Hardware-based encryption: Difference between revisions

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{{Short description|Use of computer hardware to assist software in the process of data encryption}}

{{Infobox industrial process

|type=[[Cryptography]]

|sector=[[Computing]]

|technologies=[[Cryptographic Hashhash Functionfunction]], [[Encryption]]

|image = IBM4758 outside1.JPG

|caption = The [[IBM 4758]] Cryptographic Module

}}

Hardware-based encryption is the use of [[Computer Hardware]] to assist software, or sometimes replace software, in the process of data [[encryption]]. Typically, this is implemented as part of the [[CPU|processor]]'s instruction set. For example, the [[Advanced Encryption Standard|AES]] encryption algorithm (a modern [[cipher]]) can be implemented using the [[AES instruction set]] on the ubiquitous [[x86]] architecture.<ref name="Intel AES Instructions">{{cite book|title=Intel® 64 and IA-32 Architectures Software Developer’s Manual|date={{date|December 2017}}|url=https://software.intel.com/sites/default/files/managed/39/c5/325462-sdm-vol-1-2abcd-3abcd.pdf|publisher=Intel|pages=303-309,410}}</ref> Such instructions also exist on the [[ARM architecture]].<ref name="cortex cryptography">{{cite book|title=ARM® Cortex®-A57 MPCore Processor Cryptography Extension|date={{date|2017-12-17}}|publisher=ARM Holdings|url=http://infocenter.arm.com/help/topic/com.arm.doc.ddi0514g/DDI0514G_cortex_a57_mpcore_cryptography_trm.pdf}}</ref> However, more unusual systems exist where the cryptography module is separate from the central processor, instead being implemented as a [[coprocessor]], in particular a [[secure cryptoprocessor]], of which an example is the [[IBM 4764]]<ref name="IBM 4764">{{cite web|url=https://www.ibm.com/support/knowledgecenter/ssw_ibm_i_61/rzajc/rzajcco4758.htm|title=4764 Cryptographic Coprocessor|publisher=IBM|access-date={{date|2018-01-20}}}}</ref>. Hardware implementations can be faster and less prone to exploitation than traditional software implementations, and furthermore can be protected against tampering.<ref name="performance">{{cite web|title=AES-NI Performance Analyzed|url=http://www.tomshardware.com/reviews/clarkdale-aes-ni-encryption,2538.html|publisher=Tom's Hardware|year=2010|author=P. Schmid and A. Roos |accessdate={{date|2018-01-20}}}}</ref> However, hardware implementations use additional space on the processor die, and any security vulnerability (such as [[Spectre (security vulnerability)|Spectre]]) cannot be solved with a software update.<ref name="MeltdownSpectre">{{Cite web |author=Staff |url=https://spectreattack.com/ |title=Meltdown and Spectre |date=2018 |work=[[Graz University of Technology]] |access-date={{date|2018-01-20}} |dead-url=no |archive-url=https://web.archive.org/web/20180103221345/https://spectreattack.com/ |archive-date={{date|2018-01-03}}}}</ref>

'''Hardware-based encryption''' is the use of [[computer hardware]] to assist software, or sometimes replace software, in the process of data [[encryption]]. Typically, this is implemented as part of the [[CPU|processor]]'s [[Instruction set architecture|instruction set]]. For example, the [[Advanced Encryption Standard|AES]] encryption algorithm (a modern [[cipher]]) can be implemented using the [[AES instruction set]] on the ubiquitous [[x86 architecture]].<ref name="Intel AES Instructions" /> Such instructions also exist on the [[ARM architecture]].<ref name="cortex cryptography" /> However, more unusual systems exist where the cryptography module is separate from the central processor, instead being implemented as a [[coprocessor]], in particular a [[secure cryptoprocessor]] or [[cryptographic accelerator]], of which an example is the [[IBM 4758]], or its successor, the [[IBM 4764]].<ref name="IBM 4764" /> Hardware implementations can be faster and less prone to exploitation than traditional software implementations, and furthermore can be protected against tampering.<ref name="performance" />

