Editing Server Message Block (section)

== History ==

=== SMB 1.0 ===
Barry Feigenbaum originally designed SMB at [[IBM]] in early 1983 with the aim of turning [[DOS]] [[INT 21h]] local file access into a networked file system.<ref name='tridgemyths'>{{cite web|url=https://www.samba.org/samba/docs/myths_about_samba.html|title=Myths About Samba|author=Tridgell, Andrew|author-link=Andrew Tridgell|access-date=January 3, 2016|archive-url=https://web.archive.org/web/20171020045502/https://www.samba.org/samba/docs/myths_about_samba.html|archive-date=October 20, 2017|url-status=live}}</ref> [[Microsoft]] made considerable modifications to the most commonly used version and included SMB support in the [[LAN Manager]] operating system it had started developing for [[OS/2]] with [[3Com]] around 1990.<ref name="theregister/2018/06/08/smb1">{{cite news |last1=Speed |first1=Richard |title=Have to use SMB 1.0? Windows 10 April 2018 Update says NO |url=https://www.theregister.com/2018/06/08/windows_10_smb1/ |access-date=18 February 2023 |work=[[theregister.com]] |language=en |archive-date=18 February 2023 |archive-url=https://web.archive.org/web/20230218011417/https://www.theregister.com/2018/06/08/windows_10_smb1/ |url-status=live }}</ref><ref name="borncity/2017/06/15/retire-smbv1">{{cite news |author1=guenni |title=Microsoft plans to deactivate SMBv1 in Windows 10 V1709 |url=https://borncity.com/win/2017/06/15/microsoft-plans-to-retire-smbv1-in-fall-in-windows-10/ |access-date=18 February 2023 |work=Born's Tech and Windows World |date=15 June 2017 |archive-date=18 February 2023 |archive-url=https://web.archive.org/web/20230218011414/https://borncity.com/win/2017/06/15/microsoft-plans-to-retire-smbv1-in-fall-in-windows-10/ |url-status=live }}</ref><ref name="thurrott/265909">{{cite news |last1=Giret |first1=Laurent |title=Microsoft Gets Ready to Disable SMB1 Protocol on Windows 11 |url=https://www.thurrott.com/windows/265909/microsoft-gets-ready-to-disable-smb1-protocol-on-windows-11 |access-date=18 February 2023 |work=Thurrott.com |date=20 April 2022 |archive-date=31 May 2024 |archive-url=https://web.archive.org/web/20240531142913/https://www.thurrott.com/windows/265909/microsoft-gets-ready-to-disable-smb1-protocol-on-windows-11 |url-status=live }}</ref> Microsoft continued to add features to the protocol in [[Windows for Workgroups]] ({{circa|1992}}) and in later versions of Windows. LAN Manager authentication was implemented based on the original legacy SMB specification's requirement to use IBM "LAN Manager" passwords, but implemented [[Data Encryption Standard|DES]] in a [[LM hash#Security weaknesses|flawed manner]] that allowed passwords to be cracked.<ref>{{cite web|author=Christopher Hertel|year=1999|title=SMB: The Server Message Block Protocol|url=http://ubiqx.org/cifs/SMB.html|url-status=live|archive-url=https://web.archive.org/web/20100310140946/http://ubiqx.org/cifs/SMB.html|archive-date=March 10, 2010|access-date=November 1, 2009}}</ref> Later, [[Kerberos (protocol)|Kerberos]] authentication was also added. The [[Windows domain]] logon protocols initially used [[40-bit encryption]] outside of the [[United States]], because of export restrictions on stronger 128-bit encryption<ref>{{cite web|date=November 1, 2006|title=Description of Microsoft Windows Encryption Pack 1|url=http://support.microsoft.com/kb/159709|url-status=live|archive-url=https://web.archive.org/web/20091002075623/http://support.microsoft.com/kb/159709|archive-date=October 2, 2009|access-date=November 1, 2009|publisher=[[Microsoft]]}}</ref> (subsequently lifted in 1996 when President [[Bill Clinton]] signed {{Ws2|Executive Order 13026}}<ref>{{cite web|year=1996|title=US Executive Order 13026|url=http://www.gpo.gov/fdsys/pkg/WCPD-1996-11-18/pdf/WCPD-1996-11-18-Pg2399.pdf|url-status=live|archive-url=https://web.archive.org/web/20091010125029/http://www.gpo.gov/fdsys/pkg/WCPD-1996-11-18/pdf/WCPD-1996-11-18-Pg2399.pdf|archive-date=October 10, 2009|access-date=November 1, 2009|publisher=[[United States Government]]}}</ref>).

