Journal Editorial Board Editor-in-ChiefProf. Thomas Byeongnam YOON, PhD.
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ICACT Transactions on the Advanced Communications Technology (TACT) Editors
Prof. Jun-Chul Chun, Kyonggi University, Korea
Dr. JongWon Kim, GIST (Gwangju Institute of Science & Technology), Korea
Dr. Xi Chen, State Grid Corparation of China, China
Prof. Arash Dana, Islamic Azad university , Central Tehran Branch, Iran
Dr. Pasquale Pace, University of Calabria - DEIS - Italy, Italy
Dr. Mitch Haspel, Stochastikos Solutions R&D, Israel
Prof. Shintaro Uno, Aichi University of Technology, Japan
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Copyright ⓒ 2019 GiRI (Global IT Research Institute)Dr. Youssef SAID, Tunisie Telecom, Tunisia
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Copyright ⓒ 2019 GiRI (Global IT Research Institute)Dr. Il Kwon Cho, National Information Society Agency, Korea
Prof. Jiann-Liang Chen, National Taiwan University of Science and Technology, Taiwan
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Prof. Dae-Ki Kang, Dongseo University, Korea
Dr. Yong-Sik Choi, Research Institute, IDLE co., ltd, Korea
Dr. Xuena Peng, Northeastern University, China
Dr. Ming-Shen Jian, National Formosa University, Taiwan
Dr. Soobin Lee, KAIST Institute for IT Convergence, Korea
Prof. Yongpan Liu, Tsinghua University, China
Prof. Chih-Lin HU, National Central University, Taiwan
Prof. Chen-Shie Ho, Oriental Institute of Technology, Taiwan
Dr. Hyoung-Jun Kim, ETRI, Korea
Prof. Bernard Cousin, IRISA/Universite de Rennes 1, France
Prof. Eun-young Lee, Dongduk Woman s University, Korea
Dr. Porkumaran K, NGP institute of technology India, India
Dr. Feng CHENG, Hasso Plattner Institute at University of Potsdam, Germany
Prof. El-Sayed M. El-Alfy, King Fahd University of Petroleum and Minerals, Saudi Arabia
Prof. Lin You, Hangzhou Dianzi Univ, China
Mr. Nicolai Kuntze, Fraunhofer Institute for Secure Information Technology, Germany
Dr. Min-Hong Yun, ETRI, Korea
Dr. Seong Joon Lee, Korea Electrotechnology Research Institute, korea
Dr. Kwihoon Kim, ETRI, Korea
Dr. Jin Woo HONG, Electronics and Telecommunications Research Inst., Korea
Dr. Heeseok Choi, KISTI(Korea Institute of Science and Technology Information), korea
Dr. Somkiat Kitjongthawonkul, Australian Catholic University, St Patrick's Campus, Australia
Dr. Dae Won Kim, ETRI, Korea
Dr. Ho-Jin CHOI, KAIST(Univ), Korea
Dr. Su-Cheng HAW, Multimedia University, Faculty of Information Technology, Malaysia
Dr. Myoung-Jin Kim, Soongsil University, Korea
Dr. Gyu Myoung Lee, Institut Mines-Telecom, Telecom SudParis, France
Dr. Dongkyun Kim, KISTI(Korea Institute of Science and Technology Information), Korea
Prof. Yoonhee Kim, Sookmyung Women s University, Korea
Prof. Li-Der Chou, National Central University, Taiwan
Prof. Young Woong Ko, Hallym University, Korea
Prof. Dimiter G. Velev, UNWE(University of National and World Economy), Bulgaria
Dr. Tadasuke Minagawa, Meiji University, Japan
Prof. Jun-Kyun Choi, KAIST (Univ.), Korea
Dr. Brownson ObaridoaObele, Hyundai Mobis Multimedia R&D Lab , Korea
Prof. Anisha Lal, VIT university, India
Dr. kyeong kang, University of technology sydney, faculty of engineering and IT , Australia
Prof. Chwen-Yea Lin, Tatung Institute of Commerce and Technology, Taiwan
Dr. Ting Peng, Chang'an University, China
Prof. ChaeSoo Kim, Donga University in Korea, Korea
Prof. kirankumar M. joshi, m.s.uni.of baroda, India
Dr. Chin-Feng Lin, National Taiwan Ocean University, Taiwan
Dr. Chang-shin Chung, TTA(Telecommunications Technology Association), Korea

Copyright ⓒ 2019 GiRI (Global IT Research Institute)Dr. Che-Sheng Chiu, Chunghwa Telecom Laboratories, Taiwan
Dr. Chirawat Kotchasarn, RMUTT, Thailand
Dr. Fateme Khalili, K.N.Toosi. University of Technology, IranDr. Izzeldin Ibrahim Mohamed Abdelaziz, Universiti Teknologi Malaysia , Malaysia
Dr. Kamrul Hasan Talukder, Khulna University, Bangladesh
Prof. HwaSung Kim, Kwangwoon University, Korea
Prof. Jongsub Moon, CIST, Korea University, Korea
Prof. Juinn-Horng Deng, Yuan Ze University, Taiwan
Dr. Yen-Wen Lin, National Taichung University, Taiwan
Prof. Junhui Zhao, Beijing Jiaotong University, China
Dr. JaeGwan Kim, SamsungThales co, Korea
Prof. Davar PISHVA, Ph.D., Asia Pacific University, Japan
Ms. Hela Mliki, National School of Engineers of Sfax, Tunisia
Prof. Amirmansour Nabavinejad, Ph.D., Sepahan Institute of Higher Education, Iran

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Copyright ⓒ 2019 GiRI (Global IT Research Institute)Journal Procedure
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Copyright ⓒ 2019 GiRI (Global IT Research Institute)Journal Submission Guide
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ICACT Transactions on Advanced Communications Technology (TACT) Vol. 8, Issue 5, September 2019

Volume. 8 Issue. 5

6J

1 Comprehending Taiwan ATM Heist: From Cyber-attack Phases to Investigation Processes

1231

Da-Yu KAO
Department of Information Management, Central Police University, Taoyuan 333, Taiwan

2 A High-Performance Parallel Hardware Architecture of SHA-256 Hash in ASIC

1242

Ruizhen Wu*, Xiaoyong Zhang**, Mingming Wang*, Lin Wang**Inspur Electronic Information Industry Co.,Ltd, Xi’an Shaanxi Province China**Biren Technology Ltd, Shanghai China

Copyright ⓒ 2019 GiRI (Global IT Research Institute)

ICACT Transactions on Advanced Communications Technology (TACT) Vol. 8, Issue 5, September 2019

1231

Comprehending Taiwan ATM Heist: From
Cyber-attack Phases to Investigation Processes
Da-Yu KAO
Department of Information Management, Central Police University, Taoyuan 333, Taiwan
dayukao@gmail.com

Abstract—Cybercriminals increasingly use sophisticated tools
and advanced methods to attack bank systems. Cyber black
markets for hacking tools or services are gaining widespreadattention as more advanced persistent threat attacks are relevant
to such markets. The recent cyber-attacks on banks or financial
institutions have increased the technical expertise of
cybercriminals. This study reviews ATM threats and highlights
the cybercrime investigation of ATM heist. An incident
investigation strategy from ISO/IEC 27043:2015 is proposed toembed cyber-attack phases and detect ATM heist. It demonstrates
how this strategy can provide investigators with exceptional
abilities to interpret evidence. By integrating an effective
cybercrime investigation strategy, investigators can minimize thecost of collecting evidence in a forensically sound manner.

