Editing Triple DES

{{Short description|Block cipher}}
{{Infobox block cipher
| name          = Triple Data Encryption Algorithm
| image         = 3des-overall-view.png
| caption       = 3DES overall view
| publish date  = 1981
| derived from  = [[Data Encryption Standard|DES]]
| key size      = 112 or 168 bits
| block size    = 64 bits
| structure     = [[Feistel network]]
| rounds        = 48 DES-equivalent rounds
| cryptanalysis = Lucks: 2<sup>32</sup> known plaintexts, 2<sup>113</sup> operations including 2<sup>90</sup> DES encryptions, 2<sup>88</sup> memory; Biham: find one of 2<sup>28</sup> target keys with a handful of chosen plaintexts per key and 2<sup>84</sup> encryptions}}

In [[cryptography]], '''Triple DES''' ('''3DES''' or '''TDES'''), officially the '''Triple Data Encryption Algorithm''' ('''TDEA''' or '''Triple DEA'''), is a [[symmetric-key]] [[block cipher]], which applies the [[Data Encryption Standard|DES]] cipher algorithm three times to each data block. The 56-bit key of the Data Encryption Standard (DES) is no longer considered adequate in the face of modern cryptanalytic techniques and supercomputing power; Triple DES increases the effective security to 112&nbsp;bits. A [[Common Vulnerabilities and Exposures|CVE]] released in 2016, ''[https://nvd.nist.gov/vuln/detail/CVE-2016-2183 CVE-2016-2183]'', disclosed a major security vulnerability in the DES and 3DES encryption algorithms. This CVE, combined with the inadequate key size of 3DES, led to [[NIST]] deprecating 3DES in 2019 and disallowing all uses (except processing already encrypted data) by the end of 2023.<ref>{{Cite web |last=Barker |first=Elaine |last2=Roginsky |first2=Allen |date=2019-03-01 |title=Transitioning the use of cryptographic algorithms and key lengths |url=https://nvlpubs.nist.gov/nistpubs/SpecialPublications/NIST.SP.800-131Ar2.pdf |access-date=2022-09-20 |archive-url=https://web.archive.org/web/20190511203915/https://nvlpubs.nist.gov/nistpubs/SpecialPublications/NIST.SP.800-131Ar2.pdf |archive-date=2019-05-11 |url-status=live |location=Gaithersburg, MD |publisher=NIST Publications |id=NIST SP 800-131A Revision 2 |page=7 |doi=10.6028/nist.sp.800-131ar2}}</ref> It has been replaced with the more secure, more robust [[Advanced Encryption Standard|AES]].

While US government and industry standards abbreviate the algorithm's name as TDES (Triple DES) and TDEA (Triple Data Encryption Algorithm),<ref>{{cite web
| url=https://www.ibm.com/support/knowledgecenter/SSLTBW_2.1.0/com.ibm.zos.v2r1.csfb400/gloss.htm#T
| title=Triple DES Encryption
| publisher=IBM
| access-date=2010-05-17}}</ref> RFC 1851 referred to it as 3DES from the time it first promulgated the idea, and this namesake has since come into wide use by most vendors, users, and cryptographers.<ref>{{cite journal
| arxiv=1003.4085
| title=New Comparative Study Between DES, 3DES and AES within Nine Factors
| journal=Journal of Computing
| volume=2
| issue=3
| date=March 2010
| issn=2151-9617
| bibcode=2010arXiv1003.4085A
| last1=Alanazi
| first1=Hamdan. O.
| last2=Zaidan
| first2=B. B.
| last3=Zaidan
| first3=A. A.
| last4=Jalab
| first4=Hamid A.
| last5=Shabbir
| first5=M.
| last6=Al-Nabhani
| first6=Y.
}}</ref><ref>{{cite web
| url=http://instrumentation.obs.carnegiescience.edu/FourStar/Documents/FourStar%20Commercial%20Manuals/CISCO%20PIX%20515E/PIX%20515E%20Getting%20Started%20Guide.pdf |archive-url=https://web.archive.org/web/20160207205956/http://instrumentation.obs.carnegiescience.edu/FourStar/Documents/FourStar%20Commercial%20Manuals/CISCO%20PIX%20515E/PIX%20515E%20Getting%20Started%20Guide.pdf |archive-date=2016-02-07 |url-status=live
| title=Cisco PIX 515E Security Appliance Getting Started Guide: Obtaining a DES License or a 3DES-AES License
| date=2006
| publisher=[[Cisco]]
| access-date=2017-09-05}}</ref><ref>{{cite web
| url=https://www.highbeam.com/doc/1G1-161420739.html
| archive-url=https://web.archive.org/web/20130510231256/http://www.highbeam.com/doc/1G1-161420739.html
| url-status=dead
| archive-date=2013-05-10
| title=3DES Update: Most Banks Are Done, But...
| work=ATM & Debit News
| date=2007-03-29
| access-date=2017-09-05}}</ref><ref>{{IETF RFC|2828|4949|leadout=and RFC}}</ref>

