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  <front>
    <journal-meta />
    <article-meta>
      <title-group>
        <article-title>Data Analytics to Detect Evolving Money Laundering</article-title>
      </title-group>
      <contrib-group>
        <contrib contrib-type="author">
          <string-name>Murad Mehmet</string-name>
          <xref ref-type="aff" rid="aff0">0</xref>
        </contrib>
        <contrib contrib-type="author">
          <string-name>Duminda Wijesekera</string-name>
          <xref ref-type="aff" rid="aff0">0</xref>
        </contrib>
        <contrib contrib-type="author">
          <string-name>George Mason University mmehmet@gmu.edu</string-name>
          <xref ref-type="aff" rid="aff0">0</xref>
        </contrib>
        <contrib contrib-type="author">
          <string-name>dwijesek@gmu.edu</string-name>
          <xref ref-type="aff" rid="aff0">0</xref>
        </contrib>
        <aff id="aff0">
          <label>0</label>
          <institution>Keyword: Data Analytics; Social network analysis; Anti Money Laundering; Dynamic Risk Model ; Money laundering Risk</institution>
        </aff>
      </contrib-group>
      <pub-date>
        <year>2013</year>
      </pub-date>
      <abstract>
        <p>- Money laundering evolves using multiple layers of trade, multi trading methods and uses multiple components in order to evade detection and prevention techniques. Consequently, detecting money laundering requires an analytical framework that can handle large amounts of unstructured, semistructured and transactional data that stream at transactional speeds to detect business-complexities, and discover deliberately concealed relationships. Based on our prior work and a static risk model proposed in the Bank Security Act, we propose a dynamic risk model that assigns a risk score for every transaction being a potential component of a larger money-laundering scheme. We use social networks to connect missing links in such potential transaction sequences. Taken together we can provide a financial sector independent risk assessment to submitted transactions. The proposed risk model is validated using data from realistic scenarios and our already developed money laundering evolution detection framework (MLEDF) that we developed earlier using sequence matching, case-based analysis, social networks, and complex event processing to link fraudulent transaction trails. MLEDF has components to collect data, run them against business rules and evolution models, run detection algorithms and use social network analysis to connect potential participants.</p>
      </abstract>
    </article-meta>
  </front>
  <body>
    <sec id="sec-1">
      <title>INTRODUCTION</title>
      <p>Money laundering (ML) is a major issue for the
Department of Homeland Security (DHS) and US Treasury.
Powered by modern tools, money launderers use complex
schemes to avoid being detected by anti-money laundering
(AML) systems. They dynamically evolve, expand and contract
over fraudster networks in different countries. Social Network
Analysis (SNA) techniques [1] are used by government
agencies to track terrorist activities and networks. Because
terrorist financing heavily depends on ML [2], any AML
system must incorporate SNA to obtain reliable results.
Schwartz [3] proposes a model to find criminal networks using
social network analysis, building upon Borgatti’s SNA-based
key player approach [3]. One drawback of Borgatti's model is
the failure to assign weights to actors and actor-actor
relationships. In the recent past, we have developed algorithms
incorporates Borgatti’s SNA techniques with different weights’
to social and business relationships to help complete missing
links in potential money laundering chains.</p>
      <p>The Financial Action Task Force (FATF) provides a static
risk assessment of ML [4] strategies to examine ML related
predicate crimes and known weaknesses of anti-money
laundering (AML) systems. The Wolfsberg Group, made up of
eleven leading international banks established standards,
guidelines and a discretionary risk model [5] to counter money
laundering. Both FATF and Wolfsberg Group say that
monitoring customers is an essential part of countering money
laundering and suggest that risks can be measured using
metrics such as “Country risk”, “Customer risk”, and “Services
risk”, and leave weights assigned to each of these categories at
the discretion of the evaluating organization. Based on these
guidelines, banks use a quantitative model to evaluate
transactional risk using attributes such as “Customer profile”,
“Product/service profile”, and “Geographic profile”.</p>
      <p>The static risk model developed by Scor [6] accepts ML to
be determined by “Agility” of adopting new rules per
customer, “Complexity” of transactions and the “Secrecy” of
transactional information and customer account” [6], but fails
to assess other factors such as relationship networks, and
dynamically changing factors. Kount [7] developed a dynamic
scoring service to continuously monitor indicators of fraudulent
credit card activity, and alert merchants of approved
transactions that are linked to suspicious purchasing activities,
that usually occur after identity theft. These suspicious
purchases refer are transactions patterns that have never been
witnessed before, such as the purchase of video games by
senior citizen.</p>
      <p>The rest of the paper is organized as follows. Section 2
describes the Money Laundering Evolution Detection
Framework (MLEDF). Section 3 describes the SNA algorithm.