Keyword—Cybercrime, ATM Threats, Bank Malware,
Criminal Group, ISO/IEC 27043: 2015, Cybercrime
Investigation, Malware Family
I. INTRODUCTION
A. Cybercrime Threats on Sophisticated ICT environment
The Internet has become an integral part of our society, and it
enriches our lives in countless ways. Information andcommunications technologies (ICTs) are the integration of
telecommunications, computers, and software, which enable
users to access information. As the computer systems of the new
ICT environment get more sophisticated than before, so do thecriminals. ICTs have facilitated not only the methods in which
crimes are committed but also the methods in which criminals
interact in committing them.
1) Exploitable Vulnerabilities to Computer System
Zero-day vulnerabilities are exploitable weaknesses that asoftware vendor is not aware of and for which no patch has been———————————————————————
Manuscript received Jan. 1, 2019. This work was a follow-up of the invitedjournal to the accepted & presented paper of the 21st Conference on Advanced
Communication Technology (ICACT2019), and this research was partiallysponsored by the Executive Yuan of the Republic of China under the Grants
Forward-looking
Infrastructure
Development
Program(Digital
Infrastructure-Information Security Project-109).
Da-Yu Kao is with the Department of Information Management, Central
Police University, Taoyuan 333, Taiwan (Corresponding Author phone:+886-3-328-2321; fax: +886-3-328-5189; e-mail: dayukao@gmail.com).

created. However, half-days are also prevalent in the black
market where the software creator may know of the weaknesses.
A patch may be available, but few users are aware of andimplementing those patches [18]. That is where the danger lies.
People are the greatest threat to a computer system [8]. More
exceptional care has to be paid to the individuals' authorizationto access sensitive data in the computer system since this can
reduce the number of attack incidents.
2) Increasing Expertise of Cybercriminals
The Internet has come to represent both attractive andavailable for finding victims. The data breach of hacking
activities becomes prevalent. The sophistication of
cybercriminals and their advantageous positions as attackers
will target the transactions for a data breach, and innovate inways to infiltrate computer systems [12].
3) Undetected Cybercrimes on Malware Attacks
Cyberspace consists of interrelated and interdependent ICT
devices. That includes the Internet, telecommunications
networks, and computer systems [4]. As ICT continues tochange and evolve, some cybercrimes remain undetected.
Cybercriminals increasingly use sophisticated tools andadvanced methods to distribute a wide range of malicious
attacks [6]. Cybercrimes require the advanced hacking
capability to target financial services, and the global economy
requires a proactive and coordinated response.
B. Financial Technology
Financial Technology (FinTech) refers to the use of softwareand digital platforms to deliver money exchange services to
consumers and make it easier than ever to make transactions
between two entities [21]. While much cybercrime is committed
by individuals acting alone, a significant amount of criminalgroups have tended to vary significantly in their criminal
activities. Cybercrimes are developing exponentially andthreating our FinTech. To fight against the unlimited growth ofAutomated Teller Machine (ATM) security threats, a soundknowledge of the problem and perpetrators can contribute topreventing cybercrimes.
1) Advantagesa) The Traditional Need for Strict Security Controls
Banks use many electronic systems for the operation of their

Copyright ⓒ 2019 GiRI (Global IT Research Institute)

ICACT Transactions on Advanced Communications Technology (TACT) Vol. 8, Issue 5, September 2019

economic environment. Traditionally, they use strict security
controls overall operational and transaction-related procedures.
In terms of segregation of duties, all systems administrationmust have dual login controls, rare network protocols, andmultiple serial firewalls for internal banking communications[3]. However, banks generally choose an open system due tofriendly user-interface, convenient process, or insufficientbudget. That raises severe concerns on ATM protection.
Several measures can be adopted by banks to detect, prevent,and minimize the cybercrime damage on the Internet.
b) Online ATMs for Convenient Payment Activities
Once computers or ATMs connect to the insecure Internet, no
one can guarantee their security. Online ATMs have gained
increasing popularity all over the world, as they provide
convenience to the public in managing their banking accounts
and payment activities [21]. The vulnerability of a complicated,fragmented ATM system relies on many providers to getcustomers to cash on demand. Due to the growth of FinTech,some ATM services have offered convenient payment solutions
to facilitate online internal examination.
2) Disadvantagesa) The Lack of Cybersecurity Awareness
Exploits take advantage of weaknesses or vulnerabilities insoftware. A vulnerability run malicious code onto compromised
computers. Malware can further infect other internal computers
without users’ knowledge [14]. Financial ATMs tointernet-connected industrials should not be built using
commercial operating systems for safety concerns. The lack of
cybersecurity awareness may enhance the vulnerability of
individuals and organizations. The threat of cybercrime
impedes the development of information technology. It could
contribute to the weakening of a nation’s economic security.
b) Unauthorized Access of Internal ATM Details
How can the criminal group obtain the internal ATM
information? Internal IP Address, computer name, and devicename should be challenging to match them. As far as ICT
governance is concerned, this kind of data is limited to internal
vital persons. The main threat arising is the possibility ofunauthorized access and use of bank card/ATM information bya fraudster [3]. Once malware is in place, buyers can rent themto deliver a variety of attacks. Active crime groups haverecognized the benefits of the Internet [21]. A bank systemshould have the boundary of a closed system for safety concerns[10]. A closed system has no external interactions and is an
isolated system that exchanges neither matter nor information
with its environment. No interactions can take the form of
information or material transfers into or out of the systemboundary.
3) Proper Security Measures
Banks may implement several organized policies to protect
against computer security threats. Moreover, banks need toprovide information security training to staff, increase theirawareness of the Internet dangers, and create effective practices

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to prevent its happening [22]. The following security measuresfor banks are recommended both to the cashpoints and theenvironment they are placed in, with sufficient lighting andcameras monitoring all activity [14].
 Review the physical security of all ATMs
 Consider investing in quality security solutions.
 Replace all locks and master keys on the upper hood of theATMs Ditch the defaults provided by the manufacturer.
 Install an alarm and ensure it is in good working order.
 Change the default BIOS password.
 Ensure the machines have up-to-date antivirus protection.
The literature reviews of organized cybercrime activities and
ATM threats are discussed in Section 2. Section 3 describes
specific questions and behavioral attributes in Taiwan ATM
Heist. An incident investigation strategy from ISO/IEC
27043:2015 is proposed to embed cyber-attack phases anddetect ATM heist in Section 4. Our conclusions are given in
Section 5.

II. LITERATURE REVIEWS
A. Organized Cybercrime Activities
Cybercrime has grown tremendously over the past decade as
public administration and private service gained a morefabulous online presence than before. The increasing risk ofcyber-attack is driven by continuously changing technology,
vulnerabilities, and advanced persistent threats. An ongoing
chronology of serious data breaches raises awareness aboutcybercrime issues [16]. A review is a necessary step in thecontinued growth of a multi-faceted lens on cyber-attack orinvestigation process. The cybercrime investigation disciplineintersects several fields, including computer science,criminology, and management. Cybercrime is a rapidly growing
phenomenon that requires a proactive and coordinatedresponse. The convenience for a user has become anotheradvantage for criminals [14]. The diversity of organizedcybercriminal exploits by state and non-state actors alike.
Criminal offenders or nation-states have entailed a diverse set oforganized activities. The following activities in Table I describe
some organized cybercrime activities in recent years [7, 8].
1) Cross-broader Hackers in Organized Crime Groups
Geographical boundaries have become trivial as
cyber-attacks are theoretically able to carry out from anywherein the world. The cyber exploitations can occur outside of thereach of local Law Enforcement Agencies (LEAs)[4]. The
Carberp malware source code was leaked and enhanced tocreate new threat products for sale to the underground fraudcommunity [14]. The future damage cannot be limited orcontrolled. The do-it-yourself malware toolkit sold by the grouphas been used to make unauthorized banking transactions.
2) Malware Black Market for Hackers
The arrests or takedowns in cyber-attacks often lead to public

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ICACT Transactions on Advanced Communications Technology (TACT) Vol. 8, Issue 5, September 2019

media coverage. Even if a group or individual gets taken down,
the vast majority of criminals do not be arrested [9]. The black
market of the organized group is on the increase and often
connected with crime groups or nation-states. The hackers inonline black markets or dark web grow smarter as they learn
from LEAs' investigative techniques. Cybercrime vendors soldaccess to a wide selection of malware or compromised zombies
from any country. Price tags for remote desktop-based accessrun no more than a few dollars. The criminal group could buy
access to bank employee computers that were alreadycompromised by massively distributed opportunistic malware[14]. The international reach of LEAs has some difficulties, andthe development of bank malware continued. Cybercriminals
would like to hide in any particular jurisdiction and avoid

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prosecution. They can make use of the lucrative malware black
market, raise funds for their activities, and gather intelligenceon possible targets [2].
3) The Need for Profiling Hackers
Investigating hackers is a time-consuming effort. The
Internet offers a degree of anonymity which affords organizedcrime groups the ability to recruit cross-broader hackers. The
hacker forums offer criminals a wide variety of malware for low
prices to assist them in criminal activities. The topic ofidentifying a practical framework of cybercrime investigation isa challenging one. No current set of profiling cybercriminals
exists. In this regard, the emergence of a useful cybercrime
investigation framework may rely on the experiences ofcybercrime investigation pioneers.

TABLE IORGANIZED CYBERCRIME ACTIVITIESYearGroup Name

1993~2001

DrinkOrDie (DoD)

1996~1998

The
Club

2003~

Anonymous

2006~2008

Dark Market

Actor

Wonderland
Non-state

PLA Unit 61398
2006~2010

Shady RAT
AuroraGhostNet

2007~2013

PRISM

2009~

Lazarus, Guardiansof Peace, or Whois
Team

Behavior TypeAn international groupcopyright pirates
A members-only groupof

A decentralized group of activist
and hacktivist entities.
A forum for the exchange ofstolen credit card and banking
details, and malicious software.
A large-scale program ofindustrial espionage
Anongoing
seriesofcyber-attacks
A series of cyber-attacks
A cyber espionage operation
A systematic harvesting programof digital information by the US
National Security Agency (NSA).

