Advanced Encryption Standard: Difference between revisions

Revision as of 14:43, 26 November 2024

Latest revision as of 13:04, 21 August 2025

(40 intermediate revisions by 26 users not shown)

Line 16:

| cryptanalysis = Attacks have been published that are computationally faster than a full [[brute-force attack]], though none as of 2023 are computationally feasible.<ref name="aesbc">{{cite web |url=http://research.microsoft.com/en-us/projects/cryptanalysis/aesbc.pdf |archive-url=https://web.archive.org/web/20160306104007/http://research.microsoft.com/en-us/projects/cryptanalysis/aesbc.pdf |archive-date=March 6, 2016 |title=Biclique Cryptanalysis of the Full AES |access-date=May 1, 2019 |url-status=dead |df=mdy-all}}</ref>

For AES-128, the key can be recovered with a [[computational complexity]] of 2^126.1 using the [[biclique attack]]. For biclique attacks on AES-192 and AES-256, the computational complexities of 2^189.7 and 2^254.4 respectively apply. [[Related-key attack]]s can break AES-256192 and AES-192256 with complexities 2^99.5 and 2¹⁷⁶ in both time and data, respectively.<ref name = relkey>Alex Biryukov and Dmitry Khovratovich, ''Related-key Cryptanalysis of the Full AES-192 and AES-256'', {{cite web |url=https://eprint.iacr.org/2009/317 |title=Related-key Cryptanalysis of the Full AES-192 and AES-256 |access-date=2010-02-16 |url-status=live |archive-url=https://web.archive.org/web/20090928014006/http://eprint.iacr.org/2009/317 |archive-date=2009-09-28 |at=Table 1}}</ref>

Another attack was blogged<ref name="Bruce Schneier">{{cite web |url=http://www.schneier.com/blog/archives/2009/07/another_new_aes.html |title=Another New AES Attack |author=Bruce Schneier |date=2009-07-30 |work=Schneier on Security, A blog covering security and security technology |access-date=2010-03-11 |url-status=live |archive-url=https://web.archive.org/web/20091005183132/http://www.schneier.com/blog/archives/2009/07/another_new_aes.html |archive-date=2009-10-05}}</ref> and released as a [[preprint]]<ref>{{cite web |url=https://eprint.iacr.org/2009/374 |title=Key Recovery Attacks of Practical Complexity on AES Variants With Up To 10 Rounds |author=Alex Biryukov |author2=Orr Dunkelman |author3=Nathan Keller |author4=Dmitry Khovratovich |author5=Adi Shamir |date=2009-08-19 |access-date=2010-03-11 |archive-url=https://web.archive.org/web/20100128050656/http://eprint.iacr.org/2009/374 |archive-date=28 January 2010 |url-status=live}}</ref> in 2009. This attack is against AES-256 that uses only two related keys and 2³⁹ time to recover the complete 256-bit key of a 9-round version, or 2⁴⁵ time for a 10-round version with a stronger type of related subkey attack, or 2⁷⁰ time for an 11-round version.

Line 24:

The '''Advanced Encryption Standard''' ('''AES'''), also known by its original name '''Rijndael''' ({{IPA|nl|ˈrɛindaːl}}),<ref name="Rijndael-ammended.pdf" /> is a specification for the [[encryption]] of electronic data established by the U.S. [[National Institute of Standards and Technology]] (NIST) in 2001.<ref name="fips-197">{{cite web |url=https://nvlpubs.nist.gov/nistpubs/FIPS/NIST.FIPS.197-upd1.pdf |title=Announcing the ADVANCED ENCRYPTION STANDARD (AES) |publisher=United States National Institute of Standards and Technology (NIST) |work=Federal Information Processing Standards Publication 197 |date=November 26, 2001 |access-date=August 26, 2024 |url-status=live |archive-url=https://web.archive.org/web/20240823165748/https://nvlpubs.nist.gov/nistpubs/FIPS/NIST.FIPS.197-upd1.pdf |archive-date=August 23, 2024}}</ref>