Section 4 describes the dynamic risk model. Section 5
evaluates the performance of the MLEDF and dynamic risk
model using real-life cases. Section 6 concludes the paper.</p>
      <p>II.</p>
    </sec>
    <sec id="sec-2">
      <title>ML EVOLUTION DETECTION FRAMEWORK (MLEDF)</title>
      <p>Fig. 1. Money Laundering Evolution Detection Framework</p>
      <p>First we briefly describe how MLEDF works [8]. Obtaining
data streams from multiple sources listed in the left hand
column of Fig.1, using a complex event processing system.
MLEDF uses four phases where output from one phase is used
by the following phase and shown in the columns of Figure1.</p>
      <p>
        (
        <xref ref-type="bibr" rid="ref1">1</xref>
        ) Collecting Transactional Data: Transaction processors
or data collectors from Automated Clearing House such as
EPN, FEDWIRE, and CHIPS send their data belonging to trade
sectors such as Banking, Stock market, Derivative market, Web
based Services, Trading, Electronic Money, and Money
Brokering. Relevant information is extracted form this data and
used with transaction-independent data such as the economic
status of the country, stock sales trends and the stock values
during the day.
      </p>
      <p>
        (
        <xref ref-type="bibr" rid="ref2">2</xref>
        ) Data Processing: Well-known MLS are identified and
relevant attributes are collected from input data streams and
submitted to our detection algorithms. The extracted data
associated with each MLS pattern assigned to a specific MLS
type using the following: (I) Business Rules: MLS business
rules and red flags associated with each pattern, the rules
associated with specific sector are used by the MLS detection
algorithms to identify the MLS patterns. (II) MLS Template:
Well-known MLS templates will be used during this phase.
Currently, the templates have seven major pattern types with
their different subtype combinations. This acts as a repository
of known MLS. If a new form of MLS is discovered, then it
will be added to this Database. (III) ML Evolution Model:
Determines if the evolution of MLS is within the accepted
trend of our model [8].
      </p>
      <p>
        (
        <xref ref-type="bibr" rid="ref3">3</xref>
        ) Detecting MLS Networks: We use six algorithm (one for
each) to detect Smurfing, Trade, Stock, Derivative, E-Money,
and Dirty Electronic Funds Transfer (Dirty-EFT) schemes.
Each algorithm uses a different method to capture the network
associated with the specific type of MLS and in real-time
output the discovered networks associated with the specific
MLS pattern into a different database. Then, the discovered
networks are reformatted and saved in a single database
referred to as the “Network” Database to facilitate efficient
analysis of the links among MLS networks.
      </p>
      <p>
        (
        <xref ref-type="bibr" rid="ref4">4</xref>
        ) ML Trail Analysis and Evolution Detection: Four
separate algorithms are run to find the “Full-Trails” [8],
“Missing-Trails”, and “Suspicious-Trails” of MLS networks.
“Full-Trail” is a concatenated sequence of related schemes
(MLS) act by itself to transfer money from one MLS to another
until it reaches the final MLS, of which the orchestrator (i.e. the
money launderer) is referred to as the “EndBoss”. Similarly the
orchestrator of the first scheme is referred to as the
“StartBoss”. “Associates” are other people involved in the
sequence of fraud. “Missing-Trail” is a short Full-Trail that
does not exceed have more than three related MLSs. A sample
output from the Full Train Algorithm is given in Table 1,
where a network ID (assigned by our detection algorithm), the
duration of the laundering activity, if the money was withdrawn
after the third transaction, the amount of money and the
detected Start Boss and the detected End Boss are provided.