SMB 1.0 (or SMB1) was originally designed to run on [[NetBIOS Frames]] (NetBIOS over [[IEEE 802.2]]). Since then, it has been adapted to NetBIOS over [[IPX/SPX]] (NBX), and [[NetBIOS over TCP/IP]] (NetBT). Also, since [[Windows 2000]], SMB runs on [[Transmission Control Protocol|TCP]] using TCP port 445, a feature known as "direct host SMB".<ref name="direct">{{cite web|url=http://support.microsoft.com/kb/204279|title=Direct hosting of SMB over TCP/IP|date=October 11, 2007|publisher=[[Microsoft]]|access-date=November 1, 2009|archive-url=https://web.archive.org/web/20110326164716/http://support.microsoft.com/kb/204279|archive-date=March 26, 2011|url-status=live}}</ref> There is still a thin layer (similar to the Session Message packet of NetBT's Session Service) between SMB and TCP.<ref name="direct" /> Windows Server 2003, and legacy [[Network-attached storage|NAS]] devices use SMB1 natively.

SMB1 is an extremely chatty protocol, which is not such an issue on a [[local area network]] (LAN) with low latency.  It becomes very slow on [[Wide area network|wide area networks]] (WAN) as the back and forth handshake of the protocol magnifies the inherent high latency of such a network. Later versions of the protocol reduced the high number of handshake exchanges. One approach to mitigating the inefficiencies in the protocol is to use [[WAN optimization]] products such as those provided by [[Riverbed Technology|Riverbed]], [[Silver Peak Systems|Silver Peak]], or [[Cisco Systems|Cisco]]. A better approach is to upgrade to a later version of SMB. This includes upgrading both NAS devices as well as Windows Server 2003. The most effective method to identify SMB1 traffic is with a network analyzer tool, such as [[Wireshark]].  Microsoft also provides an auditing tool in [[Windows Server 2016]] to track down devices that use SMB1.<ref name="messageanalyzer">{{cite web |last1=Kyttle |first1=Ralph |title=SMB1 – Audit Active Usage using Message Analyzer |url=https://blogs.technet.microsoft.com/ralphkyttle/2017/05/13/smb1-audit-active-usage-using-message-analyzer/ |website=Microsoft TechNet |publisher=Microsoft |access-date=28 March 2019 |date=13 May 2017 |archive-url=https://web.archive.org/web/20190328223802/https://blogs.technet.microsoft.com/ralphkyttle/2017/05/13/smb1-audit-active-usage-using-message-analyzer/ |archive-date=March 28, 2019 |url-status=live }}</ref>

Microsoft has marked SMB1 as [[deprecation|deprecated]] in June 2013.<ref>{{Cite web|title=The Deprecation of SMB1 – You should be planning to get rid of this old SMB dialect – Jose Barreto's Blog|url=https://blogs.technet.microsoft.com/josebda/2015/04/21/the-deprecation-of-smb1-you-should-be-planning-to-get-rid-of-this-old-smb-dialect/|url-status=live|archive-url=https://web.archive.org/web/20170521154946/https://blogs.technet.microsoft.com/josebda/2015/04/21/the-deprecation-of-smb1-you-should-be-planning-to-get-rid-of-this-old-smb-dialect/|archive-date=May 21, 2017|access-date=2019-10-09|website=blogs.technet.microsoft.com|date=21 April 2015 }}</ref> Windows Server 2016 and [[Windows 10 version 1709]] do not have SMB1 installed by default.<ref>{{Cite web|title=SMBv1 is not installed by default in Windows 10 Fall Creators Update and Windows Server, version 1709 and later versions|url=https://support.microsoft.com/en-us/help/4034314/smbv1-is-not-installed-by-default-in-windows|url-status=live|archive-url=https://web.archive.org/web/20191010052046/https://support.microsoft.com/en-us/help/4034314/smbv1-is-not-installed-by-default-in-windows|archive-date=October 10, 2019|access-date=2019-10-09|website=support.microsoft.com}}</ref>