AES is a variant of the Rijndael [[block cipher]]<ref name="Rijndael-ammended.pdf">{{cite web |url=http://csrc.nist.gov/archive/aes/rijndael/Rijndael-ammended.pdf#page=1 |title=AES Proposal: Rijndael |last1=Daemen |first1=Joan |last2=Rijmen |first2=Vincent |date=March 9, 2003 |publisher=National Institute of Standards and Technology |page=1 |access-date=21 February 2013 |url-status=live |archive-url=https://web.archive.org/web/20130305143117/http://csrc.nist.gov/archive/aes/rijndael/Rijndael-ammended.pdf#page=1 |archive-date=5 March 2013}}</ref> developed by two [[Belgium|Belgian]] cryptographers, [[Joan Daemen]] and [[Vincent Rijmen]], who submitted a proposal<ref name="Rijndaelv2">{{cite web |url=http://csrc.nist.gov/CryptoToolkit/aes/rijndael/Rijndael.pdf |url-status=dead |archive-url=https://web.archive.org/web/20070203204845/https://csrc.nist.gov/CryptoToolkit/aes/rijndael/Rijndael.pdf |archive-date=February 3, 2007 |title=AES Proposal: Rijndael |author=Joan Daemen and Vincent Rijmen |date=September 3, 1999}}</ref> to NIST during the [[Advanced Encryption Standard process|AES selection process]].<ref>{{Cite news |title=U.S. Selects a New Encryption Technique |authorfirst=John |last=Schwartz |newspaper=[[The New York Times]] |date=October 3, 2000 |url=https://www.nytimes.com/2000/10/03/business/technology-us-selects-a-new-encryption-technique.html |url-status=live |archive-url=https://web.archive.org/web/20170328215407/http://www.nytimes.com/2000/10/03/business/technology-us-selects-a-new-encryption-technique.html |archive-date=March 28, 2017}}</ref> Rijndael is a family of ciphers with different [[key size|key]] and [[Block size (cryptography)|block sizessize]]s. For AES, NIST selected three members of the Rijndael family, each with a block size of 128 bits, but three different key lengths: 128, 192 and 256 bits.

AES has been adopted by the [[Federal government of the United States|U.S. government]]. It supersedes the [[Data Encryption Standard]] (DES),<ref>{{cite news |url=http://www.findarticles.com/p/articles/mi_m0IKZ/is_3_107?pnum=2&opg=90984479 |title=NIST reports measurable success of Advanced Encryption Standard |work=Journal of Research of the National Institute of Standards and Technology |first=Harold B. |last=Westlund |date=2002 |url-status=dead |archive-url=https://web.archive.org/web/20071103105501/http://findarticles.com/p/articles/mi_m0IKZ/is_3_107?pnum=2&opg=90984479 |archive-date=2007-11-03}}</ref> which was published in 1977. The algorithm described by AES is a [[symmetric-key algorithm]], meaning the same key is used for both encrypting and decrypting the data.

Line 32:

AES is included in the [[International Organization for Standardization|ISO]]/[[International Electrotechnical Commission|IEC]] [[List of International Organization for Standardization standards, 18000-19999|18033-3]] standard. AES became effective as a U.S. federal government standard on May 26, 2002, after approval by U.S. [[United States Secretary of Commerce|Secretary of Commerce]] [[Donald Evans]]. AES is available in many different encryption packages, and is the first (and only) publicly accessible [[cipher]] approved by the U.S. [[National Security Agency]] (NSA) for [[Classified information|top secret]] information when used in an NSA approved cryptographic module.<ref group="note">See [[Advanced Encryption Standard#Security|Security of AES]] below.</ref>

== Definitive standards ==

GEORGE SIMION

The Advanced Encryption Standard (AES) is defined in each of:

* FIPS PUB 197: Advanced Encryption Standard (AES)<ref name="fips-197" />

* ISO/IEC 18033-3: Block ciphers<ref name="ISO_IEC_AES">{{cite web |url=http://www.iso.org/iso/home/store/catalogue_ics/catalogue_detail_ics.htm?csnumber=54531 |title=ISO/IEC 18033-3: Information technology – Security techniques – Encryption algorithms – Part 3: Block ciphers |url-status=live |archive-url=https://web.archive.org/web/20131203003348/http://www.iso.org/iso/home/store/catalogue_ics/catalogue_detail_ics.htm?csnumber=54531 |archive-date=2013-12-03}}</ref>

== Description of the ciphers ==

Line 120 ⟶ 125:

AES has 10 rounds for 128-bit keys, 12 rounds for 192-bit keys, and 14 rounds for 256-bit keys.