We assume that the Missing-Trail is a premature Full-Trail
with broken parts and missing links or evidence. A
“Suspicious-Trail” is a combination of discovered Full-Trails
and/or Missing-Trails constructed using algorithms that
incorporate SNA and numerical analysis techniques. The
algorithm “Detection Analysis” determines the evolution of the
“Full-Trail”s such as the change to the number of involved
associates, the changes to the cost of laundering, and changes
to the laundering locations.
      </p>
      <p>III.</p>
      <p>SOCIAL NETWORK ANALYSIS IN MLEDF</p>
      <p>In many cases money launderers intentionally obfuscate the
money trail either by hiding it (for example by increasing the
number of transactions and reducing the transacted amount), or
using an unreported method such as a Hawala [15] (an honor
based exchange system without records). As a solution, we use
a social network among money launderers to link MLS trails
when evidence of linkage is missing among transactions.</p>
      <sec id="sec-2-1">
        <title>A. Using Complex Event Processing in the SNA Module</title>
        <p>The critical question of ML experts is “How fast and how
well can we relate the different events in this universe of
detected MLS?” Using the Complex Event Processing (CEP)
system StreamBase, we developed an algorithm to create
chains of related MLSs where social or professional relations
are used to transfer a fund to the next MLS until it reaches the
final destination where the End Boss withdraws the money. If
we modeled all of the chains as a separately and link them we
run into a scalability issue in associating the multitude of
different events of various MLSs. As a solution, we model each
detected MLS as an event, and have various patterns of events
categorized under six different types of MLS. For example,
Full-Trail algorithm outputs a trail by using the functionality of
CEP of perceiving the MLSs as a set of events. Without the
CEP the MLS should dissolve into the constituent transactions
to be analyzed and linked with other transactions from another
MLS, consumes processing time and resources. The CEP can
link MLSs, perceived as events, using various criterions
without the need to add more complex sub-algorithms for each
criterion. That is, the Full-Trail connects the dots that exist, but
it is harder and slower to connect them without CEP
capabilities. Full-Trail captures the trail in cases where all
evidence are available, whereas the Suspicious-Trail attempts
to construct the path where some edges along the path is
missing.</p>
      </sec>
      <sec id="sec-2-2">
        <title>B. Integrating the “SNA” Module into MLEDF</title>
        <p>The “Suspicious-Trail” module is used to detect
components of an actual “Full-Trail” even if there is a missing
piece of evidence. This module investigates all available trails
(Full-Trail and Missing-Trail) by using our SNA DB that
contains the weights of relationships among MLS participants
in order to determine if two trails are related by considering
some attributes such as the amount of funds involved, location,
affinity of participants, time, and methods used for laundering.
Hence, the “Suspicious-Trail” module uses the “SNA” module
to produce a new trail containing two or more trails that are
related based on SNA even when we have not captured a
transaction joining them or any other evidence. The new trail is
created after making a calculation based on (SNA) results of a
possible relationship between two or more Full-Trails and
Missing-Trails. The generated evolution patterns and strategies
are collected into the “Suspicious-Trail” Database.</p>
        <p>
          The architecture of the social network algorithm is shown
in Figure 2. The SNA module generates and continuously
updates two databases as outputs. The “SuspectWeight”
database contains the weight of all relations detected in the
MLEDF and the “Relations” database containing the time and
the record of all detected relations among pairs in MLEDF as
shown in the bottom of Figure 2. The relations we capture are:
(
          <xref ref-type="bibr" rid="ref1">1</xref>
          ) UniqueFullTrailBosses creating “StartBoss”–“EndBoss”
pairs of “Full-Trail”s. (
          <xref ref-type="bibr" rid="ref2">2</xref>
          ) UniqueFullTrailAssociates creating
“Asscoiate”-“Asscoiate” pairs of “Full-Trail”s. (
          <xref ref-type="bibr" rid="ref3">3</xref>
          )
UniqueMissingTrailAssociates createing
“Asscoiate”“Asscoiate” pairs of “Missing-Trail”s. (
          <xref ref-type="bibr" rid="ref4">4</xref>
          ) SchemaBosses
creating Hashes for “StartBoss”-“EndBoss” relations. (
          <xref ref-type="bibr" rid="ref5">5</xref>
          )
SchemaAssociateBoss creating Hashes for all detected
“BossAssociate” relations. (
          <xref ref-type="bibr" rid="ref6">6</xref>
          ) SchemaAssociate creates Hashes for
all detected “Associate-Associate” relationships. This hash
represents the combinations of relationships among the
associates of the same MLS, even if they do not
interact/transact with each other directly. (
          <xref ref-type="bibr" rid="ref7">7</xref>
          ) Family creating
“Family” relation between lineage-wise related pairs. (
          <xref ref-type="bibr" rid="ref8">8</xref>
          )
Business creating business-wise related pairs. Each such
relationship is shown in Figure 2. We compute these
relationships and assign weights to them as shown in
Algorithm 1 describe in Table II.