State
Compromised several banks andFintech companies.
A collaboration between the US
National Security Agency and its
Israeli counterpart, Unit 8200.
A malicious computer worm isbelieved to be a jointly built
American-Israeli cyberweapon.
Software engineers in Eastern
EuropeOperation Olympic
Games
2010~
Stuxnet2010~2012

Ukrainian Zeus
Non-state

2016~

MoneyTaker

Stole millions from U.S. &Russian Banks

Activity
Illegally reproduced and distributed software, games,
and movies over the Internet.
Exchanged illicit images of children.
Focus on website defacements, distributed denial ofservice attacks, and prominent symbols
Take advantage of the criminal opportunities
presented by the advent of electronic banking and theincreasing use of credit and debit cards.
Acquire a massive volume of data from a wide variety
of industries in English-speaking countries.
Hit at least 71 organizations
Aim at dozens of other organizations
Operate from commercial Internet accounts in China.
Capture and store a wide range of Internet data on thefollowing prominent IT companies: Microsoft,
Google, Yahoo!, Facebook, Pal Talk, YouTube,
Skype, AOL, and Apple.
Be famous for Operation Troy, Ten Days of Rain,
Sony breach, Operation Blockbuster, WannaCry,
cryptocurrency attacks
Disrupt the Iranian nuclear enrichment program.

Involve the clandestine insertion of a complex andsophisticated set of software into communications andcontrol systems at the Natanz nuclear facility.
Gain access to the computers of individuals employed
in a variety of small businesses, municipalities, andnon-government organizations in the United States.
Target Banks, financial institutions, and legal firms in
the United States, UK, and Russia.

Copyright ⓒ 2019 GiRI (Global IT Research Institute)

ICACT Transactions on Advanced Communications Technology (TACT) Vol. 8, Issue 5, September 2019

B. The Shadowy Criminal Group on ATM Threats
Cyber threats are still profitable for cybercrime groups andsponsored groups, who may attack bank systems for financial
profits or political reasons. Cyber risks and their follow-up
losses are becoming increasingly international across the world[7]. Cybercrime investigation of these cyber threats throughhacker tools, techniques, and procedures is critical for LEAs toprotect users and reduce fraud risk.
Some of the most notable malware families are ZeuS (itssuccessor Carberp) and Carberp (its successor Carbanak). The
criminal’s pragmatic approach starts a new chapter in the
cybercrime ecosystem [14]. In this era of increasing
cyber-attacks, many different malware families areprogrammed, especially for the majority of internet banking
fraud through malware. Bank heists are attracting large-scale
hackers with its unlimited borders, as cybercrime against
financial banks turns out to be an increasingly convenient way
to withdraw big money. This study focused on the Carberp
malware, and it showed there was a grey area between APT andmalware. There are a variety of shadowy criminal groups that
focus on banks and payment providers. The shadowy criminalgroup members began actively taking an interest in retailorganizations or bank payment systems. Hackers hacked up to$1 billion from more than 100 banks in 30 countries. ATM
hacking is becoming a new trend for an organized cybercrimegroup. There are a particular tutorial, tricks, and techniques
online about ATM devices hacking like Diebold, Defcon, orWincor Nixdorf [14, 19]. It is not easy to cheat an ATM
computer. If cybercrime targets financial services, it requires
advanced hacking capability. Profit or money is always an
initial motivation for criminals, who have targeted ATMs towithdraw cash even without the need for a card.
An organized group of criminals from Russia and Ukraine
has broken into internal networks at dozens of commercial

1234

banks and installed malware that allowed the group to drainbank ATMs of cash. The ATM malware family in Latin
America, Europe, and Asia are identified as ‘Carberp,' ‘Qadars,'‘Ploutus,' ‘Tyupkin,' ‘Anunak,' or ‘Carbanak' during the period
from 2009 to 2015 in Table II [19]. This malware has evolved
and has added functionality beyond banking credential theft.
The details of each malware are somewhat different. The
stealthy APT methods used by the attackers in these heists
would work across a broad range of commercial banks one byone. This group specializes in hacking into banks directly andthen working out ingenious ways to funnel cash directly fromthe financial institution itself. Since 2009, researchers havewarned that hackers were developing malicious software forATMs [14]. The online banking malware of the Carberp
program is reported to have impacted hundreds of financial
institutions around the world since 2009. In addition to its
malicious capabilities, the Carberp malware family uses a
combination of evasion techniques from the Zeus malware, andthe invisible persistence feature from other viruses, worms,
Trojans, or botnets. Hackers can resort to open source codes toachieve their goals [13, 19]. Since 2012 several ATM heists ofthis type were reportedly carried out in Russia, Europe, and theUSA. It appeared to be attacked by organized crime gangs, andthe compromised ATMs were reprogrammed to dispense cashusing malware. Ìn 2015, an international organized crime ring
had stolen up to US$1 billion from more than 100 banks in 30
nations [19]. Hackers may exploit security flaws in specificATMs, and cause the compromised machines to spew a flurry ofbills on stage. Table III illustrates the behavioral comparison of
the ATM malware family. These three cases were all arrested by
LEAs.

TABLE IITHE FUNCTIONAL COMPARISON OF ATM MALWARE FAMILY

MalwareFamilyCarberp

Identified
Companies

Federal Office forInformation Security,
BSI and Trend Micro

Finding
Time
VictimLocation

QadarsPloutus

TyupkinAnunakCarbanak

Symantec,
Microsoft,and Sophos

Symantec,
Microsoft, andSafenSoft

Symantec, Kaspersky

Group-IBand Fox-IT

Kaspersky

2009

May 2013

August 2013

March 2014

December
2014

2015

Russian

Netherlands, France,
Canada, India,
Australia, and Italy

MexicoEastern Europe, theU.S., India, China,
Russia, Israel, France,and Malaysia.

EasternEurope, theU.S.

Russia, the UnitedStates, Germany,
China, and Ukraine

Copyright ⓒ 2019 GiRI (Global IT Research Institute)

ICACT Transactions on Advanced Communications Technology (TACT) Vol. 8, Issue 5, September 2019

1235

TABLE IIITHE BEHAVIORAL ATTRIBUTE COMPARISON OF ATM MALWARE FAMILY

Category

Who

What
When

Case
An organized criminalgroup nameSuspect numbers
Arrest by

1
Carberp, Pawn Storm or
APT28
8
RussiaArrested suspects name(from Newspaper)

Germes andArashi (Alias)

USD theft in an ATM
looting
From plan to ATM heist
Arrest date

Where

ATM location

How

Money from2
Unlimited
Operations
8
USA
Elvis Rafael Rodriguez, Emir
Yasser Yeje, and Alberto Yusi
Lajud-Peña$1 Billion$45 Million

2009 ~ February 2015
March 2012
Moscow
in Russia
the financial institution

December 2012 and February 2013
May 2013
New York in the USA(More than 24 countries)
Prepaid Debit Accounts

III. SAMPLE CASE: TAIWAN ATM HEISTIn recent years there has been a tremendous increase inorganized crimes. Banks in many countries are becoming new
targets of several independent cybercrime groups. Traditionalorganization crimes have a hierarchical top-downcommand-and-control structure, but cybercrime groups tend
to involve a loose network or even a peer-to-peer
decentralized structure [1]. The group operated in closed
cells, and the suspects did not know each other involved in the
ATM heist [14]. These attacks rely upon both highlysophisticated hackers and criminal cells whose role is towithdraw the cash as quickly as possible. The crime chain is
the series of steps cybercriminals go through to transform its
ATM invasion into something of higher value. They maketheir output worth more than the sum of its inputs.
A. Specific Questions in Taiwan ATM Heist
The ATM transactions in the USA’s Unlimited Operations
require only general bank card information to effect payment,such as the bank card number, and PIN code [19]. However,Taiwan’s Russian Mafia Group in July 2016 further
compromises the ATM systems and criminals can withdraw
money without any bank card information. The ATM heist of
Taiwan First bank is based on a well-known Carberp malware
family, which is available for sharing, sale or cooperation onsuch markets. Investigators seek to explore cyber-attacks. The
arrest was made after police officers spent many sleeplessnights watching surveillance videos and checking hotel
registries in Taiwan. Putting relevant data all together
becomes essential to support or refute a cybercrime. The
questions go along the lines of whom, who, how, and why [13,20, 23]. Without understanding these root causes, it would be
difficult to use evidence from multiple independent sources,develop a strong association between a criminal and an event,and explore the incident under control.
1) Who Are Victims?
The ATM attack in Taiwan targeted the First Bank's
network. The ATM heist occurred between July 9 and 10
2016, when members of ATM heist gangs stole over USD 2
million from 41 ATMs in Taipei, New Taipei and Taichungusing malware to hack into the computer system [15]. The