By 2006, the best known attacks were on 7 rounds for 128-bit keys, 8 rounds for 192-bit keys, and 9 rounds for 256-bit keys.<ref name="improved">[[John Kelsey (cryptanalyst)|John Kelsey]], [[Stefan Lucks]], [[Bruce Schneier]], [[Mike Stay]], [[David A. Wagner|David Wagner]], and [[Doug Whiting]], ''Improved Cryptanalysis of Rijndael'', [[Fast Software Encryption]], 2000 pp213–230 {{cite web |title=Academic: Improved Cryptanalysis of Rijndael - Schneier on Security |url=http://www.schneier.com/paper-rijndael.html |url-status=live |archive-url=https://web.archive.org/web/20070223215007/http://www.schneier.com/paper-rijndael.html |archive-date=2007-02-23 |access-date=2007-03-06}}</ref>

=== Known attacks ===

Line 132 ⟶ 135:

During the AES selection process, developers of competing algorithms wrote of Rijndael's algorithm "we are concerned about [its] use ... in security-critical applications."<ref name="rijndael-algebraic">

{{cite conference |author=Niels Ferguson |author-link=Niels Ferguson |author2=Richard Schroeppel |author2-link=Richard Schroeppel |author3=Doug Whiting |title=A simple algebraic representation of Rijndael |book-title=Proceedings of Selected Areas in Cryptography, 2001, Lecture Notes in Computer Science |pages=103–111 |publisher=[[Springer-Verlag]] |date=2001 |url=http://www.macfergus.com/pub/rdalgeq.html |format=PDF/[[PostScript]] |access-date=2006-10-06 |archive-url=https://web.archive.org/web/20061104080748/http://www.macfergus.com/pub/rdalgeq.html |archive-date=4 November 2006 |citeseerx=10.1.1.28.4921}}</ref> In October 2000, however, at the end of the AES selection process, [[Bruce Schneier]], a developer of the competing algorithm [[Twofish]], wrote that while he thought successful academic attacks on Rijndael would be developed someday, he "did not believe that anyone will ever discover an attack that will allow someone to read Rijndael traffic."<ref>Bruce Schneier, [http://www.schneier.com/crypto-gram-0010.html AES Announced] {{webarchive|url=https://web.archive.org/web/20090201005720/http://www.schneier.com/crypto-gram-0010.html |date=2009-02-01 }}, October 15, 2000</ref>

By 2006, the best known attacks were on 7 rounds for 128-bit keys, 8 rounds for 192-bit keys, and 9 rounds for 256-bit keys.<ref name="improved">[[John Kelsey (cryptanalyst)|John Kelsey]], [[Stefan Lucks]], [[Bruce Schneier]], [[Mike Stay]], [[David A. Wagner|David Wagner]], and [[Doug Whiting]], ''Improved Cryptanalysis of Rijndael'', [[Fast Software Encryption]], 2000 pp213–230 {{cite web |title=Academic: Improved Cryptanalysis of Rijndael - Schneier on Security |url=http://www.schneier.com/paper-rijndael.html |url-status=live |archive-url=https://web.archive.org/web/20070223215007/http://www.schneier.com/paper-rijndael.html |archive-date=2007-02-23 |access-date=2007-03-06}}</ref>

Until May 2009, the only successful published attacks against the full AES were [[side-channel attack]]s on some specific implementations. In 2009, a new [[related-key attack]] was discovered that exploits the simplicity of AES's key schedule and has a complexity of 2¹¹⁹. In December 2009 it was improved to 2^99.5.<ref name=relkey /> This is a follow-up to an attack discovered earlier in 2009 by [[Alex Biryukov]], [[Dmitry Khovratovich]], and Ivica Nikolić, with a complexity of 2⁹⁶ for one out of every 2³⁵ keys.<ref>{{cite book |volume=5677 |chapter=Distinguisher and Related-Key Attack on the Full AES-256 |last1=Nikolić |first1=Ivica |title=Advances in Cryptology - CRYPTO 2009 |date=2009 |publisher=Springer Berlin / Heidelberg |isbn=978-3-642-03355-1 |pages=231–249 |doi=10.1007/978-3-642-03356-8_14 |series=Lecture Notes in Computer Science}}</ref> However, related-key attacks are not of concern in any properly designed cryptographic protocol, as a properly designed protocol (i.e., implementational software) will take care not to allow related keys, essentially by [[Related-key attack#Preventing related-key attacks|constraining]] an attacker's means of selecting keys for relatedness.