The relationship weights as assigned so that higher weight
indicates more possible hidden interactions. Weights are
calculated by adding parameters for each of the corresponding
events as follows:
1. Each detected “MLS” weights of 10 will be added to
start/end boss couple, 5 for each boss/associate
combination, and 1 for each non-repeating
associate/associate combination.
2. Each detected “Missing-Trail”, 15 will be added to each
associate non-repeating combination.
3. Each detected “Full-Trail” add 20 to each associate
combination and 25 to the start and end boss.
        </p>
        <p>Other strong relationships are also counted where “Family”
ties will add 250 to the couple, and each “Business”
relationship will add 250 to the couple. We chose the weights
and, verified them in a limited engagement with a trusted third
party (see Section V), but can be changed in Algorithm 1.</p>
        <p>In the SNA Algorithm given in Table II, steps 1 and 2
define the hash function, and input and DBs constants
associated with the different weights and the hash functions.
Steps 3 and 4 create hashes for “Boss-Boss”, “Boss-Associate”,
and “Associate-Associate” of MLSs. Steps 5 and 6 create the
same hashes for Full-Trails. Steps 7 and 8 create hashes for
Missing-Trails and special relations (of family and business).
Step 9 computes the WeightOutput of a hash HRel. Sample
Suspect Weights obtained from Algorithm 1 is shown in Table
IV. This corresponds to Relationships given in Table III.</p>
        <p>Existing AML systems do not relate different products
types, entities, and business lines involved in different
combinations of complicated ML schemes. Industry specific
AML systems use industry specific static risk models and
therefore do not capture known dynamics of MLS evolutions.
Countering ML and other forms of fraud requires
industrywide risk analysis method to where the risk score is updated
dynamically and include transactional behavior related to the
ML, such as the social relations and past associations with
money laundering. Therefore, we create a dynamic risk model
that incorporates the static attributes used by others, such as the
senders and recipient’s static profiles and dynamic social
connection attributes of the transactions that we capture in our
MLEDF system.</p>
        <sec id="sec-2-2-1">
          <title>A. The Static Risk Model of Bnak Secrecy Act</title>
          <p>The Currency and Financial Transactions Reporting Act
(CFTRA) of 1970 later amended to counter money laundering
and financial crimes [11, 12, 13] and again amended by Title
III of the PATRIOT Act of 2001 and other legislations, and is
now commonly referred to as the "Bank Security Act" (BSA)
mandates banks to monitor transactions and maintain records
of initial and periodic risk scores for customers. Their risk
model identify and analyze specific “products and services”,
“customers and entities”, and “geographical locations” and
categorize them as “high", "medium", and "low", and add the
risk rating of all categories to obtain the overall accumulative
risk score. We enhanced the BSA inspired static risk with
aggregated static risk to reflect changing dynamics of ML and
its consequences on the static risk calculation shown in Figure
3. The risk rates assigned in Figure 3 are obtained from [9],
with suggested enhancements in the upper right hand box.