==History==

In 1978, a triple encryption method using DES with two 56-bit keys was proposed by [[Walter Tuchman]]; in 1981, [[Ralph Merkle|Merkle]] and [[Martin Hellman|Hellman]] proposed a more secure triple-key version of 3DES with 112&nbsp;bits of security.<ref>Merkle, R. and M. Hellman, "On the Security of Multiple Encryption", Communications of the ACM, vol. 24, no. 7, pp. 465–467, July 1981.</ref>

==Standards==

The Triple Data Encryption Algorithm is variously defined in several standards documents:

* [[Request for Comments|RFC]] 1851, ''The ESP Triple DES Transform''<ref>{{cite ietf
| title=The ESP Triple DES Transform
| rfc=1851
| first1=P.
| last1=Karn
| first2=P.
| last2=Metzger
| first3=W.
| last3=Simpson
| date=September 1995}}</ref> (approved in 1995)
* [[ANSI]] ANS X9.52-1998 ''Triple Data Encryption Algorithm Modes of Operation''<ref name="ANSIx952">{{cite web
| title=ANSI X9.52-1998 Triple Data Encryption Algorithm Modes of Operation 
| url=https://infostore.saiglobal.com/store/details.aspx?ProductID=205606
| url-access=subscription
| access-date=2017-09-05}} Extends ANSI X3.92-1981 ''Data Encryption Algorithm''.</ref> (approved in 1998, withdrawn in 2008<ref>{{cite magazine
| title=Notice of Withdrawal: ANS at least 10 years past approval date
| date=2008-11-14
| volume=39
| issue=46
| page=5
| magazine=ANSI Standards Action
| publisher=[[ANSI]]
| url=https://share.ansi.org/Shared%20Documents/Standards%20Action/2008%20PDFs/SAV3946.pdf |archive-url=https://web.archive.org/web/20170906134039/https://share.ansi.org/Shared%20Documents/Standards%20Action/2008%20PDFs/SAV3946.pdf |archive-date=2017-09-06 |url-status=live
| access-date=2017-09-05
| issn=0038-9633}}</ref>)
* [[Federal Information Processing Standards|FIPS]] PUB 46-3 ''Data Encryption Standard (DES)''<ref>{{cite web
| url=http://csrc.nist.gov/publications/fips/fips46-3/fips46-3.pdf |archive-url=https://web.archive.org/web/20030405225406/http://csrc.nist.gov/publications/fips/fips46-3/fips46-3.pdf |archive-date=2003-04-05 |url-status=live
| title=FIPS PUB 46-3: Data Encryption Standard (DES)
| date=Oct 25, 1999
| publisher=[[United States Department of Commerce]]
| access-date=2017-09-05}}</ref> (approved in 1999, withdrawn in 2005<ref>{{cite journal
| url=http://csrc.nist.gov/groups/STM/cmvp/documents/05-9945-DES-Withdrawl.pdf |archive-url=https://web.archive.org/web/20080917125417/http://csrc.nist.gov/groups/STM/cmvp/documents/05-9945-DES-Withdrawl.pdf |archive-date=2008-09-17 |url-status=live
| title=Announcing Approval of the Withdrawal of Federal Information Processing Standard (FIPS) 46–3....
| journal=[[Federal Register]]
| volume=70
| number=96
| date=2005-05-19
| access-date=2017-09-05}}</ref>)
* [[NIST]] Special Publication 800-67 Revision 2 ''Recommendation for the Triple Data Encryption Algorithm (TDEA) Block Cipher''<ref name="NIST67r2">{{cite web
| title=NIST Special Publication 800-67 Revision 2: Recommendation for the Triple Data Encryption Algorithm (TDEA) Block Cipher
| first1=Elaine
| last1=Barker
| first2=Nicky
| last2=Mouha
| publisher=[[NIST]]
| date=November 2017
| doi=10.6028/NIST.SP.800-67r2
| doi-access=free
| url=https://nvlpubs.nist.gov/nistpubs/SpecialPublications/NIST.SP.800-67r2.pdf
| access-date=2017-11-21
| archive-url=https://web.archive.org/web/20171201131807/https://nvlpubs.nist.gov/nistpubs/SpecialPublications/NIST.SP.800-67r2.pdf
| archive-date=2017-12-01
| url-status=live
}}</ref> (approved in 2017, withdrawn in 2024<ref>NIST to Withdraw Special Publication 800-67 Revision 2 https://csrc.nist.gov/news/2023/nist-to-withdraw-sp-800-67-rev-2</ref>)
* [[ISO]]/[[International Electrotechnical Commission|IEC]] 18033-3:2010: Part 3: Block ciphers<ref>{{cite web
| url=https://www.iso.org/standard/54531.html
| title=ISO/IEC 18033-3:2010 Information technology -- Security techniques -- Encryption algorithms -- Part 3: Block ciphers
| publisher=[[ISO]]
| date=December 2010
| access-date=2017-09-05}}</ref> (approved in 2005)