== History ==

Hardware-basedPrior encryptionto arguablythe beganuse inof thecomputer 1987hardware, withcryptography thecould ABYSSbe (Aperformed Basicthrough Yorktownvarious Securitymechanical System)or project[[electro-mechanical]] means. An early example is the [[Scytale]] used by the [[Spartan]]s.<ref name="Kelly">{{citeCite webjournal|urllast=https://www.computer.org/csdl/proceedings/sp/1987/0771/00/07710038.pdfKelly|first=Thomas|title=ABYSS:The AMyth Trustedof Architecturethe for Software ProtectionSkytale|access-datejournal={{Cryptologia|date=July 1998|2018pages=244&ndash;260|doi=10.1080/0161-01-20}}119891886902|volume=22|issue=3}}</ref><ref name="buildingThe 4758">{{cite[[Enigma web|url=http://www.research.ibm.com/people/s/sailer/publications/2001/ibm4758.pdf|title=Buildingmachine]] was an electro-mechanical system cipher machine notably used by the IBMGermans 4758in Secure[[World CoprocessorWar II]].{{citation needed|access-date={{date|June 2018-01-20}}|publisher= After [[IBMWorld War II]]}}, purely electronic systems were developed. In 1987 the ABYSS (A Basic Yorktown Security System) project was initiated.<ref name="ABYSS" /><ref name="building 4758" /> The aim of this project was to protect against [[Softwaresoftware Piracypiracy]]. However, the application of computers to cryptography in general dates back to the 1940s and [[Bletchley Park]], where the [[Colossus computer]] was used to break the encryption used by German High Command during [[World War 2II]]. The use of computers to ''encrypt'', however, came later. In particular, until the development of the [[Intergratedintegrated Circuitcircuit]], of which the first was produced in 1960, computers were impractical for encryption, since, in comparison to the portable [[form factor (design)|form factor]] of the [[Enigma machine]],<ref>{{cite web|url=http://www.cryptomuseum.com/kits/enigma/support/files/case.pdf|publishername="Crypto Museum|title=Enigma-E" case|access-date={{date|2018-01-20}}}}</ref> Computers[[SIGSALY|computers of the era]] took the space of an entire building. It was only with the development of the [[Microcomputermicrocomputer]] that computer encryption became feasible, outside of niche applications. The development of the [[World Wide Web]] lead to the need for consumers to have access to encryption, as [[Onlineonline Shoppingshopping]] became prevalent.<ref name="consumers">{{cite web | url=http://ecommercenews.eu/consumers-online-shopping-expectations/ | title=Consumers and their online shopping expectations – Ecommerce News | date={{date|2015-2-20}}| accessdate={{date|2016-08-29}}}}</ref> The key concerns for consumers were security and speed.<ref name="consumers" /> This led to the eventual inclusion of the key algorithms into processors as a way of both increasing speed and security.<ref name="performance" />

== Implementations ==

=== In the [[Instructioninstruction Set]]set ===

==== [[x86]] ====

{{Main|AES instruction set|Intel SHA extensions}}

The [[X86]] [[Computer architecture|architecture]], as a [[Complex instruction set computer|CISC (Complex Instruction Set Computer)]] Architecture, typically implements complex [[algorithms]] in hardware.<ref name="Oxford" /> Cryptographic algorithms are no exception. The x86 architecture implements significant components of the [[Advanced Encryption Standard|AES (Advanced&nbsp;Encryption&nbsp;Standard)]] algorithm,<ref name="Intel AES Instructions" /> which can be used by the [[NSA]] for [[Top Secret]] information.<ref>{{cite web|urlname=http://csrc.nist.gov/groups/ST/toolkit/documents/aes/CNSS15FS.pdf |title=National Policy on the Use of the Advanced Encryption Standard (AES) to Protect"NIST National Security" Systems and National Security Information |author=Lynn Hathaway |date={{date|June 2003}}|format=PDF |access-date={{date|2011-02-15}}}}</ref> The architecture also includes support for the [[Secure Hash Algorithms|SHA]] Hashing Algorithms through the [[Intel SHA extensions]].<ref name="Intel AES Instructions" /> Whereas AES is a cipher, which is useful for encrypting documents, [[HashingHash function|hashing]] is used for verification, such as of passwords (see [[PBKDF2]]).