Definition 1 captures these attributes and scores.</p>
          <p>Definition 1 [Local Static Risk Score (LSRS) and Risk
Categories]: The Local Static Risk Score is the sum of the
following attributes and their assignable integer values;
Account Risk Range:[-5,+10], Location Risk Range: [-1,+10]
Business Risk Range: [-15,+20], Product Risk Range: [0,+5]</p>
          <p>Here Account Risk is the sum of Customer Risk [-5, +10]
and Tax ID Risk [+5]. The Location Risk is the Sum of Primary
Location Risk [+2]. The sum of the Risks of Non Primary
Locations, where each Non Primary Risk is a value in the
Range [-1,+10]. The Business Risk is defined as the sum of
Business Primary Risk [-3, +20] and Business Nature Risk [-15,
+20]. The Product Risk is the sum of Debit Activity Risk [0, +5]
and Credit Activity Risk: [0, +5].</p>
          <p>The BSA risk score is the sum of the component risk scores
of Account Risk, Location Risk, Business Risk and Product
Risk. Each of these components risks are also sums of further
sub components as specified in Definition 1. Possible
computed value for a customer is an integer value for between
23 and +20. The details of risks used in Definition1 are as
follows. The Account Risk is the Risk due to customer’s
reputation and a risk assigned due to providing / not providing
a TAX ID. The Locations Risk is the sum of having multiple
business Locations, and the risk associated with the Primary
business Location. The Business risk is the sum of the risk due
to the Principal Owner and the risk associated with the Nature
of the Business. The financial product risk is associated with
the debit and credit activities. We amended the factors of
“product risk” in the BSA model to include a risk factor of the
derivative market activity. We also reduced the risk weight of
three factors in the “business risk” of BSA model from the
original value of “+30” to the new value of “+20”, as the total
risk score of “30” is the cut-off for an alert to the management
of the financial institution. The reduction of the weight of the
three factors to “+20” is necessary to lower the aggressiveness
of the risk model. Definition 2 categorize these risks as Low,
Medium, High and Extreme and are again an extension of the
values in [9].</p>
          <p>Definition 2 [Categorizing Local Static Risk Scores]: Local
Static Risk Scores (LSRS) are categorized as low, medium,
high and extremely high based on range of the totally
calculated score: Low [-23, 4], Moderate [+5, +14], High [+15,
+30], Extreme Risk [+31, +153].</p>
        </sec>
        <sec id="sec-2-2-2">
          <title>B. Accumative Static Risk Score</title>
          <p>To compute the risk of transacting customers, in addition to
Static Local Risk Score (LSRS), risk of recent transactions
need to be taken into account. We propose a simplified
mechanism of exchanging aggregate risk scores assigned to
customer transactions, because a running average may not
expose all the data of all transactions and therefore may not
violate privacy. Formally, let TRN(O,R), be a transaction with
originator O and recipient R, and let TRNA ≡ &lt;TRNA1(x1,y1),
TRNA2(x2,y2),, …… , TRNAn(xn,yn)&gt;, listed in newest to oldest
transaction order represent the last n transactions of A. Let
Partneri(A,TRNAi(xi,yi)) represent the entity other than A and
&lt;LSRS(Partner1(A,TRNAi(xi,yi)))&gt;be the LSRS values of
partners of A in the last n transactions. Then recursively define
the Exponential Moving Average (EMA) risk as: EMA(i) =
LSRS(Partneri(A,TRNAi(xi,yi)))* k + EMA(i-1) * (1 – k) where
k = 2/(n+1) .</p>
          <p>Definition 3 [Receiver’s/Originator’s Average Risk and
Variance]: These averages are calculated by the bank that
holds the account of entity A, it is done by calculating the
exponential moving average of the LSRS of the last n
transacting partners of A,
Let EMAi be LSRS(Partner1(A,TRNA1(xi,yi)))* k + EMA(i-1) *
(1 – k) where k = 2/(n+1), and where A=xi for all i&lt;n.
Let VarA be LSRSA– Average(LSRS(Partner1(A,TRNA1(x1,y1)))),
…, LSRS(Partnern(A,TRNAin(xn,yn))).</p>
          <p>As with the Average, VARAi computes the receiver’s and
originators risk based on the value of
Partneri(A,TRANAi(xi,yi)). When Partneri(A,TRANAi(xi,yi)) =
A= Receiver for all i&lt;n. Then EMAi computes the receiver’s
risk and When Partneri(A,TRANAi(xi,yi)) = A= Originator for
all i&lt;n. Then EMAi computes the originator’s risk. The RA/OA
parameters assess the risks associated with the
participation/involvement of an entity in the ML, by analyzing
the affinity/role in the money-flow of a laundering process. The
RA and OA used to calculate/keep a record of the historical
activity and the divergence in pattern of receiving or sending
funds. The pattern are used as an indicator for assessing a risk
penalty, comparing the current RA/OA value with the value of
90 days and 180 days ago (RA/OA) indicate the transactional
tendency of the entity.</p>
          <p>We assign a penalty and reward system for entities so that
an entity that continuously transacts in high and increasingly
risky pattern is subject to penalties for having an increased
LSRS, and vice versa. Thus our penalty and rewards system
self-adjusts and the leverage provided by this self-adjustment
avoid maintaining the risk value of an entity at a static level.