Line 141 ⟶ 146:

The practicality of these attacks with stronger related keys has been criticized,<ref>{{Cite book |title=On Some Symmetric Lightweight Cryptographic Designs |last=Agren |first=Martin |publisher=Dissertation, Lund University |year=2012 |pages=38–39}}</ref> for instance, by the paper on chosen-key-relations-in-the-middle attacks on AES-128 authored by Vincent Rijmen in 2010.<ref>{{cite journal |url=http://eprint.iacr.org/2010/337.pdf |title=Practical-Titled Attack on AES-128 Using Chosen-Text Relations |author=Vincent Rijmen |date=2010 |journal=IACR Cryptology ePrint Archive |url-status=live |archive-url=https://web.archive.org/web/20100702184311/http://eprint.iacr.org/2010/337.pdf |archive-date=2010-07-02}}</ref>

In November 2009, the first [[known-key distinguishing attack]] against a reduced 8-round version of AES-128 was released as a preprint.<ref>{{cite webjournal |url=http://eprint.iacr.org/2009/531 |title=Super-Sbox Cryptanalysis: Improved Attacks for AES-like permutations |author=Henri Gilbert |author2=Thomas Peyrin |date=2009-11-09 |journal=IACR Cryptology ePrint Archive |access-date=2010-03-11 |url-status=live |archive-url=https://web.archive.org/web/20100604095754/http://eprint.iacr.org/2009/531 |archive-date=2010-06-04}}</ref>

This known-key distinguishing attack is an improvement of the rebound, or the start-from-the-middle attack, against AES-like permutations, which view two consecutive rounds of permutation as the application of a so-called Super-S-box. It works on the 8-round version of AES-128, with a time complexity of 2⁴⁸, and a memory complexity of 2³². 128-bit AES uses 10 rounds, so this attack is not effective against full AES-128.

The first [[key-recovery attack]]s on full AES were by Andrey Bogdanov, Dmitry Khovratovich, and Christian Rechberger, and were published in 2011.<ref>{{Cite book |chapter=Biclique Cryptanalysis of the Full AES |title=Advances in Cryptology – ASIACRYPT 2011 |lastlast1=Bogdanov |firstfirst1=Andrey |volume=7073 |pages=344-371344–371 |last2=Khovratovich |first2=Dmitry |last3=Rechberger |first3=Christian |doi=10.1007/978-3-642-25385-0_19 |series=Lecture Notes in Computer Science |date=2011 |editor-first1=Dong Hoon |editor-last1=Lee |editor-first2=Xiaoyun |editor-last2=Wang |isbn=978-3-642-25385-0}}</ref> The attack is a [[biclique attack]] and is faster than brute force by a factor of about four. It requires 2^126.2 operations to recover an AES-128 key. For AES-192 and AES-256, 2^190.2 and 2^254.6 operations are needed, respectively. This result has been further improved to 2^126.0 for AES-128, 2^189.9 for AES-192, and 2^254.3 for AES-256 by Biaoshuai Tao and Hongjun Wu in a 2015 paper,<ref name=":0">{{cite book |firstfirst1=Biaoshuai |lastlast1=Tao |title=Information Security and Privacy |volume=9144 |pages=39–56 |first2=Hongjun |last2=Wu |chapter=Improving the Biclique Cryptanalysis of AES |date=2015 |doi=10.1007/978-3-319-19962-7_3 |series=Lecture Notes in Computer Science |isbn=978-3-319-19962-7 |editor-first1=Ernest |editor-last1=Foo |editor-first2=Douglas |editor-last2=Stebila}}</ref> which are the current best results in key recovery attack against AES.

This is a very small gain, as a 126-bit key (instead of 128 bits) would still take billions of years to brute force on current and foreseeable hardware. Also, the authors calculate the best attack using their technique on AES with a 128-bit key requires storing 2⁸⁸ bits of data. That works out to about 38 trillion terabytes of data, which was more than all the data stored on all the computers on the planet in 2016.<ref>{{cite web |author=Jeffrey Goldberg |title=AES Encryption isn't Cracked |url=https://blog.agilebits.com/2011/08/18/aes-encryption-isnt-cracked/ |access-date=30 December 2014 |url-status=dead |archive-url=https://web.archive.org/web/20150108165723/https://blog.agilebits.com/2011/08/18/aes-encryption-isnt-cracked/ |archive-date=8 January 2015 |date=2011-08-18}}</ref> A paper in 2015 later improved the space complexity to 2⁵⁶ bits,<ref name=":0"/> which is 9007 terabytes (while still keeping a time complexity of approximately 2^126.2).