==== ARM ====

[[ARM processorsprocessor]]s can optionally support Security Extensions. Although ARM is a [[RISC|RISC (Reduced Instruction Set Computer)]] architecture, there are several optional extensions specified by [[ARM Holdings]].<ref name="cortex cryptography" /><ref name="openwrt">[http://wiki.openwrt.org/doc/hardware/cryptographic.hardware.accelerators Cryptographic Hardware Accelerators] on OpenWRT.org</ref>

=== As a coprocessor ===

* [[IBM 4758]] -– The predecessor to the [[IBM 4764]].<ref name="NIST approval" /> This includes its own specialised processor, [[Random-access memory|memory]] and a [[Random Number Generator]].<ref name="IBM 4758 datasheet" />

* [[IBM 4764]] - This is identical to theand [[IBM 4765]], identical except for the connection used.<ref name="NIST approval" /> The former uses [[PCI-X]], while the latter uses [[PCI-e]].<ref name="IBM 4764" /> Both are [[peripheral devices]] that plug into the [[motherboard]].

=== Proliferation ===

[[Advanced Micro Devices]] (AMD) processors are also x86 devices, and have supported the [[AES instruction set|AES instructions]] since the 2011 [[Bulldozer (microarchitecture)|Bulldozer]] processor iteration.<ref name="Arecibo Bulldozer" />

Due to the existence of encryption instructions on modern processors provided by both [[Intel]] and AMD, the instructions are present on most modern computers.<ref name="Haifa" /> They also exist on many tablets and smartphones due to their implementation in [[ARM architecture|ARM processors]].<ref name="Haifa" />

== Advantages ==

Implementing cryptography in hardware means that part of the processor is dedicated to the task. This can lead to a large increase in speed.<ref name="performance" /> In particular, modern processor architectures that support [[Pipelining (computing)|pipelining]] can often perform other instructions concurrently with the execution of the encryption instruction. Furthermore, hardware can have methods of protecting data from software. Consequently, even if the [[Operatingoperating Systemsystem]] is compromised, the data may still be secure (see [[Software Guard Extensions]]).<ref>{{cite web|url=https://software.intel.com/en-us/blogs/2013/09/26/protecting-application-secrets-with-intel-sgx |titlename="Intel SGX" for Dummies (Intel SGX Design Objectives) |work=intel.com |date=2013-09-26}}</ref>

== Disadvantages ==

If, however, the hardware implementation is compromised, major issues arise. Malicious software can retrieve the data from the (supposedly) secure hardware -– a large class of method used is the [[timing attack]].<ref name=":0BearSSL">{{Cite web|url=https://www.bearssl.org/constanttime.html|title=BearSSL – Constant-Time Crypto|website=www.bearssl.org|access-date=2017-01-10}}</ref> This is far more problematic to solve than a software bug, even within the Operating[[operating Systemsystem]]. [[Microsoft]] regularly deals with security issues through [[Windows Update]]. Similarly, regular security updates are released for [[Mac OS X]] and [[Linux]], as well as mobile Operatingoperating Systemssystems like [[iOS]], [[Android (operating system)|Android]], and [[Windows Phone]]. However, hardware is a different issue. Sometimes, the issue will be fixable through updates to the processor's [[microcode]] (a low level type of software). However, other issues may only be resolvable through replacing the hardware, or a workaround in the operating system which mitigates the performance benefit of the hardware implementation, such as in the [[Spectre (security vulnerability)|Spectre exploit]] exploit.<ref name="PCW-20180109" />{{cite web |author-last

=Hachman |author-first=MarkSee |titlealso=Microsoft tests show Spectre patches drag down performance on older PCs |url=https://www.pcworld.com/article/3245742/components-processors/microsoft-tests-show-spectre-patches-drag-down-performance-on-older-pcs.html |date=January 9, 2018 |work=[[PC World]] |access-date=2018-01-09}}</ref>

* [[Disk encryption hardware]]

* [[Hardware-based full disk encryption]]

* [[Hardware security module]]

==References==

{{Reflist|30em}}|refs=

<ref name="Intel AES Instructions">{{cite book|title=Intel® 64 and IA-32 Architectures Software Developer's Manual|date=December 2017|url=https://software.intel.com/sites/default/files/managed/39/c5/325462-sdm-vol-1-2abcd-3abcd.pdf|publisher=Intel|pages=303–309, 410}}</ref>