=== CIFS ===
In 1996, when Sun Microsystems announced [[WebNFS]],<ref name="WebNFS">{{cite web |title=WebNFS - Technical Overview |url=http://www.sun.com/software/webnfs/overview.xml |archive-url=https://web.archive.org/web/20070518204025/http://www.sun.com/software/webnfs/overview.xml |archive-date=2007-05-18}}</ref> Microsoft launched an initiative to rename SMB to Common Internet File System (CIFS)<ref name="tridgemyths" /> and added more features, including support for [[symbolic link]]s, [[hard link]]s, larger file sizes, and an initial attempt at supporting direct connections over TCP port 445 without requiring [[NetBIOS]] as a transport (a largely experimental effort that required further refinement). Microsoft submitted some partial specifications as [[Internet Draft]]s to the [[Internet Engineering Task Force|IETF]].<ref name="IETF">See:
* {{cite web|first1=I.|last1=Heizer|first2=P.|last2=Leach|first3=D.|last3=Perry|date=June 13, 1996|title=Common Internet File System Protocol (CIFS/1.0)|url=https://tools.ietf.org/html/draft-heizer-cifs-v1-spec-00|url-status=dead|archive-url=https://web.archive.org/web/20190808115512/https://tools.ietf.org/html/draft-heizer-cifs-v1-spec-00|archive-date=August 8, 2019}}
* {{cite web|first1=Paul J.|last1=Leach|first2=Dilip C.|last2=Naik|date=January 3, 1997|title=CIFS Logon and Pass Through Authentication|url=http://tools.ietf.org/html/draft-leach-cifs-logon-spec|access-date=December 10, 2017|archive-date=May 31, 2024|archive-url=https://web.archive.org/web/20240531142914/https://datatracker.ietf.org/doc/html/draft-leach-cifs-logon-spec|url-status=live}}
* {{cite web|first1=Paul J.|last1=Leach|first2=Dilip C.|last2=Naik|date=January 10, 1997|title=CIFS/E Browser Protocol|url=http://tools.ietf.org/html/draft-leach-cifs-browser-spec|access-date=December 10, 2017|archive-date=May 31, 2024|archive-url=https://web.archive.org/web/20240531142914/https://datatracker.ietf.org/doc/html/draft-leach-cifs-browser-spec|url-status=live}}
* {{cite web|first1=Paul J.|last1=Leach|first2=Dilip C.|last2=Naik|date=January 31, 1997|title=CIFS Printing Specification|url=http://tools.ietf.org/html/draft-leach-cifs-print-spec|access-date=December 10, 2017|archive-date=May 31, 2024|archive-url=https://web.archive.org/web/20240531142916/https://datatracker.ietf.org/doc/html/draft-leach-cifs-print-spec|url-status=live}}
* {{cite web|first1=Paul J.|last1=Leach|first2=Dilip C.|last2=Naik|date=February 26, 1997|title=CIFS Remote Administration Protocol|url=http://tools.ietf.org/html/draft-leach-cifs-rap-spec|access-date=December 10, 2017|archive-date=May 31, 2024|archive-url=https://web.archive.org/web/20240531142915/https://datatracker.ietf.org/doc/html/draft-leach-cifs-rap-spec|url-status=live}}
* {{cite web|first1=Paul J.|last1=Leach|first2=Dilip C.|last2=Naik|date=December 19, 1997|title=A Common Internet File System (CIFS/1.0) Protocol|url=https://tools.ietf.org/html/draft-leach-cifs-v1-spec|access-date=December 10, 2017|archive-date=May 31, 2024|archive-url=https://web.archive.org/web/20240531142916/https://datatracker.ietf.org/doc/html/draft-leach-cifs-v1-spec|url-status=live}}</ref> These submissions have since expired.