According to the [[Edward Snowden#Surveillance disclosures|Snowden documents]], the NSA is doing research on whether a cryptographic attack based on [[Kendall tau rank correlation coefficient|tau statistic]] may help to break AES.<ref>{{cite news |url=http://www.spiegel.de/international/germany/inside-the-nsa-s-war-on-internet-security-a-1010361.html |title=Prying Eyes: Inside the NSA's War on Internet Security |author___location=((SPIEGEL ONLINE, Hamburg, Germany)) |date=28 December 2014 |newspaperwork=SPIEGEL[[Der Spiegel (website)|Spiegel ONLINEOnline]] |access-date=4 September 2015 |url-status=live |archive-url=https://web.archive.org/web/20150124202809/http://www.spiegel.de/international/germany/inside-the-nsa-s-war-on-internet-security-a-1010361.html |archive-date=24 January 2015}}</ref>

At present, there is no known practical attack that would allow someone without knowledge of the key to read data encrypted by AES when correctly implemented.{{cn|date=September 2024}}

Line 156 ⟶ 161:

[[Side-channel attack]]s do not attack the cipher as a [[black box]], and thus are not related to cipher security as defined in the classical context, but are important in practice. They attack implementations of the cipher on hardware or software systems that inadvertently leak data. There are several such known attacks on various implementations of AES.

In April 2005, [[Daniel J. Bernstein|D.&nbsp;J. Bernstein]] announced a cache-timing attack that he used to break a custom server that used [[OpenSSL]]'s AES encryption.<ref name="bernstein_timing">{{cite web |url=http://cr.yp.to/papers.html#cachetiming |title=Index of formal scientific papers |publisher=Cr.yp.to |access-date=2008-11-02 |url-status=live |archive-url=https://web.archive.org/web/20080917042758/http://cr.yp.to/papers.html#cachetiming |archive-date=2008-09-17}}</ref> The attack required over 200 million chosen plaintexts.<ref>{{cite web |url=http://www.schneier.com/blog/archives/2005/05/aes_timing_atta_1.html |title=AES Timing Attack |author=Bruce Schneier |date=17 May 2005 |access-date=2007-03-17 |archive-url=https://web.archive.org/web/20070212015727/http://www.schneier.com/blog/archives/2005/05/aes_timing_atta_1.html |archive-date=12 February 2007 |url-status=live}}</ref> The custom server was designed to give out as much timing information as possible (the server reports back the number of machine cycles taken by the encryption operation). However, as Bernstein pointed out, "reducing the precision of the server's timestamps, or eliminating them from the server's responses, does not stop the attack: the client simply uses round-trip timings based on its local clock, and compensates for the increased noise by averaging over a larger number of samples."<ref name="bernstein_timing" />

In October 2005, Dag Arne Osvik, [[Adi Shamir]] and [[Eran Tromer]] presented a paper demonstrating several cache-timing attacks against the implementations in AES found in OpenSSL and Linux's <code>dm-crypt</code> partition encryption function.<ref>{{cite journalbook |chapter-url=http://www.wisdom.weizmann.ac.il/~tromer/papers/cache.pdf |worktitle=The Cryptographer's Track at RSA Conference 2006 |titlechapter=Cache Attacks and Countermeasures: the Case of AES |date=2005-11-20 |author=Dag Arne Osvik |author2=Adi Shamir |author3=Eran Tromer |series=Lecture Notes in Computer Science |volume=3860 |pages=1–20 |access-date=2008-11-02 |doi=10.1007/11605805_1 |isbn=978-3-540-31033-4 |url-status=live |archive-url=https://web.archive.org/web/20060619221046/http://www.wisdom.weizmann.ac.il/%7Etromer/papers/cache.pdf |archive-date=2006-06-19}}</ref> One attack was able to obtain an entire AES key after only 800&nbsp;operations triggering encryptions, in a total of 65&nbsp;milliseconds. This attack requires the attacker to be able to run programs on the same system or platform that is performing AES.