The penalty can be set upon the needs of the financial
institution and the regulations of the country, although optimal
levels are shown in the formula below. The optimum
penalty/reward are produced to allow entities to retain their old
static risk levels in between one and n transactions. The criteria
defined below indicate that if the aggregate risk sores is higher
than 90 days ago which is higher than the same value 180 days
ago this entity’s transacting risk is on the increase.</p>
          <p>Definition 4 [Penalties and Rewards]: We define RA0M,
RA3M, RA6M, OA0M, OA3M, and OA6M to be respectively the
current, three months, and six months old values of RA and OA
value, for any entity. Let RA-Inc, RA-Dec, OA-Inc and OA-Dec
be defined as (RA6M&lt;RA3M&lt;RA0M), (RA6M&gt;RA3M&gt;RA0M),
(OA6M&lt;OA3M&lt;OA0M), and (OA6M&gt;OA3M&gt;OA0M) and Static
Risk Penalty and Reward (SRPR) as:
(RA-Inc)/\(OA-Inc)/\(RA&gt;LSRS)/\(LSRS&gt;35)/\(RV&gt;5)/\(OV&gt;5)=&gt; SRPR=+5
(RA-Inc)/\(OA-Dec)/\(RA&gt;LSRS)/\(LSRS&gt;35)/\(RV&gt;5)/\(OV&gt;5)=&gt; SRPR=+3
(RA-Dec)/\(OA-Inc)/\(RA&gt;LSRS)/\(LSRS&gt;35)/\(RV&gt;5)/\(OV&gt;5)=&gt; SRPR=+3
(RA-Dec)/\(OA-Dec)/\(RA&gt;LSRS)/\(LSRS&gt;35)/\(RV&gt;5)/\(OV&gt;5)=&gt; SRPR=+2
(RA-Dec)/\(OA-Dec)/\(RA&gt;LSRS)/\(LSRS&gt;35)/\(RV&lt;5)/\(OV&lt;5)=&gt; SRPR=-2
(RA-Dec)/\(OA-Dec)/\(RA&lt;LSRS)/\(LSRS&gt;35)/\(RV&gt;5)/\(OV&gt;5)=&gt; SRPR=-3
((RA-Any)/\/(OA-Any))/\ (RA&lt;LSRS) =&gt;SRPR=0</p>
          <p>
            A detailed rationale for this definition is described in
[14]. The LSRS will be calculated every time the transaction
occurs. For example, the first line of Definition 4 says that if
conditions (
            <xref ref-type="bibr" rid="ref1">1</xref>
            ) “RA6&lt;RA3&lt;RA”, (
            <xref ref-type="bibr" rid="ref2">2</xref>
            ) OA6&lt;OA3&lt;OA, (
            <xref ref-type="bibr" rid="ref3">3</xref>
            )
RA≥LSRS and (
            <xref ref-type="bibr" rid="ref4">4</xref>
            ) RV&gt;OV&gt;0 are met, the SRP of “+5” will be
imposed. The RA is the primary factor that LSRS depends
upon on to determine the penalty value due to the fact that
receiving the funds is where the money laundering fraud starts.
The penalty and reward point system will have the upper and
lower bounds, in order to maintain the LSRS within its
boundaries so that their accumulation will have a fix point (risk
saturation point) in its decreasing or increasing trend. There is
no need to apply the penalty on an entity that is in maximum
risk levels of LSRS, as the purpose is to provide the transacting
entity with the ability to reduce the risk.
          </p>
          <p>Definition 5 [Accumulative Static Risk Score (ASRS)]: of an
entity is the sum of the local static risk score and static risk
penalty and reward. Thus, ASRS =LSRS + SRPR.</p>
          <p>C. Accumulative Dynamic Risk Score</p>
          <p>
            The dynamics of none-static risk scoring was designed
considering the following criteria: (
            <xref ref-type="bibr" rid="ref1">1</xref>
            ) Continuous scoring: The
score is calculated per every transaction. (
            <xref ref-type="bibr" rid="ref2">2</xref>
            ) Automatic scoring:
Risk computation does not require the involvement of an
expert. (
            <xref ref-type="bibr" rid="ref3">3</xref>
            ) Correlation of past transactions: Risk score
correlate transactions with current one.