=== SMB 2.0 ===
Microsoft introduced a new version of the protocol (SMB 2.0 or SMB2) in 2006 with [[Windows Vista]] and [[Windows Server 2008]].<ref name="smb2">{{cite web | url=http://blogs.msdn.com/chkdsk/archive/2006/03/10/548787.aspx | title=What's new in SMB in Windows Vista | date=March 10, 2006 | access-date=May 1, 2006 | author=Navjot Virk and Prashanth Prahalad | work=Chk Your Dsks | publisher=[[Microsoft]] | url-status=dead | archive-url=https://web.archive.org/web/20060505005515/http://blogs.msdn.com/chkdsk/archive/2006/03/10/548787.aspx | archive-date=May 5, 2006 | df=mdy-all }}</ref> Although the protocol is proprietary, its specification has been published to allow other systems to interoperate with Microsoft operating systems that use the new protocol.<ref>{{cite tech report |url=https://docs.microsoft.com/openspecs/windows_protocols/ms-smb2 |title=Server Message Block (SMB) Protocol Versions 2 and 3 |department=Windows Protocols |work=Open Specifications |series=[[Microsoft Docs]] |institution=[[Microsoft]] |number=MS-SMB2 |access-date=2020-11-29}}</ref>

SMB2 reduces the 'chattiness' of the SMB 1.0 protocol by reducing the number of commands and subcommands from over a hundred to just nineteen.<ref name="barreto"/> It has mechanisms for [[Pipeline (computing)|pipelining]], that is, sending additional requests before the response to a previous request arrives, thereby improving performance over high-[[Network latency|latency]] links. It adds the ability to compound multiple actions into a single request, which significantly reduces the number of [[round-trip delay time|round-trips]] the client needs to make to the server, improving performance as a result.<ref name="barreto"/> SMB1 also has a compounding mechanism—known as AndX—to compound multiple actions, but Microsoft clients rarely use AndX.{{Citation needed|date=November 2010}} It also introduces the notion of "durable file handles": these allow a connection to an SMB server to survive brief network outages, as are typical in a wireless network, without having to incur the overhead of re-negotiating a new session.

SMB2 includes support for [[symbolic link]]s. Other improvements include caching of file properties, improved message signing with [[HMAC]] [[SHA-256]] hashing algorithm and better scalability by increasing the number of users, shares and open files per server among others.<ref name="barreto"/> The SMB1 protocol uses 16-bit data sizes, which amongst other things, limits the maximum block size to 64K. SMB2 uses 32- or 64-bit wide storage fields, and 128 bits in the case of [[file handle|file-handle]]s, thereby removing previous constraints on block sizes, which improves performance with large file transfers over fast networks.<ref name="barreto"/>

Windows Vista/[[Server 2008]] and later operating systems use SMB2 when communicating with other machines also capable of using SMB2. SMB1 continues in use for connections with older versions of Windows, as well various vendors' [[Network-attached storage|NAS]] solutions. Samba 3.5 also includes experimental support for SMB2.<ref>{{Cite web |url=http://www.samba.org/samba/history/samba-3.5.0.html |title=Samba 3.5.0 Available for Download |access-date=July 8, 2011 |archive-url=https://web.archive.org/web/20110724051402/http://www.samba.org/samba/history/samba-3.5.0.html |archive-date=July 24, 2011 |url-status=live }}</ref> Samba 3.6 fully supports SMB2, except the modification of user quotas using the Windows quota management tools.<ref>{{Cite web |url=http://samba.org/samba/history/samba-3.6.0.html |title=Samba 3.6.0 Available for Download |access-date=August 10, 2011 |archive-url=https://web.archive.org/web/20110924042737/http://www.samba.org/samba/history/samba-3.6.0.html |archive-date=September 24, 2011 |url-status=live }}</ref>