==Algorithm==
The original DES cipher's [[key size]] of 56&nbsp;bits was considered generally sufficient when it was designed, but the availability of increasing computational power made [[brute-force attack]]s feasible. Triple DES provides a relatively simple method of increasing the key size of DES to protect against such attacks, without the need to design a completely new block cipher algorithm.

A naive approach to increase the strength of a block encryption algorithm with a short key length (like DES) would be to use two keys <math>(K1, K2)</math> instead of one, and encrypt each block twice: <math>E_{K2}(E_{K1}(\textrm{plaintext}))</math>. If the original key length is <math>n</math> bits, one would hope this scheme provides security equivalent to using a key <math>2n</math> bits long. Unfortunately, this approach is vulnerable to the [[meet-in-the-middle attack]]: given a [[known plaintext]] pair <math>(x, y)</math>, such that <math>y = E_{K2}(E_{K1}(x))</math>, one can recover the key pair <math>(K1, K2)</math> in <math>2^{n+1}</math> steps, instead of the <math>2^{2n}</math> steps one would expect from an ideally secure algorithm with <math>2n</math> bits of key.

Therefore, Triple DES uses a "key bundle" that comprises three DES [[Key (cryptography)|keys]], <math>K1</math>, <math>K2</math> and <math>K3</math>, each of 56&nbsp;bits (excluding [[parity bit]]s). The encryption algorithm is:
: <math>\textrm{ciphertext} = E_{K3}(D_{K2}(E_{K1}(\textrm{plaintext}))).</math>
That is, encrypt with <math>K1</math>, <em>decrypt</em> with <math>K2</math>, then encrypt with <math>K3</math>.

Decryption is the reverse:
: <math>\textrm{plaintext} = D_{K1}(E_{K2}(D_{K3}(\textrm{ciphertext}))).</math>
That is, decrypt with <math>K3</math>, <em>encrypt</em> with <math>K2</math>, then decrypt with <math>K1</math>.

Each triple encryption encrypts one [[Block size (cryptography)|block]] of 64&nbsp;bits of data.

In each case, the middle operation is the reverse of the first and last. This improves the strength of the algorithm when using [[#Keying options|keying option]] 2 and provides [[backward compatibility]] with DES with keying option 3.