          </p>
          <p>
            We have developed an algorithm to assigning weights to
relations, the so-called Dynamic Relation Extract Algorithm
(DREA) [14] that searches the SNA DB “SuspectWeight” for
the detected past n ML activities of the entity A. The algorithm
is similar to the algorithm used in the “SNA” module of
MLEDF as explained in Section 2. Using this algorithm, we
assign a risk weight for entity A, for each detected ML activity
in the SNA DB “SuspectWeight” by adding parameters for
each of the corresponding events resulting in the accumulative
risk weight as follows: (
            <xref ref-type="bibr" rid="ref1">1</xref>
            ) For each detected MLS, add 5 to
start/end boss couple, 2 for each boss/associate combination,
and 1 for each associate/associate non-repeating combination.
For each Missing-Trail add 3 to each associate non-repeating
combination. The Full-Trails adds 3 to each associate
combination and 10 to the start/end boss. Again these are our
sample values that can be changed by any institutions. We omit
an algorithmic presentation due to lack of space.
We also compute a risk score named the Self Adjusting
Dynamic Risk Score (SDRS) that assigns a risk weight to the
transactional history of transacting entity (say) A in the
database “Suspect-Weight” in the DREA algorithm that we
refer to as DREA(Entity A)].
          </p>
          <p>Definition 6 [Receivers’ / Originators’ Dynamic Risk Score
(RDRS/ODRS)]: Calculates the aggregate risk weight, based
on the relations history of the last n entities (R1,...,Rn) funds
receiving from, and the last n entities (O1,...,On) funds
originating to the entity A. The average weight of receiving
/originating entities is obtained by calculating the average of
DREA(R1), .. ,DREA(Rn ) and DREA(O1), .. ,DREA(On ). We
produce ODRS and RDRS.</p>
          <p>Definition 7 [Accumulative Dynamic Risk Score (ADRS)]:
Of an entity is the sum of SDRS, RDRS and ODRS. That is
ADRS = SDR+ RDR+ODR.</p>
          <p>D. Accumlative Transaction Scoring Based on Dyanmic Risk</p>
          <p>Static and dynamic risks are correlated to the analytics of
transaction scoring, in order to identify transactions with
highrisk score pertaining to ML, and to prevent transaction
sequences from being executed. The correlations used in the
dynamic risk scoring can be used to detect and track
transactions belong of ML schemes.</p>
          <p>Definition 8 [Accumulative Transaction Score (ATS)]:
The ATS is calculated as the average risk of (ADRS, ASRS,
LSRS) of the two transacting entities.</p>
          <p>Receiver-ATS=∑Receiver(ADRS,ASRS),
Originator-ATS = ∑ Originator (ADRS, ASRS).</p>
          <p>ATS = AVG (Receiver-ATS , Originator-ATS).
Definition 9: Comprehensive Transaction Data (CTD): The
triple (LSRS, ASRS, ADRS) is said to be the comprehensive
transaction data (CTD).</p>
          <p>Thus, our comprehensive dynamic risk model consists of two
parts, computing the static risk, as by amending the BSA risk
model [9] and computing the dynamic risk per every
transaction. Figure 4 summarizes the two aspects of our risk
model and the data used compute the individual components.
As the figure shows, the static risk score is summarized in the
accumulative static risk score (an enhancement of the BSA
model) and the Dynamic risk score that takes the originators
and recipients running averages of static risk scores and other
properties of the transactions and SNA information to compute
a dynamic risk value per each transaction. As stated, this value
is fed back to the running averages and variances of this static
risk scores. This latter step requires the financial institutions to
share such risk estimates along with transactions.</p>
          <p>V.</p>
          <p>VALIDATION</p>
          <p>We used sanitized real-life cases to test and validate the
dynamic risk model with MLEDF and transaction scoring. Our
case studies are based on data provided from an organization
we refer as Trusted Third Party (TTP), which is authorized to
collect information and track records of financial exchanges.