When SMB2 was introduced it brought a number of benefits over SMB1 for third party implementers of SMB protocols. SMB1, originally designed by [[IBM]], was [[reverse engineering|reverse engineered]], and later became part of a wide variety of non-Windows operating systems such as [[Xenix]], [[OS/2]] and [[OpenVMS|VMS]] ([[Pathworks]]). [[X/Open]] standardized it partially; Microsoft had submitted Internet-Drafts describing SMB2 to the [[Internet Engineering Task Force|IETF]], partly in response to formal IETF standardization of version 4 of the [[Network File System]] in December 2000 as IETF RFC 3010;<ref>{{cite IETF|rfc=3010|title=NFS version 4 Protocol|date=December 2000}}</ref> however, those SMB-related Internet-Drafts expired without achieving any IETF standards-track approval or any other IETF endorsement. (See http://ubiqx.org/cifs/Intro.html for historical detail.) SMB2 is also a relatively clean break with the past. Microsoft's SMB1 code has to work with a large variety of SMB clients and servers. SMB1 features many versions of information for commands (selecting what structure to return for a particular request) because features such as [[Unicode]] support were retro-fitted at a later date. SMB2 involves significantly reduced compatibility-testing for implementers of the protocol. SMB2 code has considerably less complexity since far less variability exists (for example, non-Unicode code paths become redundant as SMB2 requires Unicode support).

Apple migrated to SMB2 (from their own [[Apple Filing Protocol]], now legacy) starting with [[OS X Mavericks|OS X 10.9 "Mavericks"]].<ref name="ai2013">{{cite web |last=Eran |first=Daniel |url=http://appleinsider.com/articles/13/06/11/apple-shifts-from-afp-file-sharing-to-smb2-in-os-x-109-mavericks |title=Apple shifts from AFP file sharing to SMB2 in OS X 10.9 Mavericks |publisher=Appleinsider.com |date=June 11, 2013 |access-date=January 12, 2014 |archive-url=https://web.archive.org/web/20170212162139/http://appleinsider.com/articles/13/06/11/apple-shifts-from-afp-file-sharing-to-smb2-in-os-x-109-mavericks |archive-date=February 12, 2017 |url-status=live }}</ref> This transition was fraught with compatibility problems though.<ref>{{cite web |last=Vaughan |first=Steven J. |url=https://www.zdnet.com/article/mavericks-smb2-problem-and-fixes/ |title=Mavericks' SMB2 problem and fixes |publisher=ZDNet |date=October 28, 2013 |access-date=January 12, 2014 |archive-url=https://web.archive.org/web/20140105011410/http://www.zdnet.com/mavericks-smb2-problem-and-fixes-7000022519/ |archive-date=January 5, 2014 |url-status=live }}</ref><ref>{{cite web |author=MacParc |url=http://hints.macworld.com/article.php?story=20131122083837447 |title=10.9: Switch the SMB stack to use SMB1 as default |work=Mac OS X Hints |publisher=macworld.com |access-date=January 12, 2014 |archive-url=https://web.archive.org/web/20140112051604/http://hints.macworld.com/article.php?story=20131122083837447 |archive-date=January 12, 2014 |url-status=live }}</ref> Non-default support for SMB2 appeared in fact in OS X 10.7, when Apple abandoned Samba in favor of its own SMB implementation called SMBX<ref name="ai2013"/> after Samba adopted [[GPLv3]].<ref>{{cite web|url=http://reviews.cnet.com/8301-13727_7-20046383-263.html|title=Say adios to Samba in OS X|author=Topher Kessler|date=March 23, 2011|publisher=CNET|access-date=January 12, 2014|archive-url=https://web.archive.org/web/20140115220216/http://reviews.cnet.com/8301-13727_7-20046383-263.html|archive-date=January 15, 2014|url-status=live}}</ref><ref>{{cite web|url=http://www.osnews.com/story/24572/Apple_Ditches_SAMBA_in_Favour_of_Homegrown_Replacement|title=Apple Ditches SAMBA in Favour of Homegrown Replacement|author=Thom Holwerda|date=March 26, 2011|access-date=January 12, 2014|archive-url=https://web.archive.org/web/20131102235327/http://www.osnews.com/story/24572/Apple_Ditches_SAMBA_in_Favour_of_Homegrown_Replacement|archive-date=November 2, 2013|url-status=live}}</ref>

