">Polyalphabetic substitution cipher</a>: a substitution cipher using multiple substitution alphabets (e.g., <a href="Vigen%C3%A8re_cipher" title="Vigenère cipher">Vigenère cipher</a> and <a href="Enigma_machine" title="Enigma machine">Enigma machine</a>)</li>

<li><a href="Polygraphic_substitution" title="Polygraphic substitution">Polygraphic substitution</a> cipher: the unit of substitution is a sequence of two or more letters rather than just one (e.g., <a href="Playfair_cipher" title="Playfair cipher">Playfair cipher</a>)</li></ul></li>

<li><a href="Transposition_cipher" title="Transposition cipher">Transposition cipher</a>: the ciphertext is a <a href="Permutation" title="Permutation">permutation</a> of the plaintext (e.g., <a href="Rail_fence" class="mw-redirect" title="Rail fence">rail fence cipher</a>)</li></ul>

<p>Historical ciphers are not generally used as a standalone encryption technique because they are quite easy to crack. Many of the classical ciphers, with the exception of the one-time pad, can be cracked using <a href="Brute_force_attack" class="mw-redirect" title="Brute force attack">brute force</a>.

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<div class="mw-heading mw-heading3"><h3 id="Modern_ciphers">Modern ciphers</h3></div>

<p>Modern ciphers are more secure than classical ciphers and are designed to withstand a wide range of attacks. An attacker should not be able to find the key used in a modern cipher, even if they know any specifics about the plaintext and its corresponding ciphertext. Modern encryption methods can be divided into the following categories:

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<ul><li><a href="Private-key_cryptography" class="mw-redirect" title="Private-key cryptography">Private-key cryptography</a> (<a href="Symmetric_key_algorithm" class="mw-redirect" title="Symmetric key algorithm">symmetric key algorithm</a>): one shared key is used for encryption and decryption</li>

<li><a href="Public-key_cryptography" title="Public-key cryptography">Public-key cryptography</a> (<a href="Asymmetric_key_algorithm" class="mw-redirect" title="Asymmetric key algorithm">asymmetric key algorithm</a>): two different keys are used for encryption and decryption</li></ul>

<p>In a symmetric key algorithm (e.g., <a href="Data_Encryption_Standard" title="Data Encryption Standard">DES</a>, <a href="Advanced_Encryption_Standard" title="Advanced Encryption Standard">AES</a>), the sender and receiver have a shared key established in advance: the sender uses the shared key to perform encryption; the receiver uses the shared key to perform decryption. Symmetric key algorithms can either be <a href="Block_cipher" title="Block cipher">block ciphers</a> or <a href="Stream_cipher" title="Stream cipher">stream ciphers</a>. Block ciphers operate on fixed-length groups of bits, called blocks, with an unvarying transformation. Stream ciphers encrypt plaintext digits one at a time on a continuous stream of data, with the transformation of successive digits varying during the encryption process.

</p><p>In an asymmetric key algorithm (e.g., <a href="RSA_(algorithm)" class="mw-redirect" title="RSA (algorithm)">RSA</a>), there are two different keys: a <i>public key</i> and a <i>private key.</i> The <i>public key</i> is published, thereby allowing any sender to perform encryption. The <i>private key</i> is kept secret by the receiver, thereby allowing only the receiver to correctly perform decryption.

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<div class="mw-heading mw-heading2"><h2 id="Cryptanalysis">Cryptanalysis</h2></div>

<div role="note" class="hatnote navigation-not-searchable">Main article: <a href="Cryptanalysis" title="Cryptanalysis">Cryptanalysis</a></div>

<p>Cryptanalysis (also referred to as codebreaking or <a href="Password_cracking" title="Password cracking">cracking the code</a>) is the study of applying various methodologies to obtain the meaning of encrypted information, without having access to the cipher required to correctly decrypt the information. This typically involves gaining an understanding of the system design and determining the cipher.

</p><p>Cryptanalysts can follow one or more <a href="Attack_model" title="Attack model">attack models</a> to crack a cipher, depending upon what information is available and the type of cipher being analyzed. Ciphertext is generally the most easily obtained part of a <a href="Cryptosystem" title="Cryptosystem">cryptosystem</a> and therefore is an important part of cryptanalysis.