== Keying options ==
The standards define three keying options:
; Keying option 1
: All three keys are independent. Sometimes known as 3TDEA<ref name="NIST57r4">{{cite web
| url=http://nvlpubs.nist.gov/nistpubs/SpecialPublications/NIST.SP.800-57pt1r4.pdf |archive-url=https://web.archive.org/web/20160207114509/http://nvlpubs.nist.gov/nistpubs/SpecialPublications/NIST.SP.800-57pt1r4.pdf |archive-date=2016-02-07 |url-status=live
| title=NIST Special Publication 800-57: Recommendation for Key Management Part 1: General
| first=Elaine
| last=Barker
| edition=4
| date=January 2016
| publisher=[[NIST]]
| access-date=2017-09-05}}</ref> or triple-length keys.<ref name=cryptography_world>{{cite web
| url=http://www.cryptographyworld.com/des.htm
| title=The Cryptography Guide: Triple DES
| publisher=Cryptography World
| archive-url=https://web.archive.org/web/20170312125442/http://www.cryptographyworld.com/des.htm
| archive-date=2017-03-12
| url-status=dead
| access-date=2017-09-05}}</ref><!--
--><p>This is the strongest, with 3 × 56 = 168 independent key bits. It is still vulnerable to the [[meet-in-the-middle attack]], but the attack requires 2<sup>2 × 56</sup> steps.</p>
; Keying option 2
: K<sub>1</sub> and K<sub>2</sub> are independent, and K<sub>3</sub> = K<sub>1</sub>. Sometimes known as 2TDEA<ref name="NIST57r4"/> or double-length keys.<ref name=cryptography_world/><!--
--><p>This provides a shorter key length of 56 × 2 or 112&nbsp;bits and a reasonable compromise between DES and keying option 1, with the same caveat as above.<ref>{{cite book
| title=Introduction to Modern Cryptography
| first1=Jonathan
| last1=Katz
| first2=Yehuda
| last2=Lindell
| date=2015
| publisher=[[CRC Press|Chapman and Hall/CRC]]
| page=223
| isbn=9781466570269}}</ref> This is an improvement over "double DES" which only requires 2<sup>56</sup> steps to attack. NIST disallowed this option in 2015.<ref name="NIST57r4"/></p>
; Keying option 3
: All three keys are identical, i.e. K<sub>1</sub> = K<sub>2</sub> = K<sub>3</sub>.<!--
--><p>This is backward-compatible with DES, since two of the operations cancel out. ISO/IEC 18033-3 never allowed this option, and NIST no longer allows K<sub>1</sub> = K<sub>2</sub> or K<sub>2</sub> = K<sub>3</sub>.<ref name="NIST57r4" /><ref name="NIST67r2" /></p>

Each DES key is 8 [[odd parity|odd-parity]] bytes, with 56&nbsp;bits of key and 8&nbsp;bits of error-detection.<ref name="ANSIx952"/> A key bundle requires 24&nbsp;bytes for option 1, 16 for option 2, or 8 for option 3.