The [[Linux kernel]]'s CIFS client file system has SMB2 support since version 3.7.<ref>{{cite web|url=https://kernelnewbies.org/Linux_3.7#head-7c9c911e4c41bcbc635cd8fa561278c833844bc2|title=Linux 3.7 - Linux Kernel Newbies|access-date=September 4, 2016|archive-url=https://web.archive.org/web/20160911130335/https://kernelnewbies.org/Linux_3.7#head-7c9c911e4c41bcbc635cd8fa561278c833844bc2|archive-date=September 11, 2016|url-status=live}}</ref>

=== SMB 2.1 ===
SMB 2.1, introduced with Windows 7 and Server 2008 R2, introduced minor performance enhancements with a new opportunistic locking mechanism.<ref>{{cite web|url=http://www.microsoft.com/downloads/details.aspx?displaylang=en&FamilyID=d8541618-5c63-4c4d-a0fd-d942cd3d2ec6|publisher=[[Microsoft]]|access-date=November 2, 2009|date=October 21, 2009|title=Implementing an End-User Data Centralization Solution|pages=10–11|archive-url=https://web.archive.org/web/20100906141857/http://www.microsoft.com/downloads/details.aspx?displaylang=en&FamilyID=d8541618-5c63-4c4d-a0fd-d942cd3d2ec6|archive-date=September 6, 2010|url-status=live}}</ref>