<ref name="cortex cryptography">{{cite book|title=ARM® Cortex®-A57 MPCore Processor Cryptography Extension|date=17 December 2017|publisher=ARM Holdings|url=http://infocenter.arm.com/help/topic/com.arm.doc.ddi0514g/DDI0514G_cortex_a57_mpcore_cryptography_trm.pdf|url-status=live|archive-url=https://web.archive.org/web/20161213102201/http://infocenter.arm.com/help/topic/com.arm.doc.ddi0514g/DDI0514G_cortex_a57_mpcore_cryptography_trm.pdf|archive-date=2016-12-13}}</ref>

<ref name="IBM 4764">{{cite web|url=https://www.ibm.com/support/knowledgecenter/ssw_ibm_i_61/rzajc/rzajcco4758.htm|title=4764 Cryptographic Coprocessor|publisher=IBM|access-date=20 January 2018|url-status=live|archive-url=https://web.archive.org/web/20180121000028/https://www.ibm.com/support/knowledgecenter/ssw_ibm_i_61/rzajc/rzajcco4758.htm|archive-date=2018-01-21}}</ref>

<ref name="performance">{{cite web|title=AES-NI Performance Analyzed|url=http://www.tomshardware.com/reviews/clarkdale-aes-ni-encryption,2538.html|publisher=Tom's Hardware|year=2010|author=P. Schmid and A. Roos |access-date=20 January 2018}}</ref>

<ref name="ABYSS">{{cite web|url=https://www.computer.org/csdl/proceedings/sp/1987/0771/00/07710038.pdf|title=ABYSS: A Trusted Architecture for Software Protection|access-date=20 January 2018|url-status=live|archive-url=https://web.archive.org/web/20180121071623/https://www.computer.org/csdl/proceedings/sp/1987/0771/00/07710038.pdf|archive-date=2018-01-21}}</ref>

<ref name="building 4758">{{cite web|url=http://www.research.ibm.com/people/s/sailer/publications/2001/ibm4758.pdf|title=Building the IBM 4758 Secure Coprocessor|access-date=20 January 2018|publisher=[[IBM]]|url-status=live|archive-url=https://web.archive.org/web/20170808032012/http://www.research.ibm.com/people/s/sailer/publications/2001/ibm4758.pdf|archive-date=2017-08-08}}</ref>

<ref name="Crypto Enigma">{{cite web|url=http://www.cryptomuseum.com/kits/enigma/support/files/case.pdf|publisher=Crypto Museum|title=Enigma-E case|access-date=20 January 2018|url-status=live|archive-url=https://web.archive.org/web/20161105032157/http://www.cryptomuseum.com/kits/enigma/support/files/case.pdf|archive-date=2016-11-05}}</ref>

<ref name="consumers">{{cite web | url=http://ecommercenews.eu/consumers-online-shopping-expectations/ | title=Consumers and their online shopping expectations – Ecommerce News | date=20 February 2015 | access-date=29 August 2016 | url-status=live | archive-url=https://web.archive.org/web/20160930235730/http://ecommercenews.eu/consumers-online-shopping-expectations/ | archive-date=2016-09-30 }}</ref>

<ref name="Oxford">{{cite web|url=https://www.cs.ox.ac.uk/teaching/materials17-18/ca/lecture03.pdf|title=x86-64 Instruction Set|publisher=[[University of Oxford]]|pages=1|date=18 April 2017|access-date=24 January 2018}}</ref>

<ref name="NIST National Security">{{cite web |url=http://csrc.nist.gov/groups/ST/toolkit/documents/aes/CNSS15FS.pdf |title=National Policy on the Use of the Advanced Encryption Standard (AES) to Protect National Security Systems and National Security Information |author=Lynn Hathaway |date=June 2003 |access-date=15 February 2011 |url-status=live |archive-url=https://web.archive.org/web/20101106122007/http://csrc.nist.gov/groups/ST/toolkit/documents/aes/CNSS15FS.pdf |archive-date=2010-11-06 }}</ref>