NIST (and the current TCG specifications version 2.0 of approved algorithms for [[Trusted Platform Module]]) also disallows using any one of the 64 following 64-bit values in any keys (note that 32 of them are the binary complement of the 32 others; and that 32 of these keys are also the reverse permutation of bytes of the 32 others), listed here in hexadecimal (in each byte, the least significant bit is an odd-parity generated bit, which is discarded when forming the effectively 56-bit key):
 01.01.01.01.01.01.01.01, FE.FE.FE.FE.FE.FE.FE.FE, E0.FE.FE.E0.F1.FE.FE.F1, 1F.01.01.1F.0E.01.01.0E,
 01.01.FE.FE.01.01.FE.FE, FE.FE.01.01.FE.FE.01.01, E0.FE.01.1F.F1.FE.01.0E, 1F.01.FE.E0.0E.01.FE.F1,
 01.01.E0.E0.01.01.F1.F1, FE.FE.1F.1F.FE.FE.0E.0E, E0.FE.1F.01.F1.FE.0E.01, 1F.01.E0.FE.0E.01.F1.FE,
 01.01.1F.1F.01.01.0E.0E, FE.FE.E0.E0.FE.FE.F1.F1, E0.FE.E0.FE.F1.FE.F1.FE, 1F.01.1F.01.0E.01.0E.01,
 01.FE.01.FE.01.FE.01.FE, FE.01.FE.01.FE.01.FE.01, E0.01.FE.1F.F1.01.FE.0E, 1F.FE.01.E0.0E.FE.01.F1,
 01.FE.FE.01.01.FE.FE.01, FE.01.01.FE.FE.01.01.FE, E0.01.01.E0.F1.01.01.F1, 1F.FE.FE.1F.0E.FE.FE.0E,
 01.FE.E0.1F.01.FE.F1.0E, FE.01.1F.E0.FE.01.0E.F1, E0.01.1F.FE.F1.01.0E.FE, 1F.FE.E0.01.0E.FE.F1.01,
 01.FE.1F.E0.01.FE.0E.F1, FE.01.E0.1F.FE.01.F1.0E, E0.01.E0.01.F1.01.F1.01, 1F.FE.1F.FE.0E.FE.0E.FE,
 01.E0.01.E0.01.F1.01.F1, FE.1F.FE.1F.FE.0E.FE.0E, E0.1F.FE.01.F1.0E.FE.01, 1F.E0.01.FE.0E.F1.01.FE,
 01.E0.FE.1F.01.F1.FE.0E, FE.1F.01.E0.FE.0E.01.F1, E0.1F.01.FE.F1.0E.01.FE, 1F.E0.FE.01.0E.F1.FE.01,
 01.E0.E0.01.01.F1.F1.01, FE.1F.1F.FE.FE.0E.0E.FE, E0.1F.1F.E0.F1.0E.0E.F1, 1F.E0.E0.1F.0E.F1.F1.0E,
 01.E0.1F.FE.01.F1.0E.FE, FE.1F.E0.01.FE.0E.F1.01, E0.1F.E0.1F.F1.0E.F1.0E, 1F.E0.1F.E0.0E.F1.0E.F1,
 01.1F.01.1F.01.0E.01.0E, FE.E0.FE.E0.FE.F1.FE.F1, E0.E0.FE.FE.F1.F1.FE.FE, 1F.1F.01.01.0E.0E.01.01,
 01.1F.FE.E0.01.0E.FE.F1, FE.E0.01.1F.FE.F1.01.0E, E0.E0.01.01.F1.F1.01.01, 1F.1F.FE.FE.0E.0E.FE.FE,
 01.1F.E0.FE.01.0E.F1.FE, FE.E0.1F.01.FE.F1.0E.01, E0.E0.1F.1F.F1.F1.0E.0E, 1F.1F.E0.E0.0E.0E.F1.F1,
 01.1F.1F.01.01.0E.0E.01, FE.E0.E0.FE.FE.F1.F1.FE, E0.E0.E0.E0.F1.F1.F1.F1, 1F.1F.1F.1F.0E.0E.0E.0E
With these restrictions on allowed keys, Triple DES was reapproved with keying options 1 and 2 only. Generally, the three keys are generated by taking 24&nbsp;bytes from a strong random generator, and only keying option 1 should be used (option 2 needs only 16 random bytes, but strong random generators are hard to assert and it is considered best practice to use only option 1).

==Encryption of more than one block==
As with all block ciphers, encryption and decryption of multiple blocks of data may be performed using a variety of [[modes of operation]], which can generally be defined independently of the block cipher algorithm. However, ANS X9.52 specifies directly, and NIST SP 800-67 specifies via SP 800-38A,<ref>[http://csrc.nist.gov/publications/nistpubs/800-38a/sp800-38a.pdf NIST Special Publication 800-38A, ''Recommendation for Block Cipher Modes of Operation, Methods and Techniques'', 2001 Edition] (PDF)</ref> that some modes shall only be used with certain constraints on them that do not necessarily apply to general specifications of those modes. For example, ANS X9.52 specifies that for [[cipher block chaining]], the [[initialization vector]] shall be different each time, whereas ISO/IEC 10116<ref>{{cite web
| url=https://www.iso.org/standard/38761.html
| title=ISO/IEC 10116:2006 Information technology -- Security techniques -- Modes of operation for an n-bit block cipher
| edition=3
| date=February 2006
| access-date=2017-09-05}}</ref> does not. FIPS PUB 46-3 and ISO/IEC 18033-3 define only the single-block algorithm, and do not place any restrictions on the modes of operation for multiple blocks.