=== SMB 3.0 ===
SMB 3.0 (previously named SMB 2.2)<ref name="smb3">{{cite web|url=https://cloudblogs.microsoft.com/windowsserver/2012/04/19/smb-2-2-is-now-smb-3-0/|work=Windows Server Blog|title=SMB 2.2 is now SMB 3.0|author=Jeffrey Snover|date=April 19, 2012|access-date=July 6, 2020|archive-date=July 8, 2020|archive-url=https://web.archive.org/web/20200708211728/https://cloudblogs.microsoft.com/windowsserver/2012/04/19/smb-2-2-is-now-smb-3-0/|url-status=live}}</ref> was introduced with [[Windows 8]]<ref name="smb3"/> and [[Windows Server 2012]].<ref name="smb3"/> It brought several significant changes that are intended to add functionality and improve SMB2 performance,<ref>{{cite web | url=http://www.chelsio.com/chelsio-to-demonstrate-40g-smb-direct-rdma-over-ethernet-for-windows-server-2012/ | title=40G SMB Direct | author=Chelsio Communications | date=2 April 2013 | access-date=June 18, 2013 | archive-url=https://web.archive.org/web/20130907065805/http://www.chelsio.com/chelsio-to-demonstrate-40g-smb-direct-rdma-over-ethernet-for-windows-server-2012/ | archive-date=September 7, 2013 | url-status=live }}</ref> notably in virtualized [[data center]]s:
* the SMB Direct Protocol (SMB over [[remote direct memory access]] [RDMA])
* SMB Multichannel (multiple connections per SMB session),<ref>{{cite web | url=https://www.eiseverywhere.com/file_uploads/b4f7436c4bc86fe545abe9fc042d4a7f_JoseBarreto_SMB3_Remote_File_Protocol_revision.pdf | title=SNIA Tutorial on the SMB Protocol | author=Jose Barreto | date=October 19, 2012 | access-date=November 28, 2012 | publisher=[[Storage Networking Industry Association]] | archive-url=https://web.archive.org/web/20130603133014/https://www.eiseverywhere.com/file_uploads/b4f7436c4bc86fe545abe9fc042d4a7f_JoseBarreto_SMB3_Remote_File_Protocol_revision.pdf | archive-date=June 3, 2013 | url-status=live }}</ref><ref>{{ cite web | url=http://www.snia.org/sites/default/files2/SDC2011/presentations/keynote/ThomasPfenning_The_Future_of_File_Protocols-final.pdf | title=The Future of File Protocols: SMB 2.2 in the Datacenter |archive-url=https://web.archive.org/web/20120720020805/http://www.snia.org/sites/default/files2/SDC2011/presentations/keynote/ThomasPfenning_The_Future_of_File_Protocols-final.pdf |archive-date=2012-07-20 | author=Thomas Pfenning }}</ref>
* SMB Transparent Failover<ref>{{cite web | url = https://blogs.technet.microsoft.com/clausjor/2012/06/07/smb-transparent-failover-making-file-shares-continuously-available/ | title = SMB Transparent Failover – making file shares continuously available | date = 2012-06-07 | first = Claus | last = Joergensen | work = Microsoft TechNet | access-date = February 1, 2017 | archive-url = https://web.archive.org/web/20190111144942/https://blogs.technet.microsoft.com/clausjor/2012/06/07/smb-transparent-failover-making-file-shares-continuously-available/ | archive-date = January 11, 2019 | url-status = live }}</ref><ref>{{cite web | url = http://windowsitpro.com/windows-server-2012/new-ways-enable-high-availability-file-shares | title = New Ways to Enable High Availability for File Shares | date = 2012-08-21 | first = John | last = Savill | work = Windows IT Pro | access-date = February 1, 2017 | archive-url = https://web.archive.org/web/20161127102639/http://windowsitpro.com/windows-server-2012/new-ways-enable-high-availability-file-shares | archive-date = November 27, 2016 | url-status = live }}</ref>

It also introduces several security enhancements, such as [[end-to-end encryption]] and a new [[Advanced Encryption Standard|AES]] based signing algorithm.<ref>{{cite web | url=https://technet.microsoft.com/en-us/library/dn551363.aspx | title=SMB Security Enhancements | publisher=Microsoft Technet | date=January 15, 2014 | access-date=June 18, 2014 | archive-url=https://web.archive.org/web/20141009101031/http://technet.microsoft.com/en-us/library/dn551363.aspx | archive-date=October 9, 2014 | url-status=live }}</ref><ref>{{cite web|url=https://blogs.technet.microsoft.com/josebda/2013/05/05/updated-links-on-windows-server-2012-file-server-and-smb-3-0/|title=Updated Links on Windows Server 2012 File Server and SMB 3.0|author=Jose Barreto|date=May 5, 2013|publisher=[[Microsoft TechNet]] Server & Management Blogs|access-date=August 14, 2016|archive-url=https://web.archive.org/web/20160803070533/https://blogs.technet.microsoft.com/josebda/2013/05/05/updated-links-on-windows-server-2012-file-server-and-smb-3-0/|archive-date=August 3, 2016|url-status=live}}</ref>