<ref name="IBM 4758 datasheet">{{cite web|url=ftp://www6.software.ibm.com/software/cryptocards/G221-9091-04.pdf|title=IBM 4758 Models 2 and 23 PCI Cryptographic Coprocessor|date=May 2004|access-date=24 January 2018|archive-url=https://web.archive.org/web/20170705054058/ftp://www6.software.ibm.com/software/cryptocards/G221-9091-04.pdf|archive-date=2017-07-05|url-status=dead|publisher=[[IBM]]}}</ref>

<ref name="openwrt">{{cite web|url=http://wiki.openwrt.org/doc/hardware/cryptographic.hardware.accelerators|title=Cryptographic Hardware Accelerators|publisher=OpenWRT.org|date=17 May 2016|access-date=25 January 2018|url-status=live|archive-url=https://web.archive.org/web/20180121000023/http://wiki.openwrt.org/doc/hardware/cryptographic.hardware.accelerators|archive-date=2018-01-21}}</ref>

<ref name="NIST approval">{{cite web|url=https://csrc.nist.gov/csrc/media/projects/cryptographic-module-validation-program/documents/security-policies/140sp1505.pdf|date=10 December 2012|access-date=20 January 2018|title=IBM 4765 Cryptographic Coprocessor Security Module|publisher=[[National Institute of Standards and Technology]]|url-status=live|archive-url=https://web.archive.org/web/20180125015153/https://csrc.nist.gov/csrc/media/projects/cryptographic-module-validation-program/documents/security-policies/140sp1505.pdf|archive-date=2018-01-25}}</ref>

<ref name="Arecibo Bulldozer">{{cite web|url=https://www.naic.edu/~phil/software/amd/New-Bulldozer-and-Piledriver-Instructions-1.pdf|date=October 2012|access-date=25 January 2018|title=New "Bulldozer" and "Piledriver" Instructions|publisher=[[Arecibo Observatory]]|author=Brent Hollingsworth ([[Advanced Micro Devices|AMD]])|url-status=live|archive-url=https://web.archive.org/web/20180209120423/https://www.naic.edu/~phil/software/amd/New-Bulldozer-and-Piledriver-Instructions-1.pdf|archive-date=2018-02-09}}</ref>

<ref name="Haifa">{{cite web|url=https://eprint.iacr.org/2016/122.pdf|title=Simpira v2: A Family of Efficient Permutations Using the AES Round Function|date=9 November 2016|access-date=25 January 2018|author=Shay Gueron ([[University of Haifa]] & [[Intel]]) and Nicky Mouha ([[KU Leuven]] & [[NIST]])|url-status=live|archive-url=https://web.archive.org/web/20170716025858/https://eprint.iacr.org/2016/122.pdf|archive-date=2017-07-16}}</ref>

<ref name="Intel SGX">{{cite web |url=https://software.intel.com/en-us/blogs/2013/09/26/protecting-application-secrets-with-intel-sgx |title=Intel SGX for Dummies (Intel SGX Design Objectives) |work=intel.com |date=2013-09-26 |url-status=live |archive-url=https://web.archive.org/web/20140429161139/https://software.intel.com/en-us/blogs/2013/09/26/protecting-application-secrets-with-intel-sgx |archive-date=2014-04-29 }}</ref>

<ref name="BearSSL">{{Cite web|url=https://www.bearssl.org/constanttime.html|title=BearSSL – Constant-Time Crypto|website=www.bearssl.org|access-date=2017-01-10|url-status=live|archive-url=https://web.archive.org/web/20170111003347/https://www.bearssl.org/constanttime.html|archive-date=2017-01-11}}</ref>

<ref name="PCW-20180109">{{cite web |author-last=Hachman |author-first=Mark |title=Microsoft tests show Spectre patches drag down performance on older PCs |url=https://www.pcworld.com/article/3245742/components-processors/microsoft-tests-show-spectre-patches-drag-down-performance-on-older-pcs.html |date=January 9, 2018 |work=[[PC World]] |access-date=2018-01-09 |url-status=live |archive-url=https://web.archive.org/web/20180209120423/https://www.pcworld.com/article/3245742/components-processors/microsoft-tests-show-spectre-patches-drag-down-performance-on-older-pcs.html |archive-date=February 9, 2018 }}</ref>

}}

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