3
Russian Mafia
19
TaiwanAndrejs Peregudovs, Mihail
Colibaba,
andNikolay
Penkov$2.6
Million(NT$83.27
Million)July 2016
July 2016
Taipei City, New Taipei City,and Taichung in Taiwan
the financial institution itself

Wincor Nixdorf ATM framework was targeted. They use
malicious software and defy the bank effort to strengthen the
security controls of ATM fleets. That case has demonstrated
that bank systems lack adequate security measures to stop
cybercrimes.
2) Who Are Cybercriminals?
Three cybercriminals were arrested on July 17, 2016, andeach was sentenced to prison terms of 12 years. The 19
escaped cybercriminals have been put on a wanted list, and a
total of 22 cybercriminals from six countries were involved[15].
3) How Did Hackers Do?
The heist was committed without using cards, but theATMs spat out bills. LEAs have identified some patterns totrigger withdrawals. As a result of access to internal bank
networks, hackers also gained access to ATM systems,
infected these computers with their specific malware, andlaunched the fraud command from London, UK. The
dispensing of the cash could have been triggered by a mobile
phone, a laptop, or a hacked private bank computer. The
cybercriminals use Whatsapp and other Internet-based
communication methods to communicate internally and withother criminal cells [15]. They used an old spying techniqueof dead drops and modern technology to move the stolenmoney around. A dead drop is a method of espionage
tradecraft used to pass items or information without meeting
each other directly. Another method of a live drop is used
when two persons meet to exchange items or information.
4) Why Did this Attack Happen?
Organized criminals can rent hackers to conduct attacks orhire mediators to handle the sale of stolen information.
Cybercrime as a service (CAAS) increases when the ATM
malware is sold to the highest bidders. Criminals no longer
need to rely on their knowledge, abilities, and abilities to carryout exploits, build threats, and launch attacks. This ATM
malware is sold only to selected people. Most of the infections
are from a different group and share the command and control(C&C) servers [13]. The profit attracts hackers by runningvulnerable services. Cybercriminals try to maximize their

Copyright ⓒ 2019 GiRI (Global IT Research Institute)

ICACT Transactions on Advanced Communications Technology (TACT) Vol. 8, Issue 5, September 2019financial gain while minimizing their risk [2].
B. Behavioral Attributes of ATM Malware Family
In several historical data breaches, hackers have exploited
security flaws in specific ATMs, and cause the compromised
machines to spew a flurry of bills on stage. The behavioral
comparison of the ATM malware family is listed in Table IV[13, 19]. Their local LEAs arrested these three cases. In
March 2012, the 8-member arrest of Department K group in
Moscow by the Russia Ministry of Internal Affairs(Министерство внутренних дел) was a great example ofinternational collaboration between both private industry
research and international law enforcement (see the case 1 inTable IV). A lack of awareness of cybersecurity may enhancethe vulnerability in the public or private sectors. Theirdifferences are likely due to the type of cybercrime
victimization, the effectiveness of cybersecurity measures, orthe extent of online banking services. Unlike the traditional
forms of crime, cybercrimes can act without leaving afingerprint for their actions. Not only the Internet but alsocommercial bank systems are facing increasing physical andvirtual risks [17].
TABLE IV
THE BEHAVIORAL ATTRIBUTE COMPARISON OF ATM MALWARE FAMILY

Category
An organizedcriminal group
name
Case
Arrest by
Arrest datePhysical

VirtualCriminals
under arrest
Shadowy
criminal group
Assistance
from
other
countries’
LEAs
On-premises towithdraw cash
32-bitWindowsATM
platforms
ThroughtheATM's pin pad
Nouseraccount
required
On-Premises toinstallthemalwareAvoiding
detection

Note: ‘V’ means match.

1
Carberp,
Pawn
Storm or
APT28
Russia
March
2012

2

3

Unlimited
Operations

Russian
Mafia

USA

TaiwanJuly
2016

May 2013

V

V

V

V

V

V

V

V

V

V

V

V

V

V
V

V

V

V
V

V

V

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1) Access Controls
The ATM operation is continuing to become more
complex, challenging, and costly. Most ATMs are stillrunning Windows XP, which is first released on October
2001. When Microsoft has ended support for Windows XP,
most ATM manufacturers continued to use this version [19].
The old system often opens security holes for hackers. There
will be a persistent increase in ATM robbery around theworld. The access controls of ATM theft still leave much to be
desired. They are networked devices that have many potential
weaknesses if not carefully configured, updated, andphysically secured. It is vital to improving the security
controls within banks. Although security controls can neverbe perfect for implementing and expensive to deploy, itremains of critical importance for security measures to becontinually managed, reviewed, and improved. Insufficientbudget can never be used as the reason for not taking action[21]. The default setting for any users is no or limited access.
If nothing has been correctly configured for an individual or
the groups, users should not be able to access that resource.
Banks should enforce strict access criteria, and pay more
attention to limiting and monitoring the usage of administrator
and other privileged accounts.
ATMs need remote access to communicate with bank data,so network attacks are also a possibility [14]. A trade-off
between convenience and security lies in wirelesscommunication over the public Internet or dedicatedconnections. If convenience increases, security must
decrease. The availability of access to bank ATMs frominternal network segments opens excellent opportunities forhackers. Security holes or mistakes of a system configurationin the internal bank network left sensitive databases exposed
to hackers. The strategy should remove or limit the remote
access for ATMs.
2) Physical Processa) Criminals under Arrest
Three organized criminal groups were arrested in Russia,
USA, and Taiwan. They were involved in large scale ATM
jackpotting. Their methods of operation were similar to eachother.
b) Shadowy Criminal GroupThe group allegedly used a piece of malware, pilfered cashfrom ATMs, and made millions by infecting ATMs across theworld.
c) Assistance from other Countries’ LEAs
It is difficult for any country to expand its power to othercountries. The cybercrime arrest needs assistance from other
LEAs. Arrests often take years because the cybercriminals
were located in countries where the local authorities would
not arrest them.
d) On-Premises to Withdraw Cash
LEAs can theoretically catch criminals in the act withsecurity cameras since they must be on-premises to withdraw
cash. However, it is difficult to obtain relevant evidence anddifferentiate a criminal and a regular customer.

Copyright ⓒ 2019 GiRI (Global IT Research Institute)

ICACT Transactions on Advanced Communications Technology (TACT) Vol. 8, Issue 5, September 20193) Virtual Processa) 32-bit Windows ATM Platforms
ATM malware worked on ATMs that run Windows 32-bit
operating systems.
b) Through the ATM's Pin Pad
With the help of ATM malware, cybercriminals were able
to empty the infected ATM cash cassettes by issuingcommands through the ATM's pin pad.
c) No User Account Required
The malware allows its operators to withdraw cash from
ATMs without the requirement of any payment card.
d) On-Premises to Install the Malware
Cybercriminals started by unlocking an ATM's
enclosure and infected the computer with a piece of malware.
Days later, they returned to the computer and dispensed fromthe ATM without the need for user account verification.
e) Avoiding Detection
The ATM malware kept the exploit hidden most of thetime and had several features that helped it avoid detection[13]:
 It was only active at specific times of the night on certain
days of the week.
 ATM malware implements anti-debug and anti-emulation
techniques The malware could disable the anti-virus system from theinfected system.
IV. COMPREHENDING TAIWAN ATM HEIST: FROMCYBER-ATTACK PHASES TO INVESTIGATION PROCESSES
A. Embedding Cyber-attack Phases into the ATM Heist
Investigation
According to public reports surrounding the incident
investigation of Taiwan ATM heist, criminals deleted tracesof the cyber-attack to prevent from detecting irregularities in
the ATM behavior. Some malware behaviors and file names
have been identified from the cyber-attack phases [14, 15, 19,24].
1) Reconnaissance and Footprinting
In this phase of reconnaissance and footprinting, criminals
gather information about computer systems, reveal systemvulnerabilities, and find ways to intrude into the cyberspace[18]. Most exploits are dependent on operating systems,
applications, ports, or services. Hackers may perform
reconnaissance for about 2 to 3 times to gather a big-picture
view of a network or servers before they attempt an exploit. It
identifies the IP addresses, open ports, running services, andoperating systems in the target network [22, 24]. Footprinting
identifies the operating system, service pack or patches of thetarget, gathers the maximum information about the computer
system or a network, evaluates the security of any IT
infrastructure, and determines the follow-up attack path. It is
used to get detail information on a specific target. For
example, if a server is listening on port 80, it is running the
HTTP protocol and is very likely a web server. It is often usedas part of a more significant reconnaissance attack. Increased
access to the Internet has enabled cybercriminals to perform
reconnaissance on their targets. Cnginfo.exe and1237