=== SMB 3.0.2 ===
SMB 3.0.2 (known as 3.02 at the time) was introduced with Windows 8.1 and Windows Server 2012 R2;<ref>{{cite web|url=https://blogs.technet.microsoft.com/josebda/2014/07/07/updated-links-on-windows-server-2012-r2-file-server-and-smb-3-02/|title=Updated Links on Windows Server 2012 R2 File Server and SMB 3.02|author=Jose Barreto|date=July 7, 2014|publisher=[[Microsoft TechNet]] Server & Management Blogs|access-date=August 14, 2016|archive-url=https://web.archive.org/web/20160826110750/https://blogs.technet.microsoft.com/josebda/2014/07/07/updated-links-on-windows-server-2012-r2-file-server-and-smb-3-02/|archive-date=August 26, 2016|url-status=live}}</ref><ref>{{cite web|url=https://blogs.technet.microsoft.com/josebda/2013/12/12/storage-developer-conference-sdc-2013-slides-now-publicly-available-here-are-the-links-to-microsoft-slides/|title=Storage Developer Conference – SDC 2013 slides now publicly available. Here are the links to Microsoft slides…|author=Jose Barreto|date=December 12, 2013|publisher=[[Microsoft TechNet]] Server & Management Blogs|access-date=August 14, 2016|archive-url=https://web.archive.org/web/20160826113828/https://blogs.technet.microsoft.com/josebda/2013/12/12/storage-developer-conference-sdc-2013-slides-now-publicly-available-here-are-the-links-to-microsoft-slides/|archive-date=August 26, 2016|url-status=live}}</ref> in those and later releases, the earlier SMB version 1 can be optionally disabled to increase security.<ref>{{cite web|url=http://www.windowsnetworking.com/articles-tutorials/windows-server-2012/improvements-smb-30-and-302-protocol-updates.html|title=WindowsNetworking.com: Improvements in the SMB 3.0 and 3.02 Protocol Updates|author=Eric Geier|date=December 5, 2013|website=WindowsNetworking.com|access-date=April 6, 2015|archive-url=https://web.archive.org/web/20150409010758/http://www.windowsnetworking.com/articles-tutorials/windows-server-2012/improvements-smb-30-and-302-protocol-updates.html|archive-date=April 9, 2015|url-status=live}}</ref><ref name="barreto-smb3-links-ws2012r2">{{cite web|url=https://blogs.technet.microsoft.com/josebda/2015/04/30/smb3-networking-links-for-windows-server-2012-r2/|title=SMB3 Networking Links for Windows Server 2012 R2|author=Jose Barreto|date=April 30, 2015|publisher=[[Microsoft TechNet]] Server & Management Blogs|access-date=August 14, 2016|archive-url=https://web.archive.org/web/20160826115342/https://blogs.technet.microsoft.com/josebda/2015/04/30/smb3-networking-links-for-windows-server-2012-r2/|archive-date=August 26, 2016|url-status=live}}</ref>

=== SMB 3.1.1 ===
SMB 3.1.1 was introduced with [[Windows 10]] and [[Windows Server 2016]].<ref>{{cite web|url=https://blogs.technet.microsoft.com/josebda/2015/05/05/whats-new-in-smb-3-1-1-in-the-windows-server-2016-technical-preview-2/|title=What's new in SMB 3.1.1 in the Windows Server 2016 Technical Preview 2|author=Jose Barreto|date=May 5, 2015|publisher=[[Microsoft TechNet]] Server & Management Blogs|access-date=August 14, 2016|archive-url=https://web.archive.org/web/20161008054848/https://blogs.technet.microsoft.com/josebda/2015/05/05/whats-new-in-smb-3-1-1-in-the-windows-server-2016-technical-preview-2/|archive-date=October 8, 2016|url-status=live}}</ref> This version supports [[Advanced Encryption Standard|AES-128]] [[Galois/Counter Mode|GCM]] encryption in addition to AES-128 [[CCM mode|CCM]] encryption added in SMB3, and implements pre-authentication integrity check using [[SHA-512]] hash. SMB 3.1.1 also makes secure negotiation mandatory when connecting to clients using SMB versions that support it.<ref>{{Cite web|url=https://learn.microsoft.com/en-us/windows-server/storage/file-server/smb-security#smb-encryption|title=SMB security enhancements|publisher=Microsoft Learn|access-date=2023-04-10|archive-date=2023-04-10|archive-url=https://web.archive.org/web/20230410045614/https://learn.microsoft.com/en-us/windows-server/storage/file-server/smb-security#smb-encryption|url-status=live}}</ref>