==Security==
In general, Triple DES with three independent keys ([[#Keying options|keying option]]&nbsp;1) has a key length of 168&nbsp;bits (three 56-bit DES keys), but due to the [[meet-in-the-middle attack]], the effective security it provides is only 112&nbsp;bits.<ref name="NIST57r4" /> Keying option&nbsp;2 reduces the effective key size to 112&nbsp;bits (because the third key is the same as the first). However, this option is susceptible to certain [[chosen-plaintext]] or [[known-plaintext]] attacks,<ref>{{cite journal | author-link1 = Ralph Merkle | first = Ralph | last1 = Merkle | author-link2 = Martin Hellman | first2 = Martin | last2 = Hellman | url = http://cs.jhu.edu/~sdoshi/crypto/papers/p465-merkle.pdf | title = On the Security of Multiple Encryption | journal = [[Communications of the ACM]] | volume = 24 | issue = 7 | pages = 465–467 | date = July 1981 | doi = 10.1145/358699.358718 | citeseerx = 10.1.1.164.251 | s2cid = 11583508 | access-date = 2013-11-15 | archive-date = 2013-02-10 | archive-url = https://web.archive.org/web/20130210011347/http://cs.jhu.edu/~sdoshi/crypto/papers/p465-merkle.pdf | url-status = dead }}</ref><ref>{{cite conference | author-link1 = Paul van Oorschot | first1 = Paul | last1 = van Oorschot | author-link2 = Michael J. Wiener | first2 = Michael J. | last2 = Wiener | citeseerx = 10.1.1.66.6575 | title = A known-plaintext attack on two-key triple encryption | conference = [[EUROCRYPT]]'90, LNCS 473 | year = 1990 | pages = 318–325 }}</ref> and thus it is designated by NIST to have only 80&nbsp;[[bits of security]].<ref name="NIST57r4" /> This can be considered insecure; as a consequence, Triple DES's planned deprecation was announced by NIST in 2017.<ref name="tdea-deprecation">{{cite web |title=Update to Current Use and Deprecation of TDEA |url=https://csrc.nist.gov/News/2017/Update-to-Current-Use-and-Deprecation-of-TDEA |website=nist.gov |date=11 July 2017 |access-date=2 August 2019}}</ref>

[[Image:Sweet32.svg|thumb|right|Logo of the Sweet32 attack]]

The short block size of 64&nbsp;bits makes 3DES vulnerable to block collision attacks if it is used to encrypt large amounts of data with the same key. The Sweet32 attack shows how this can be exploited in TLS and OpenVPN.<ref>{{Cite web
| url=https://sweet32.info/
| title=Sweet32: Birthday attacks on 64-bit block ciphers in TLS and OpenVPN
| website=sweet32.info
| access-date=2017-09-05}}</ref> Practical Sweet32 attack on 3DES-based cipher-suites in TLS required <math>2^{36.6}</math> blocks (785&nbsp;GB) for a full attack, but researchers were lucky to get a collision just after around <math>2^{20}</math> blocks, which took only 25&nbsp;minutes.

{{Blockquote
|text=The security of TDEA is affected by the number of blocks processed with one key bundle. One key bundle shall not be used to apply cryptographic protection (e.g., encrypt) more than <math>2^{20}</math> 64-bit data blocks.
|sign=
|source=Recommendation for Triple Data Encryption Algorithm (TDEA) Block Cipher (SP 800-67 Rev2)<ref name="NIST67r2" />}}

[[OpenSSL]] does not include 3DES by default since version 1.1.0 (August 2016) and considers it a "weak cipher".<ref>{{cite web
| url=https://openssl-library.org/post/2016-08-25-sweet32/
| title=The SWEET32 Issue, CVE-2016-2183
| first=Rich
| last=Salz
| date=2016-08-24
| publisher=[[OpenSSL]]
| access-date=2024-10-11}}</ref>