cnginfo_new.exe can read the information inside the ATM in
the phase of reconnaissance and footprinting.
2) Scanning or Enumeration
In this phase of scanning and enumeration, hackers gather
in-depth information on the victims. Enumeration often
occurs after scanning [17]. The more hackers know inadvance, the fewer surprises they will have. They runscanning activities to infer vulnerabilities on the Internet.
Once a computer is found vulnerable, they attempt to control
or infect that computer based on the inferred vulnerability.
Running a ping sweep or a network mapper can explore what
systems are on the network. Running a vulnerability scanner
can also determine which ports may be open on a particularsystem. Enumeration refers to actively connecting to a target
system, and identifies usernames, computer names, network
resources, shares, and services. It also refers to actively
connecting to a target system to acquire this information.
Once a vulnerability is identified, a cyber-attack is relatively
easy to disguise. There is no clear evidence from criminals'
scanning or enumeration. These activities can be found fromthe target's firewall log files. Auditing logs can be monitored
to detect threatening incidents promptly. By monitoring logs
of digital evidence, LEAs can look for the triggers orsomething suspicious.
3) Gaining AccessIn the phase of gaining access, these attacks can accessinsecure access [18]. Hackers can gain access to the system,
crack a password, and escalate privileges. The hackers
initially compromised a vulnerable telephone recording
computer used by the targeted bank in order to establish
network access. Cngdisp.exe and cngdisp_new.exe
potentially contain more robust capabilities than cngdisp.exe,
executed the function of dispensing bills in the phase ofgaining access.
4) Maintaining Access
Gaining access to a connection does not mean hackers canaccess everything. The objective of maintaining access is toensure that hackers can have long-term access. Hackers used
this network access to move laterally within the targetedbank's network and subsequently gained access to deliver
software updates across the network. They use the update
service to send malware to the target ATMs. The malware
masqueraded as a software update. They utilized the remotecommands to empty the cash-carrying cassettes in the infected
ATMs. There was no action required at the ATM except thecollection of the money.
5) Covering Tracks
In the final phase of covering tracks, hackers attempt toconceal their trails, manipulate the event logs, and avoid
detection by the system administrator or LEAs. Log files
contain information about every computer activity. Hackers
may try their best in hiding or obscuring the applications theyleave behind. That leads hackers into paying attention to log
files. Covering tracks consists of removing or altering log
files, hiding files with unclear attributes, or using tunneling
Copyright ⓒ 2019 GiRI (Global IT Research Institute)

ICACT Transactions on Advanced Communications Technology (TACT) Vol. 8, Issue 5, September 2019

protocols to communicate with the information system [18].
Hackers need to evade detection, erase evidence of acompromised computer, and remove the portions of logs thatcan reveal their presence. A significant amount of malware
deploys various anti-forensics tricks in an attempt to make theanalysis more difficult. In the final phase of the cyber-attack,the criminals deleted (sdelete.exe) components of themalware employed in the ATM heist. Sdelete.exe and batch
file cleanup.bat deleted the other programs in the phase ofcovering tracks [15].
B. Detecting ATM Heist Using ISO/IEC 27043:2015
Incident Investigation Processes Classes
The regulation of cyberspace law often lags behindtechnological development in cybercrime. Hackers will try
their best to hide their identity and reduce their chances ofdetection across jurisdictional broader. A threat determines
the risk, but for each risk, LEAs can determine the following
countermeasures. The cybercrime investigation processes in
ISO/IEC 27043:2015 are purposely designed at an abstractlevel for different types of cybercrimes [11]. In Table V, thecybercrime investigation processes in cyber-attack scenarios
from LEAs’ perspective can be further discussed andanalyzed into the following processes classes: Readiness,
Initialization, Acquisitive, Investigative, and Concurrent.
TABLE VCYBERCRIME INVESTIGATION FROM ISO/IEC 27043:2015

Processes
Class
Readiness

Initialization

Acquisitive

Investigative

Concurrent

PeopleProcess/Activities

Technology

Pre-incident
ICT
investigation/ plan
Governanceand prepare
Cybercrime
Live
First
investigation/
forensics
responders
respond
Physicalinvestigation/Deadidentify, collect,
Lab analysts
forensics
acquire,andpreserve
Event
Digitalreconstruction/
forensic
LEAs
understand, reportanalysisand close
Obtaining Authorization Process, Documentation
Process, Managing Information Flow Process,Preserving Chain of Custody Process, Preserving
Digital Evidence Process, and Interaction with
Physical Investigation Process
Systemadministrators

1) Readiness Processes Class: Prepare the ICT
Governance from System Administrators
The first class of readiness processes is prepared inadvance for an investigation. Investigators can plan incident
detection, identify potential digital evidence sources, analyze
digital data, and explore the truth in a legally proper way. This
class deals with pre-incident investigation processes andensures that incident detection systems are in place [5].
Deploying a digital forensic readiness program can favorably

1238

impact LEAs by maximizing the potential of digital evidence
and minimizing the time and costs of an investigation [11].
The investigators of data breaches can initiate some plans fortaking the actions, reinforces a direct relationship between
cybercrime investigation and fact-finding. Cybercrime
prevention requires the participation of Internet users, thesystem administers, or enterprises to maintain personal orcommercial data. The whole society should be encouraged toparticipate more fully and effectively in cybercrime
prevention in order to provide for a harmonious online world[21]. A supplementary strategy is intended to achieve the goalof information security. This method can assist banks or LEAs
in dealing with today’s ever-increasing ATM heist.
2) Initialization Processes Class: Initiate the LiveForensics from First Responders
The second class of initialization processes deals with
uncovering the potential digital evidence and searching for
traces of digital evidence in a legal process. It includes
incident detection, first response, and preparation [11]. The
implementation of cybercrime investigation procedures
includes the responsibilities for establishing a direction for its
execution. The identification of appropriate best practices
should develop a cybercrime investigation strategy,
implement risk management, and meet the need for aninvestigation with acceptable efforts. There is an opportunity
to actively collect potential evidence in the form of log files or
network traffic records in a forensically sound manner. Live
forensics primarily targets volatile data from a runningsystem. Ignoring the volatile data of computer memory is
impossible in collecting digital evidence. It can be the firststep toward an incident response scenario. Live forensics cananalyze volatile data, system running processes, cachedprocesses, network connections, and opened ports without
shutting down a system. Practitioners can directly makecontact with the suspect and ask what has happened.
Investigators can locate, extract, and analyze data from digital
devices, which LEAs interpret to serve as legal evidence [16].
3) Acquisitive Processes Class: Perform the Dead
Forensics from Lab Analysts
The third class of acquisitive processes deals with thephysical investigation of a case where potential digital
evidence is identified and handled. It includes identification,acquisition, transportation, and storage in potential digital
evidence [11]. In dead forensics, practitioners canconveniently minimize system modification when working
with a copy of a write-protected drive at laboratories. An
examination of the computer is conducted systematically toensure the admissibility of the evidence. The investigatorshould achieve continual improvement of the cybercrime
investigation and take reactive activities based on the resultsof the case reviews or other relevant information. The
investigation procedure will continue to evolve together withthe requirement to incorporate new evidence and associatedknowledge. LEAs have actively gathered evidence to support
a legal defense [23].

Copyright ⓒ 2019 GiRI (Global IT Research Institute)

ICACT Transactions on Advanced Communications Technology (TACT) Vol. 8, Issue 5, September 20194) Investigative Processes Class: Conduct the Digital
Forensic Analysis from LEAs
The fourth and last class of investigative processes
develops a likely sequence of events. It includes investigating
the incident, analyzing the evidence, interpreting results fromthe analysis, and reporting on results of the digital evidence.
Investigators can examine the pieces of evidence to measureperformance against the determined objectives and report theresults to the appropriate recipients for review. A singularstrategy can not resolve the majority of cybercrimechallenges. Technical minds alone cannot solve the issue ofprosecuting cybercriminals. Given limited time andresources, it is essential to maximally leverage knowledge,
capabilities, and investments in a range of public-private
partnerships to improve foundations of trust and enhanceagility and resilience.

leverage investments in a range of societies to assure societal
services. The ATM withdrawals happened so quickly thatnone of the commercial banks involved noticed in time to stop
the perpetrators. ATM technologies are evolving fast andmaking payments more convenient. Organizations need abalance between security and functionality in information
security. This study outlines a set of profiling cybercrime
investigation that aims to identify digital pieces of evidence inthe face of increased complexity and vulnerability in hacking
activities. It is our sincere hope to bring the technical details
to the attention of information security specialists and tominimize risks by preventing information security incidents.
A small sacrifice inconvenience can be useful to prevent an
attack on the ATM's door. ICT governance should be
employed by banks to heist ATM money with more barriers.