In December 2009 an attack on some hardware implementations was published that used [[differential fault analysis]] and allows recovery of a key with a complexity of 2³².<ref>{{cite journal |url=http://eprint.iacr.org/2009/581.pdf |title=A Diagonal Fault Attack on the Advanced Encryption Standard |author=Dhiman Saha |author2=Debdeep Mukhopadhyay |author3=Dipanwita RoyChowdhury|author3-link=Dipanwita Roy Chowdhury |access-date=2009-12-08 |journal=IACR Cryptology ePrint Archive |archive-url=https://web.archive.org/web/20091222070135/http://eprint.iacr.org/2009/581.pdf |archive-date=22 December 2009 |url-status=live}}</ref>

Line 164 ⟶ 169:

In November 2010 Endre Bangerter, David Gullasch and Stephan Krenn published a paper which described a practical approach to a "near real time" recovery of secret keys from AES-128 without the need for either cipher text or plaintext. The approach also works on AES-128 implementations that use compression tables, such as OpenSSL.<ref>{{cite journal |url=http://eprint.iacr.org/2010/594.pdf |title=Cache Games – Bringing Access-Based Cache Attacks on AES to Practice |author=Endre Bangerter |author2=David Gullasch |author3=Stephan Krenn |name-list-style=amp |date=2010 |journal=IACR Cryptology ePrint Archive |url-status=live |archive-url=https://web.archive.org/web/20101214092512/http://eprint.iacr.org/2010/594.pdf |archive-date=2010-12-14}}</ref> Like some earlier attacks, this one requires the ability to run unprivileged code on the system performing the AES encryption, which may be achieved by malware infection far more easily than commandeering the root account.<ref>{{cite web |url=http://news.ycombinator.com/item?id=1937902 |title=Breaking AES-128 in realtime, no ciphertext required |publisher=Hacker News |access-date=2012-12-23 |url-status=live |archive-url=https://web.archive.org/web/20111003193004/http://news.ycombinator.com/item?id=1937902 |archive-date=2011-10-03}}</ref>

In March 2016, Ashokkumar C. Ashokkumar, Ravi Prakash Giri and Bernard Menezes presented a side-channel attack on AES implementations that can recover the complete 128-bit AES key in just 6–7 blocks of plaintext/ciphertext, which is a substantial improvement over previous works that require between 100 and a million encryptions.<ref>{{citeCite bookconference |yeardate=12 May 2016 |author1title=AshokkumarHighly C.Efficient Algorithms for AES Key Retrieval in Cache Access Attacks |titleconference=2016 IEEE European Symposium on Security and Privacy (EuroS&P) |last1=Ashokkumar |first1=C. |pages=261–275 |author2last2=Giri |first2=Ravi Prakash Giri|last3=Menezes |author3first3=Bernard Menezes|___location=Saarbruecken, Germany |doi=10.1109/EuroSP.2016.29 |isbn=978-1-5090-1751-5 |s2cid=11251391}}</ref> The proposed attack requires standard user privilege and key-retrieval algorithms run under a minute.

Many modern CPUs have built-in [[AES instruction set|hardware instructions for AES]], which protect against timing-related side-channel attacks.<ref>{{cite webconference |urllast1=httpsMowery |first1=Keaton |last2=Keelveedhi |first2=Sriram |last3=Shacham |first3=Hovav |conference=CCS'12://cseweb.ucsd.edu/~kmowery/papers/aes-cache-timing.pdf the ACM Conference on Computer and Communications Security |date=19 October 2012 |___location=Raleigh, North Carolina, USA |pages=19–24 |title=Are AES x86 Cachecache Timingtiming Attacksattacks Stillstill Feasiblefeasible? |websiteurl=https://cseweb.ucsd.edu |url/~kmowery/papers/aes-status=livecache-timing.pdf |archive-url=https://web.archive.org/web/20170809152309/http://cseweb.ucsd.edu/~kmowery/papers/aes-cache-timing.pdf |archive-date=2017-08-09 |doi=10.1145/2381913.2381917}}</ref><ref>{{cite web |url=https://www.intel.in/content/dam/doc/white-paper/enterprise-security-aes-ni-white-paper.pdf |title=Securing the Enterprise with Intel AES-NI |access-date=2017-07-26 |url-status=live |archive-url=https://web.archive.org/web/20130331041411/http://www.intel.in/content/dam/doc/white-paper/enterprise-security-aes-ni-white-paper.pdf |archive-date=2013-03-31 |website=[[Intel Corporation]]}}</ref>