==Usage==
As of 2008, the [[electronic payment]] industry uses Triple DES and continues to develop and promulgate standards based upon it, such as [[EMV]].<ref>{{cite book
| title=EMV 4.2: Book 2 – Security and Key Management
| date=June 2008
| publisher=[[EMVCo]]
| page=137
| chapter=Annex B Approved Cryptographic Algorithms – B1.1 Data Encryption Standard (DES)
| chapter-url=http://www.emvco.com/specifications.aspx?id=155
| edition=4.2
| quote=The double-length key triple DES encipherment algorithm (see ISO/IEC 18033-3) is the approved cryptographic algorithm to be used in the encipherment and MAC mechanisms specified in Annex A1. The algorithm is based on the (single) DES algorithm standardised in ISO 16609.
| access-date=2009-03-21
| archive-date=2017-07-18
| archive-url=https://web.archive.org/web/20170718005134/http://emvco.com/specifications.aspx?id=155
| url-status=dead
}}</ref>

Earlier versions of [[Microsoft OneNote]],<ref>{{cite web |last=Escapa |first=Daniel |date=2006-11-09 |title=Encryption for Password Protected Sections |work=Daniel Escapa's OneNote Blog |url=https://learn.microsoft.com/en-us/archive/blogs/descapa/encryption-for-password-protected-sections |access-date=2010-01-28 |archive-url=https://web.archive.org/web/20091216150415/http://blogs.msdn.com/descapa/archive/2006/11/09/encryption-for-password-protected-sections.aspx |archive-date=2009-12-16 |url-status=live}}</ref> [[Microsoft Outlook]] 2007<ref>{{cite web |url=http://office.microsoft.com/en-us/outlook/HP012305361033.aspx |title=Encrypt e-mail messages – Outlook – Microsoft Office Online |quote=Applies to: Microsoft Office Outlook 2007 |website=office.microsoft.com |archive-url=https://web.archive.org/web/20081225033340/http://office.microsoft.com/en-us/outlook/HP012305361033.aspx |archive-date=2008-12-25 |url-status=dead }}</ref> and Microsoft [[System Center Configuration Manager]] 2012<ref>Microsoft TechNet product documentation, [https://technet.microsoft.com/en-us/library/hh427327.aspx Technical Reference for Cryptographic Controls Used in Configuration Manager], October 2012.</ref> use Triple DES to password-protect user content and system data. However, in December 2018, Microsoft announced the retirement of 3DES throughout their Office 365 service.<ref>{{Cite web |title=Admin Portal |url=https://portal.office.com/AdminPortal/home?switchtomodern=true#/MessageCenter?id=MC171089 |access-date=2023-03-14 |website=portal.office.com}}</ref>

[[Firefox]] and [[Mozilla Thunderbird]] use Triple DES in [[CBC mode]] to encrypt website authentication login credentials when using a master password.<ref>[https://dxr.mozilla.org/mozilla-central/source/security/nss/lib/pk11wrap/pk11sdr.c#248 Mozilla NSS source code]. See [https://developer.mozilla.org/en-US/docs/Mozilla/Developer_guide/Source_Code/Directory_structure Explanation of directory structure] (especially the introductory and "security" sections) for background information.</ref>

== Implementations ==
Below is a list of cryptography libraries that support Triple DES:

* [[Botan (programming library)|Botan]]
* [[Bouncy Castle (cryptography)|Bouncy Castle]]
* [[cryptlib]]
* [[Crypto++]]
* [[Libgcrypt]]
* [[Nettle (cryptographic library)|Nettle]]
* [[OpenSSL]]
* [[wolfSSL]]
* [[Trusted Platform Module]] (TPM)

Some implementations above may not include 3DES in the default build, in later or more recent versions, but may still support decryption in order to handle existing data.

==See also==
* [[DES-X]]
* [[Advanced Encryption Standard]] (AES)
* [[Feistel cipher]]
* [[Walter Tuchman]]

==References and notes==
{{reflist|30em}}

{{Cryptography navbox | block}}

[[Category:Broken block ciphers]]
[[Category:Data Encryption Standard]]