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<div class="mw-heading mw-heading3"><h3 id="Attack_models">Attack models</h3></div>

<ul><li><a href="Ciphertext-only_attack" title="Ciphertext-only attack">Ciphertext-only</a>: the cryptanalyst has access only to a collection of ciphertexts or code texts. This is the weakest attack model because the cryptanalyst has limited information. Modern ciphers rarely fail under this attack.<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></li>

<li><a href="Known-plaintext_attack" title="Known-plaintext attack">Known-plaintext</a>: the attacker has a set of ciphertexts to which they know the corresponding plaintext</li>

<li><a href="Chosen-plaintext_attack" title="Chosen-plaintext attack">Chosen-plaintext attack</a>: the attacker can obtain the ciphertexts corresponding to an arbitrary set of plaintexts of their own choosing

<ul><li>Batch chosen-plaintext attack: where the cryptanalyst chooses all plaintexts before any of them are encrypted. This is often the meaning of an unqualified use of "chosen-plaintext attack".</li>

<li>Adaptive chosen-plaintext attack: where the cryptanalyst makes a series of interactive queries, choosing subsequent plaintexts based on the information from the previous encryptions.</li></ul></li>

<li><a href="Chosen-ciphertext_attack" title="Chosen-ciphertext attack">Chosen-ciphertext attack</a>: the attacker can obtain the plaintexts corresponding to an arbitrary set of ciphertexts of their own choosing

<ul><li><a href="Adaptive_chosen-ciphertext_attack" title="Adaptive chosen-ciphertext attack">Adaptive chosen-ciphertext attack</a></li>

<li><a href="Indifferent_chosen-ciphertext_attack" class="mw-redirect" title="Indifferent chosen-ciphertext attack">Indifferent chosen-ciphertext attack</a></li></ul></li>

<li><a href="Related-key_attack" title="Related-key attack">Related-key attack</a>: similar to a chosen-plaintext attack, except the attacker can obtain ciphertexts encrypted under two different keys. The keys are unknown, but the relationship between them is known (e.g., two keys that differ in the one bit).</li></ul>

<div class="mw-heading mw-heading2"><h2 id="Famous_ciphertexts">Famous ciphertexts</h2></div>

<div role="note" class="hatnote navigation-not-searchable">Main article: <a href="List_of_ciphertexts" title="List of ciphertexts">List of ciphertexts</a></div>

<ul><li>The <a href="Babington_Plot" title="Babington Plot">Babington Plot</a> ciphers</li>

<li>The <a href="Shugborough_inscription" title="Shugborough inscription">Shugborough inscription</a></li>

<li>The <a href="Zimmermann_Telegram" class="mw-redirect" title="Zimmermann Telegram">Zimmermann Telegram</a></li>

<li><a href="The_Magic_Words_are_Squeamish_Ossifrage" title="The Magic Words are Squeamish Ossifrage">The Magic Words are Squeamish Ossifrage</a></li>

<li>The <a href="Cryptogram" title="Cryptogram">cryptogram</a> in "<a href="The_Gold-Bug" title="The Gold-Bug">The Gold-Bug</a>"</li>

<li><a href="Beale_ciphers" title="Beale ciphers">Beale ciphers</a></li>

<li><a href="Kryptos" title="Kryptos">Kryptos</a></li>

<li><a href="Zodiac_Killer" title="Zodiac Killer">Zodiac Killer</a> ciphers</li></ul>

<ul><li><a href="Bibliography_of_cryptography" title="Bibliography of cryptography">Bibliography of cryptography</a></li>

<li><a href="Cryptographic_hash_function" title="Cryptographic hash function">Cryptographic hash function</a></li>

<li><a href="Frequency_analysis" title="Frequency analysis">Frequency analysis</a></li>

<li><a href="RED/BLACK_concept" class="mw-redirect" title="RED/BLACK concept">RED/BLACK concept</a></li></ul>

<div class="mw-heading mw-heading2"><h2 id="References">References</h2></div>

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</style><cite id="CITEREFBerti,_Hansche,_Hare2003" class="citation book cs1">Berti, Hansche, Hare (2003). <i>Official (ISC)² Guide to the <a href="CISSP" class="mw-redirect" title="CISSP">CISSP</a> Exam</i>. Auerbach Publications. pp. <a rel="nofollow" class="external text" href="https://archive.org/details/officialiscguide0000hans/page/379">379</a>. <a href="ISBN_(identifier)" class="mw-redirect" title="ISBN (identifier)">ISBN</a> <bdi>0-8493-1707-X</bdi>.</cite><span class="cs1-maint citation-comment"><code class="cs1-code">{{cite book}}</code>: CS1 maint: multiple names: authors list (link)</span></span>