5) Concurrent Processes Class: Take Place in Company
with these Processes Classes
The following concurrent processes class takes place incompany with the former processes classes [5, 11, 20].
a) Obtaining Authorization Process
Having authorization from the appropriate authorities
makes sure that the appropriate countermeasures are ready tosolve it.
b) Documentation Process
Investigators must maintain documentation of digital
evidence from the beginning of the e-discovery process until
the end.
c) Managing Information Flow Process
Information flow could describe the use of trusted PKI andtime stamping to identify the exchange of digital evidence
between each of the processes in the same investigation.
d) Preserving Chain of Custody Process
The documentation comprises the chain of custody form
and records relating to the evidence analysis.
e) Preserving Digital Evidence Process
In order to preserve the integrity of the digital evidence,
investigators should guarantee that the original evidence is
not changed.
f) Interaction with Physical Investigation Process
There are some complex interactions with the physicalinvestigation according to the digital investigator’s needs andfast adaption to changing boundaries, scope, or investigation
objectives. All of the complexities must be simplified toensure an efficient investigation.

[1]

1239

REFERENCES

V. CONCLUSIONSICT innovations are not only set to bring enormous benefits
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for the dissemination of malware. Criminals increasingly use
sophisticated tools and methods to commit their cybercrimes.
Major information systems of modern society are under theburgeoning attack. Cybersecurity for banking or financial
institutions becomes a vital business enabler to enhancecustomer confidence and bring in more business. It is vital to

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Investigation Principles and Processes,” ISO Office, 2015.
[12] Jewkes, Y, and Yar, M., Handbook of Internet crime, Willan
Publishing, pp. 173-193, 2009.
[13] Kao, D. Y., “Exploring the Cybercrime Investigation Framework of
ATM Heist from ISO/IEC 27043:2015, ” IEEE ICACT 2017 (19thInternational Conference on Advanced Communications Technology),
Pyeong Chaung, South Korea, 2017.
[14] Kao, D. Y., “ATM Heist Threats: a Proposed ICT Governance
Strategy,” IEEE ICACT 2019 (21th International Conference on
Advanced Communications Technology), Pyeong Chaung, South
Korea, pp. 610 - 615, 2019.
[15] Law and Regulations Retrieving System, “Criminal Appeals No.
593/106 in Taiwan High Court,” Judicial Yuan, May 18, 2017.
[16] Marcella, A. J., Menendez, D., Cyber Forensics: A Field Manual forCollecting, Examining, and Preserving Evidence of Computer Crimes(2nd Edition), Auerbach Publications, pp. 1-26, 2008.
[17] Mehan, J. E., Cyberterror, Cybercrime, and Cyberactivism: An
In-Depth Guide to the Role of Security Standards in the Cybersecurity
Environment (2nd Edition), IT Governance Publishing, pp. 25-58,
2014.
[18] Oriyano, S. P., CEH v9: Certified Ethical Hacker Version 9 Study
Guide (3rd Edition), John Wiley & Sons, Inc., pp. 1-222, 2016.
[19] Sancho, D., Huq, N., and Michenzi, M., “Cashing in on ATM
Malware: A Comprehensive Look at Various Attack Types,” Trend

Copyright ⓒ 2019 GiRI (Global IT Research Institute)

ICACT Transactions on Advanced Communications Technology (TACT) Vol. 8, Issue 5, September 20191240

Micro Forward-Looking Threat Research (FTR) Team and Europol’s
European Cybercrime Centre (EC3), 2017.
[20] Shipley, T. G. and Bowker, A., Investigating Internet Crimes: An
Introduction to Solving Crimes in Cyberspace, Elsevier Inc., pp.
21-38, 2014.
[21] Smith, R. G., Cheung, R. C. C., and Lau, L. Y.C., Cybercrime Risks
and Responses Eastern and Western Perspectives, Macmillan
Publishers Limited, pp. 67-211, 2015.
[22] Spitzner, L., Honeypots Tracking Hackers, Addison-Wesley, pp. 8-20,
2002.
[23] Stephenson, P., Official (ISC)2® Guide to the CCFP CBK, Auerbach
Publications, pp. 293-404, 2014.
[24] Walker, M., CEH Certified Ethical Hacker All-in-One Exam Guide(2nd Edition), Graw-Hill Education, pp. 35-198, 2014.
Da-Yu Kao received the B.S. and M.S. degree inInformation Management from Central Police
University, Taiwan, in 1993 and 2001, the Ph.D.
degrees in Crime Prevention and Correction fromCentral Police University, Taiwan, in 2009,
respectively. From 1993 to 1996, he was with Taipei
City Police Department, Taiwan, where he was an
information technology police officer involved in thedevelopment of policing information systems. From1996 to 2007, he was with Criminal Investigation Bureau, National Police
Administration, Taiwan, where he was a detective and forensic police officer
in cybercrime investigation and digital forensics. From 2007 to 2013, he waswith Maritime Patrol Directorate General, Coast Guard Administration,
Taiwan, where he was an information technology section chief in thedepartment of information and communication. Since 2013, he has beenwith Central Police University, Taiwan, where he is currently an associate
professor in the Department of Information Management. His researchinterests include cybercrime investigation, digital forensics, digital evidence,
information management, criminal profiling, and cyber criminology.

Copyright ⓒ 2019 GiRI (Global IT Research Institute)

ICACT Transactions on Advanced Communications Technology (TACT) Vol. 8, Issue 5, September 20191242

A High-Performance Parallel Hardware
Architecture of SHA-256 Hash in ASIC
Ruizhen Wu*, Xiaoyong Zhang**, Mingming Wang*, Lin Wang**Inspur Electronic Information Industry Co.,Ltd, Xi’an Shaanxi Province China**Biren Technology Ltd, Shanghai China
wuruizhen@inspur.com , xyz8070@126.com , wangmingming02@inspur.com , wanglinlc@inspur.com

Abstract—The SHA-256 algorithm is used to ensure theintegrity and authenticity of data in order to achieve a goodse curity thus is playing an important role in various
applications, such as e -transactions and bitcoins. The
SHA-256 computation capacity is a main research directionof Hashing Algorithm. In order to improve the computation
capacity of hardware, the proposed design first use s pipeline
principle and circuitry of timing prediction to find a moste fficient architecture for implementation. Then it is
optimize d with hash function and hardware characteristics
to give a high-performance hardware architecture of
SHA-256 hash. Three pipelines are used to replace thecritical path in the round functions which can shorten thetiming path, and divide the computation chain into
independent steps. Multi-computation of SHA-256 isworking in parallel pipelines, indicating that thecomputation capacity can be 3 times of that with standard
SHA-256 implementation. The proposed SHA-256 hardware
architecture has be en implemented and synthesized withIntel 14nm technology. Simulation and synthesis results
show the proposed SHA-256 hashing throughput can be
improved by 3 times with 50.7% power reduction, at an area
cost of 2.9 times compared to that of the standard
implementation.
Keyword—Application specific integrated circuits ,Cryptography, High -speed integrated circuits, Low-powere le ctronics

I. INTRODUCTIONS

ECURE hashing algorithm is used to ensure the data
integrity and authenticity while being stored andtransferred. Hash functions take input data of arbitrary
length and convert them into some fixed data, called hashvalue or message digest. The SHA-256 of hashing———————————————————————
Manuscript received Jan. 10, 2019. This work is a follow-up of the invitedjournal to the accepted & presented paper of the 21th International Conference
on Advanced Communication Technology (ICACT2019), and Grant ID is
ICACT-20190011.
Ruizhen Wu is with the Inspur Electronic Information Industry Co.,Ltd,
Xi’an, Shaanxi 710071 China. (Phone: +86 15909206044; e-mail:wuruizhen@inspur.com).
Xiaoyong Zhang is with the Biren Technology Ltd, Shanghai 201210
China. (E-mail: xyz8070@126.com).
Mingming Wang is with the Inspur Electronic Information Industry Co.,Ltd,
Xi’an,
Shaanxi
710071China.
(E-mail:wangmingming02@inspur.com).
Lin Wang is with the Inspur Electronic Information Industry Co.,Ltd,
Xi’an, Shaanxi 710071 China. (E-mail: wanglinlc@inspur.com).