=== Quantum attacks ===

AES-256 is considered to be [[QuantumPost-quantum computingcryptography|quantum]] resistant]], as it has similar quantum resistance to AES-128's resistance against traditional, non-quantum, attacks at 128 [[bits of security]]. AES-192 and AES-128 are not considered quantum resistant due to their smaller key sizes. AES-192 has a strength of 96 bits against quantum attacks and AES-128 has 64 bits of strength against quantum attacks, making them both insecure.<ref>{{cite journal |last1=Bonnetain |first1=Xavier |last2=Naya-Plasencia |first2=María |last3=Schrottenloher |first3=André |title=Quantum Security Analysis of AES |journal=IACR Transactions on Symmetric Cryptology |date=11 June 2019 |volume=2019 |issue=2 |pages=55–93 |doi=10.13154/tosc.v2019.i2.55-93 |doi-access= free |url=https://inria.hal.science/hal-02397049/document}}</ref><ref>{{Cite web |last=O'Shea |first=Dan |date=April 26, 2022 |title=AES-256 joins the quantum resistance |url=https://www.fierceelectronics.com/electronics/aes-256-joins-quantum-resistance |access-date=September 26, 2023 |website=Fierce Electronics}}</ref>

== NIST/CSEC validation ==

Line 180 ⟶ 185:

The Cryptographic Algorithm Validation Program (CAVP)<ref>{{cite web |url=http://csrc.nist.gov/groups/STM/cavp/index.html |title=NIST.gov – Computer Security Division – Computer Security Resource Center |publisher=Csrc.nist.gov |access-date=2012-12-23 |url-status=live |archive-url=https://web.archive.org/web/20130102044410/http://csrc.nist.gov/groups/STM/cavp/index.html |archive-date=2013-01-02}}</ref> allows for independent validation of the correct implementation of the AES algorithm. Successful validation results in being listed on the NIST validations page.<ref>{{cite web |url=http://csrc.nist.gov/groups/STM/cmvp/documents/140-1/140val-all.htm |title=Validated FIPS 140-1 and FIPS 140-2 Cryptographic Modules |url-status=dead |archive-url=https://web.archive.org/web/20141226152243/http://csrc.nist.gov/groups/STM/cmvp/documents/140-1/140val-all.htm |archive-date=2014-12-26 |access-date=2014-06-26}}</ref> This testing is a pre-requisite for the FIPS 140-2 module validation. However, successful CAVP validation in no way implies that the cryptographic module implementing the algorithm is secure. A cryptographic module lacking FIPS 140-2 validation or specific approval by the NSA is not deemed secure by the US Government and cannot be used to protect government data.<ref name="cnss.gov"/>

FIPS 140-2 validation is challenging to achieve both technically and fiscally.<ref name="openssl">{{cite web |author=OpenSSL, [e-mail] |url=http://openssl.org/docs/fips/fipsnotes.html |title=OpenSSL's Notes about FIPS certification |publisher=Openssl.org |access-date=2012-12-23 |url-status=dead |archive-url=https://web.archive.org/web/20130102203126/http://www.openssl.org/docs/fips/fipsnotes.html |archive-date=2013-01-02}}</ref> There is a standardized battery of tests as well as an element of source code review that must be passed over a period of a few weeks. The cost to perform these tests through an approved laboratory can be significant (e.g., well over $30,000 US{{currency|30000|USD}})<ref name="openssl" /> and does not include the time it takes to write, test, document and prepare a module for validation. After validation, modules must be re-submitted and re-evaluated if they are changed in any way. This can vary from simple paperwork updates if the security functionality did not change to a more substantial set of re-testing if the security functionality was impacted by the change.

== Test vectors ==

Line 220 ⟶ 225:

* [http://www.formaestudio.com/rijndaelinspector/archivos/Rijndael_Animation_v4_eng.swf Animation of Rijndael] – AES deeply explained and animated using Flash (by Enrique Zabala / University ORT / Montevideo / Uruguay). This animation (in English, Spanish, and German) is also part of [[CrypTool|CrypTool 1]] (menu Indiv. Procedures → Visualization of Algorithms → AES).

* [https://formaestudio.com/rijndaelinspector/archivos/Rijndael_Animation_v4_eng-html5.html HTML5 Animation of Rijndael] – Same Animation as above made in HTML5.

* [https://infsec.de/aes-in-excel-eng/ AES Demo in Excel] - Example implementation and demonstration in Excel (without macros) by Tim Wambach.

{{Cryptography navbox | block}}

Line 225 ⟶ 231:

[[Category:Advanced Encryption Standard]]

[[Category:Cryptography]]

[[Category:Belgian inventions]]