</li>

<li id="cite_note-Fundamentals-2"><span class="mw-cite-backlink">^ <a href="#cite_ref-Fundamentals_2-0"><sup><i><b>a</b></i></sup></a> <a href="#cite_ref-Fundamentals_2-1"><sup><i><b>b</b></i></sup></a></span> <span class="reference-text"><cite id="CITEREFvan_Tilborg2000" class="citation book cs1">van Tilborg, Henk C.A. (2000). <i>Fundamentals of Cryptology</i>. Kluwer Academic Publishers. p. 3. <a href="ISBN_(identifier)" class="mw-redirect" title="ISBN (identifier)">ISBN</a> <bdi>0-7923-8675-2</bdi>.</cite></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"><cite id="CITEREFSchneier2000" class="citation book cs1">Schneier, Bruce (28 August 2000). <a rel="nofollow" class="external text" href="https://archive.org/details/secretsliesdigit00schn/page/90"><i>Secrets & Lies</i></a>. Wiley Computer Publishing Inc. pp. <a rel="nofollow" class="external text" href="https://archive.org/details/secretsliesdigit00schn/page/90">90–91</a>. <a href="ISBN_(identifier)" class="mw-redirect" title="ISBN (identifier)">ISBN</a> <bdi>0-471-25311-1</bdi>.</cite></span>

</li>

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<div class="mw-heading mw-heading2"><h2 id="Further_reading">Further reading</h2></div>

<ul><li><span class="noviewer" typeof="mw:File"></span> The dictionary definition of <a href="https://en.wiktionary.org/wiki/Special:Search/ciphertext" class="extiw external" title="wiktionary:Special:Search/ciphertext"><i>ciphertext</i></a> at Wiktionary</li>

<li><span class="noviewer" typeof="mw:File"></span> Media related to <a href="https://commons.wikimedia.org/wiki/Category:Ciphertexts" class="extiw external" title="commons:Category:Ciphertexts">Ciphertexts</a> at Wikimedia Commons</li>

<li>Helen Fouché Gaines, “Cryptanalysis”, 1939, Dover. <a href="ISBN_(identifier)" class="mw-redirect" title="ISBN (identifier)">ISBN</a> <bdi>0-486-20097-3</bdi></li>

<li><a href="David_Kahn_(writer)" title="David Kahn (writer)">David Kahn</a>, <i>The Codebreakers - The Story of Secret Writing</i> (<a href="ISBN_(identifier)" class="mw-redirect" title="ISBN (identifier)">ISBN</a> <bdi>0-684-83130-9</bdi>) (1967)</li>

<li><a href="Abraham_Sinkov" title="Abraham Sinkov">Abraham Sinkov</a>, <i>Elementary Cryptanalysis: A Mathematical Approach</i>, Mathematical Association of America, 1968. <a href="ISBN_(identifier)" class="mw-redirect" title="ISBN (identifier)">ISBN</a> <bdi>0-88385-622-0</bdi></li></ul>

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<ul><li><a href="History_of_cryptography" title="History of cryptography">History of cryptography</a></li>

<li><a href="Outline_of_cryptography" title="Outline of cryptography">Outline of cryptography</a></li>

<li><a href="Classical_cipher" title="Classical cipher">Classical cipher</a></li>

<li><a href="Cryptographic_protocol" title="Cryptographic protocol">Cryptographic protocol</a>

<ul><li><a href="Authentication_protocol" title="Authentication protocol">Authentication protocol</a></li></ul></li>

<li><a href="Cryptographic_primitive" title="Cryptographic primitive">Cryptographic primitive</a></li>

<li><a href="Cryptanalysis" title="Cryptanalysis">Cryptanalysis</a></li>

<li><a href="Cryptocurrency" title="Cryptocurrency">Cryptocurrency</a></li>

<li><a href="Cryptosystem" title="Cryptosystem">Cryptosystem</a></li>

<li><a href="Cryptographic_nonce" title="Cryptographic nonce">Cryptographic nonce</a></li>

<li><a href="Cryptovirology" title="Cryptovirology">Cryptovirology</a></li>

<li><a href="Hash_function" title="Hash function">Hash function</a>

<ul><li><a href="Cryptographic_hash_function" title="Cryptographic hash function">Cryptographic hash function</a></li>