algorithm is playing an important role in various
applications. Almost all e-transactions, high-throughput
designs of security schemes are needed. Bitcoin is a newand popular use of SHA-256, as the POW (“Proof ofWork” [1]) mentions in the Bitcoin protocol: the POW
requests a huge number of SHA-256 computations to finda proper 32-bit number to satisfy the protocol requirement.
The first finder is awarded by bitcoin, which means thecomputation capacity of SHA-256 is the key factor to getawarded, therefor the main research direction.
The SHA-256 hash architecture acts more and more
important nowadays thus several improved designs areproposed. To embed a security engine in a RFID tag, twocompact SHA-256 implementation are presented, a low
area design and a low power design [2]. To achieve theimprovement several adder cycles and adder selectors
were added in the round computation which made it very
suitable for power-area balanced applications.
One application of ideas and techniques from functional
languages to the model-driven design and synthesis of
hardware artifacts for SHA-256 was proposed in [3]. The
co-design of hardware and software not just made the
SHA-256 algorithm easier to implement, but also gave amore effective way to optimize the performance ofSHA-256 from software to hardware based on designer’s
need.
However the most challenging request of SHA-256 ishigh processing speed and low power in hardware. An
optimized pipelined architecture of SHA-256 hash function
has been implemented in [4] which used custom data paththat enforces the reuse of modules based on which novel
processor architecture was implemented. Reference [5]proposed a SHA-256 unfolding design based onreconfigurable hardware modules. The complex linear
computing of SHA-256 was reconfigured by newly added
computation modules. Reference [6] implemented
SHA-256 architecture based on operation rescheduling tominimize the critical path delay. Reference [7] proposed amore effective hardware to control the SHA-256
computation, which was using the finite state machine(FSM).
The purpose of this paper is to provide a hig hCopyright ⓒ 2019 GiRI (Global IT Research Institute)

ICACT Transactions on Advanced Communications Technology (TACT) Vol. 8, Issue 5, September 2019

Kt

H
G

F

Ch(E,F,G)

performance parallel computation hardware architecture in
ASIC of SHA-256 hash. The organization of this paper is:
Section 2 describes the classic SHA-256 algorithm;
Section 3 uses the pipeline principle and circuitry timing
prediction to find the most efficient pipeline architecture
for SHA-256. Section 4 presents the proposed SHA-256
parallel computation hardware architecture with 3
pipelines. The implementation results and comparison
with other designs are in Section 5. The last section
provides the conclusions.

Σ1
E

D
C
B
A

Maj(A,B,C)

II. SHA-256 A LGORIT HM
This section describes the function of SHA-256 hash. A
detailed description of the SHA-256 hashing algorithm canbe found in the official NIST standard [8]. The SHA -256
computation can be divided into 2 steps. The first step is topre-process the original messages. It involves message
padding and expanding the message for the roundcomputation. The padding means appending bits
according to some rules until the total length is integer of
512-bit. Afterwards every 512-bit will be expanded to 64*32
bit for SHA-256 round computation.
Here we use “t” to indicate the number of transformation
rounds.

1243

Σ0

Wt

Input
R0
R1
R2
R3
R4
R5
R6
R7
R8
R9
R10
R11
R12
R13
R14
R15

σ1

σ0

Fig. 1. SHA-256 hashing algorithm

When 0≤t≤15:

The second step is called round computation shown inleft part of dotted line in Fig. 1 is to obtain the “a”~ “h”,
which can be calculated by:When 16≤t≤63:

(4)

(1)
The first 16 W t are input messages. And after that theothers are from iterative operation. In equation (1) the σ iscalculated by:
(2)

(5)

(3)

(9)

In (2) and (3), the ROTRn(x) means a right rotation of x byn bits, and SHRn(x) means shift right of x by n bits.
The whole SHA-256 computation is showed in Fig. 1.

(10)

(6)
(7)
(8)

(11)
(12)
(13)
The first round of a, b, c, d, e, f, g and h are assigned by
the initial value of SHA-256 definition. The Kt is a constantin 32-bit and 64 values overall. And the four function
computations are showed in (14)-(17):
(14)
(15)
(16)

(17)
The

represent bitwise XOR operation, therepresent bitwise AND operation and the

bitwisecomplement operation.

Copyright ⓒ 2019 GiRI (Global IT Research Institute)

ICACT Transactions on Advanced Communications Technology (TACT) Vol. 8, Issue 5, September 2019

Each round of (6)-(13) can generate 8 hash values, they
were showed in the right part of Fig. 1 and calculated by:
(18)

1244

parallel working flow. So the new path delay with n stage
pipelines inserted is:
(27)

(19)
(20)
(21)
(22)
(23)
(24)
(25)
The final output is obtained by the 64th round has hvalue as below:(26)
III. PIPELINE A RCHIT ECT URE
It is clear from [4]-[7] that to achieve high processing
speed and low power in hardware the pipeline architecture
is a good choice of implementation which has gained a lotof interests. From hardware design perspective thepipeline architecture can work in various forms as long as
the algorithm calculation units can be divided to satisfy
the pipeline architecture needs.
So to find a most efficient pipeline architecture for highprocessing speed and low power in hardware we need toconsider the change of delay and area cost in SHA -256
hardware architecture.
A. State-of-art Pipeline principle

D

D/n

S

Which means the n stage pipelines cost can use (27)-(29)to summarize as:(30)

B. Update the pipeline principle
Evolve the theory and model of Ⅲ.A with Ⅱ’s SHA-256
algorithm to update the pipeline architecture, the N stage
pipelines insertion of Fig. 2 can be described as:

ABCDEFGH(1)n:1
MUX D/n

S

D/n

S

D/n

S

1:n
DE
MUX

ABCDEFGH(n-1)

Fig. 3. N stage pipeline insertion with SHA-256

From Fig. 3 it is clear to see that besides the (30)considering FFs’ cost there are additional cost needed for
MUX and DEMUX’s input and output. So for A~H’s
calculation each pipeline insertion needs an extra 8
registers to temporarily store values of A~H for MUX andDEMUX. No matter how many pipelines are inserted the
hardware architecture only needs a pair of MUX andDEMUX. Taking
Intel 14nm technology devices’parameter for reference to calculate the area cost with (28),the area of (28) can be updated to:(31)

Original critical pathS

To give a most efficient pipeline architecture means tofind an optimum solution which can have the smallest
frequency per area. And that equals to the same questionof finding out the smallest area cost for maximum
achievable frequency. Considering the maximum
achievable frequency can be described as “1/D” so thearea cost is:(29)

ABCDEFGH(0)The pipeline architecture’s core concept is to use FFs(Flip-Flops) to divide the serial working flow and rebuild it
into a parallel working flow. So the timing model based on
the hardware function requirement have to be built first tofind out the most efficient hardware architecture solution.
From [9-15] we used the state-of-art pipeline method toconsider the relationship between delays and timing
combinations with a piecewise linear model. Consider theserial working flow’s path delay is “D” and area is “G”.
And the parallel working flow’s one stage pipeline pathdelay is “S” and area is “L”. Then the relationship between
the serial working flow and parallel working flow can be
described as Fig. 2 showed.

D/n

The new area with n stage pipelines inserted can be
described as:
(28)

D/n

S

n stage pipelines insertion
Fig. 2. N stage pipeline insertion into a critical path

The serial working flow can be described as an originalcritical path which can insert n stage pipelines to work as a

The Lm&d is the area cost of MUX and DEMUX, which isalmost 0.25L of (28). The 8*n*L represents the extra 8
registers area cost for n pipelines insertion.
Do the same calculation to find the delay relationship of
MUX and DEMUX with (28) to update the (27):(32)
The 0.46 here is because in STA report it can find that
Copyright ⓒ 2019 GiRI (Global IT Research Institute)

ICACT Transactions on Advanced Communications Technology (TACT) Vol. 8, Issue 5, September 2019

one AND gate’s delay is almost 0.46 time of a FF’s delay.
Use (31) and (32) to update the cost equation as shown in
(30):

1245

design is to optimize the (4)-(17) in order to get a better
performance in 3 steps.
A. Critical Path Analysis
To analyze the critical path of SHA-256 we unfold thecomputation steps, which are showed in Fig. 5.
Σ1
E(t)
D(t)

(33)

Ch

F(t)

E(t+1)G(t)
K+W(t)In (33) only the “n” is a variable, the others are all
decided by the technology lib used which can beconsidered as fixed values here. So the optimum solutionmeans to find out the minimum value of (33).
With the actual technology lib’s parameters. the fixedvalues of (33) can be calculated as:
(34)
(35)
(36)
(37)
Calculating the (33) with (34)-(37), the relationship curveof cost’’ with different n is showed in Fig. 4.