<li><a href="Key_derivation_function" title="Key derivation function">Key derivation function</a></li>

<li><a href="Secure_Hash_Algorithms" title="Secure Hash Algorithms">Secure Hash Algorithms</a></li></ul></li>

<li><a href="Digital_signature" title="Digital signature">Digital signature</a></li>

<li><a href="Kleptography" title="Kleptography">Kleptography</a></li>

<li><a href="Key_(cryptography)" title="Key (cryptography)">Key (cryptography)</a></li>

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<li><a href="Key_generator" title="Key generator">Key generator</a></li>

<li><a href="Key_schedule" title="Key schedule">Key schedule</a></li>

<li><a href="Key_stretching" title="Key stretching">Key stretching</a></li>

<li><a href="Keygen" title="Keygen">Keygen</a></li>

<li>Machines</li>

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<li><a href="Random_number_generation" title="Random number generation">Random number generation</a>

<ul><li><a href="Cryptographically_secure_pseudorandom_number_generator" title="Cryptographically secure pseudorandom number generator">Cryptographically secure pseudorandom number generator</a> (CSPRNG)</li></ul></li>

<li><a href="Pseudorandom_noise" title="Pseudorandom noise">Pseudorandom noise</a> (PRN)</li>

<li><a href="Secure_channel" title="Secure channel">Secure channel</a></li>

<li><a href="Insecure_channel" class="mw-redirect" title="Insecure channel">Insecure channel</a></li>

<li><a href="Subliminal_channel" title="Subliminal channel">Subliminal channel</a></li>

<li><a href="Encryption" title="Encryption">Encryption</a></li>

<li><a href="Decryption" class="mw-redirect" title="Decryption">Decryption</a></li>

<li><a href="End-to-end_encryption" title="End-to-end encryption">End-to-end encryption</a></li>

<li><a href="Harvest_now%2C_decrypt_later" title="Harvest now, decrypt later">Harvest now, decrypt later</a></li>

<li><a href="Information-theoretic_security" title="Information-theoretic security">Information-theoretic security</a></li>

<li><a href="Plaintext" title="Plaintext">Plaintext</a></li>

<li><a href="Codetext" class="mw-redirect" title="Codetext">Codetext</a></li>

<li><a href="Shared_secret" title="Shared secret">Shared secret</a></li>

<li><a href="Trapdoor_function" title="Trapdoor function">Trapdoor function</a></li>

<li><a href="Trusted_timestamping" title="Trusted timestamping">Trusted timestamping</a></li>

<li><a href="Key-based_routing" title="Key-based routing">Key-based routing</a></li>

<li><a href="Onion_routing" title="Onion routing">Onion routing</a></li>

<li><a href="Garlic_routing" title="Garlic routing">Garlic routing</a></li>

<li><a href="Kademlia" title="Kademlia">Kademlia</a></li>

<li><a href="Mix_network" title="Mix network">Mix network</a></li></ul>

</div></td></tr><tr><th scope="row" class="navbox-group" style="width:1%">Mathematics</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="Cryptographic_hash_function" title="Cryptographic hash function">Cryptographic hash function</a></li>

<li><a href="Block_cipher" title="Block cipher">Block cipher</a></li>

<li><a href="Stream_cipher" title="Stream cipher">Stream cipher</a></li>

<li><a href="Symmetric-key_algorithm" title="Symmetric-key algorithm">Symmetric-key algorithm</a></li>

<li><a href="Authenticated_encryption" title="Authenticated encryption">Authenticated encryption</a></li>

<li><a href="Public-key_cryptography" title="Public-key cryptography">Public-key cryptography</a></li>

<li><a href="Quantum_key_distribution" title="Quantum key distribution">Quantum key distribution</a></li>

<li><a href="Quantum_cryptography" title="Quantum cryptography">Quantum cryptography</a></li>

<li><a href="Post-quantum_cryptography" title="Post-quantum cryptography">Post-quantum cryptography</a></li>

<li><a href="Message_authentication_code" title="Message authentication code">Message authentication code</a></li>

<li><a href="Cryptographically_secure_pseudorandom_number_generator" title="Cryptographically secure pseudorandom number generator">Random numbers</a></li>

<li><a href="Steganography" title="Steganography">Steganography</a></li></ul>

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