A(t+1)

H(t)
A(t)

Σ0

B(t)

Maj

C(t)
Fig. 5. Critical path

The symbols in Fig. 5 are same as Fig. 1, and the “+”represents the addition modulo 232. As known the mostproblematic characteristic of SHA-256 is the addition
modulo 232, which slows down the speed heavily versus
the other calculation steps [16]. Based on this fact, we findthe most critical path in SHA-256 round calculation. As Fig.
5 shows, the most critical path is showed in dotted line,
which means from calculation e(t) to obtain a(t+1) in eachround is the longest path worth optimizing (same as otherlong path with 3 “+” calculations).
B. Break Critical Path
To optimize the SHA-256 computation it needs to breakthe critical path into shorter paths thus make it possible forthe whole computation chain to work at a higher frequency.
For this need, we consider each addition modulo 232
calculation as one basic unit of SHA-256 calculation ineach round. To separate all calculations we insert FFs toeach minimum unit.
Σ1
E(t)
D(t)

F(t)

Ch

G(t)

T1
(t)

Fig. 4. Relationship curve of cost’’ with different n

According to Fig. 4 it is clear to see that when n=3 thecost gets the minimum value which means the mostefficient pipeline architecture for SHA-256 calculation withIntel 14nm technology lib is 3 pipelined architecture.
IV. PROPOSED DESIGN
To realize the 3 pipeline architecture of SHA-256 weneed to divide the SHA-256 calculation into 3 parallelworking flow in an efficient way. From the SHA-256
hashing algorithm we can see what limits the computation
speed most is (4)-(17). In fact the (1)-(3) can be done quite
earlier but has to wait a very long time for (4)-(17) to finish
a round of whole SHA-256 computation. The proposed

E(t+1)

T11
(t)

T12
(t)

K+W(t)

A(t+1)

H(t)
A(t)

Σ0

B(t)

Maj

T2
(t)

C(t)
Fig. 6. FFs insertion

As Fig. 6 shows, we insert 4 32-bits FFs (The grey
rectangles) in each round of SHA-256 to separate all basic
units. With the insertion, there is only one addition
modulo 232 calculation between each two FFs. And the T1(t) and T2 (t) mean the FFs for T1 and T2 calculation as

Copyright ⓒ 2019 GiRI (Global IT Research Institute)

ICACT Transactions on Advanced Communications Technology (TACT) Vol. 8, Issue 5, September 2019

what equation (4) and (5) show, n means the round numberof whole SHA-256 computation. T11 (t) and T12 (t) are
intermediate results for T1, “t” the same as before.
Because the long path is broken， we can run almost 3
times faster than before, but each round will take 3 cycles
now.
C. Reschedule With Parallel Pipeline
In standard SHA-256 computation, variable “A” to “H”
are calculated one after another. But most of them are justa bit shifting operation which is much easier compared toaddition modulo 232 calculation. Consequently, we
reschedule the SHA-256 computation based on step B’s
basic units with parallel pipeline.

E(t)

Σ1

F(t)

Ch

D(n)
E(t+1)

T11
(t)

G(t)

T1
(t)

CFG
Kt+Wt(0)ABCDEFGH(0)Kt+Wt(1)ABCDEFGH(1)Kt+Wt(2)

B(t)

Maj

DE
MUX

Fig. 9. Parallel computation SHA-256 hardware architecture

The proposed architecture gains 3 times performancewith a 3 times higher clock frequency, compared to thestandard architecture.
V.

RESULT A ND DISCUSSION

The proposed high performance parallel computation of
SHA-256 is successfully implemented in Verilog. The
hardware architecture is fully verified at RTL level andsynthesized with Intel 14nm technology lib. The
comparison results are showed below:

A(t+1)
Σ0

SHA-256
computation

TABLE IHARDWARE C OMPARISON R ESULTS

H(t)
A(t)

MUX

ABCDEFGH(2)

T12
(t)

K+W(t)

1246

Standard
ProposedT2(t)D(t+1)
C_D
(t)

C(t)

Fig. 7. Variable update

As Fig. 7 showed, to achieve parallel computation, a key
intermediate FF “C_D” is added, to preserve C and update
D later. With this rescheduling the SHA-256 is separated
into 3 individual steps to update “A” ~ “H”, in subsequent
3 cycles. The functional diagram in sequence is showed inFig. 8.
clk
Hash0 A-H input EFGH(0), K+W(0) ABC(0)D0(0)

EFGH(1), K+W(1)ABC(1)

D(1)

Hash0 A-H output FGH(1)BC(1)

ADE(1)

FGH(2)BC(2)

ADE(2)

Hash1 A-H input EFGH(0),K+W(0) ABC(0)D(0)

EFGH(1),K+W(1)ABC(1)

D(1)Hash1 A-H output FGH(1)BC(1)

ADE(1)

FGH(2)BC(2)

ADE(2)

Hash2 A-H input EFGH(0),K+W(0) ABC(0)D(0)

EFGH(1),K+W(1)ABC(1)

D(1)

Hash2 A-H output FGH(1)BC(1)

ADE(1)

FGH(2)

BC(2)Clock(ps)1959653

Area(μm2)4916.714272.6

Power(mW)
3.3794
6.855

The proposed high performance parallel computation
hardware architecture of SHA-256 is 3 times faster than thestandard architecture as we expected.
The area cost to achieve this improvement is 2.90 times
compare to standard SHA-256, which is because there arereused function modules to save area.
The power of proposed parallel SHA-256 is just 2.03
times of standard SHA-256 to have same 3 times output.
That’s because the sequential logic consumes muchbigger power than the combinational logic, and the
proposed architecture can exactly save much sequential
logic.
VI. CONCLUSIONS

ADE(2)

Fig. 8. Rescheduled parallel pipeline SHA-256

As the Fig. 8 shows, with parallel pipelines three
SHA-256 hashes can be calculated at the same time. The
hardware architecture is showed in Fig. 9.

The parallel hardware architecture is the best solution toachieve high processing speed and low power
consumption in hardware. This paper first builds the speed
and area model with SHA-256 algorithm and technology lib
to find the most efficient pipeline architecture is 3 pipeline
stages for SHA-256 realization. Then it is dividing andupdating the architecture with SHA-256 calculation
unfolding by FFs to give a high performance hardware
architecture for parallel computation in AISC. The design
is synthesized with Intel 14nm technology and thecomparison results demonstrated the improvement of 3
times computation speed with 50.7% power consumption,
at a cost of only 2.9 times area.

Copyright ⓒ 2019 GiRI (Global IT Research Institute)

ICACT Transactions on Advanced Communications Technology (TACT) Vol. 8, Issue 5, September 2019

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S. Nakamoto. (2008). Bitcoin: A Peer-to-Peer Electronic Cash System.
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1247

Technology, Northwestern Polytechnical University, Shaanxi
Province, China, in 2003, and the second bachelor degree was earned inelectronic science and technology, in Institute of Microelectronics,
Tsinghua University, Beijing City, China, in 2005.
He has worked in Xi’an, Shaanxi Province, China, since 2005, in the wirelessdepartment for Infineon Technology at first, and now Biren technology. His
current job is SoC HW design managerst

Mingming, Wang was born in China, Oct 1
1986. Master. The Master degree was earned in
Computer Application Technology in Xi’an Universityof posts & Telecommunications, Shaanxi Province,
China, in 2011, and the bachelor degree was earned inelectronic science and technology, in Xi’an University ofposts & Telecommunications, Shaanxi Province, China
in 2008.
He has worked in Inspur Electronic Information Industry Co.,Ltd since 2019.
Lin, Wang was born in China, Dec. 1st. 1971. Masterof Sci. The master degree was earned in Dept. ofElectrical Engineering, Fudan University, Shanghai,
China, in 1998. His majority is microelectronics andphysics on semiconductor and semiconductor device.
He worked in Shanghai Nortel Semiconductor andBroadcom, focusing on communication chipdevelopment after his graduation.
He is now the Director of SoC R&D in Inspur Electronic Information Industry
Co.,Ltd.

Ruizhen, Wu was born in China, Jan 1st 1986. PhD.
The PhD was earned in School of Microelectronics of
XIDIAN University, Shaanxi Province, China, in2014. The major field of study is Asynchronous
Circuits design, 5G CODEC and AI.
He has worked in Hangzhou, Zhejiang Province, China,
since 2014, in the 2012 communication lab of Huawei
at first, then Intel iCDG, and Inspur Electronic
Information Industry Co.,Ltd now
Xiaoyong, Zhang was born in China, Nov 5th
1980. Bachelor. The first bachelor degree was earnedin automation, in School of Marine Science andCopyright ⓒ 2019 GiRI (Global IT Research Institute)