A. Experimental Evaluation and Valiation of MLEDF</p>
          <p>We introduced a three phase testing prototype to examine
MLEDF and detection algorithms. All three phases focused on
testing and validating the components of MLS, Full-Trails, and
Suspicious-Trails. The first phase focused on testing all
components and the other tests focus on Full-Trail and
Suspicious-Trail components.</p>
          <p>Test without noise: This test is designed to test every
module of MLEDF, including detection algorithms and trail
analysis modules. These tests evaluate the false positive rates
(FPR) and false negative rates (FNR) by comparing the results
of the test with the data feed that contains the patterns of
single MLS, pair of MLSs, and Full-Trails. The desired result
was to have a list of the validation result identical to the list in
the data feed. We tested the efficiency to keep up with the
speed of the data feed by using the time window feature in the
StreamBase [10]. By setting the time window to glide over
only one event at a time tick in the StreamBase system, we
made the detection algorithms to run at the normal speed of
one event at one time tick. By design, an algorithm that cannot
attain the speed of event production will not be able to capture
MLS events or the Full-Trail, thereby generating false
negatives.</p>
          <p>Each of the six detection algorithms were tested with their
own data feeds in order to verify that we were able to detect a
single event MLS without false positives and false negatives.
The algorithm-specific dataset feed was generated using the
built in feed generator working with our pattern specific event
generator. Afterwards, we tested the “Missing-Trail” by
feeding linked pairs of MLSs into the MLEDF. The
linked/related pairs are randomly selected from the set of six
types of MLS. As mentioned, any pair of linked MLS will
make it to “Missing-Trail” and not into “Full-Trail”, due to the
required depth. Finally, we tested the detection and evolution
of “Full-Trail”s by feeding trails generated from various
laundering strategies used in our sample real-life cases.</p>
          <p>The process of creating the “Full-Trail” started with
creating an MLS type out of the six MLS types of Smurfing,
Trading, DirtyEFT, Stock, Derivative, E-Money. Once the
selection of first MLS is made, we create ta series of linked
MLS based on conditions such as geography, amount of
money, time, complexity of the schema and difficulty of
tracking. The trails were created using different criteria and
randomizing them using a normal distribution. We created the
Full-Trail feeds using the generator to not exceed 10 levels of
depth of linked MLSs. These trails were either a variant or a
subsection of one of the real-life cases that were similar in
terms of complexity and participants.</p>
          <p>At the normal speed of one event at one time tick of the
CEP system, the test result in zero false positive rates and false
negative rates. It is highly improbable to get a false positive
trail due to the business rules that define them, and due to the
accuracy and granular level of linking transactions. We did not
get any false positive rate (FPR) or false negative rate (FNR) in
the MLS tests due to the synthetic nature of the data. When we
increased the speed of the data generated to 10 times and 100
times the normal speed, we observed a FPR and FNR in the
objects detected in the Full-Trail algorithms. Increasing the
speed of processing did not produce FPR and NFR for a single
MLS, but it produced FPR and FNR for MLS pairs at speeds
that were multiples of 100s. The term “object” in this graph
refers to the three different patterns of single MLS, pair MLS,
and Full-Trail in the proprietary test of the specific object
(Object in the first pattern tests to the first pattern single MLS,
in the second to MLS pair, in the third to Full-Trail). The
values of FRP and FNR reflect the number of falsely detected
objects.</p>
          <p>Test with subtle noise: This is the most relevant accuracy
test of our detection algorithms. The goal of this test was to
mislead the detection algorithms by generating false positives
and false negatives synthetic data. The test had three separate
phases: injecting the scheme participants, injecting subtle
transactions, and inserting similar MLSs. A subtle transaction
is a transaction with ±5% of an actual transaction amount in a
MLS. A similar MLS is identical to a real-life MLS with the
same set of participants but with the MLS value is ±10% of the
laundered amount of the actual MLS. The injection speed was
set to normal processing speed, 10 times faster, and 100 times
faster. The test of injecting transactions and MLSs is setup
considering each MLS type. For example, in the test of
smurfing, we created only smurfing MLS and smurfing
transactions that can extend vertically up to 20 levels of depth
and horizontally to 30 levels of depth. When we were
generating the MLSs our measures did vary based upon the
MLS. We did not use artificially created none-real life cases.
For example, we did not use a smurfing MLS with 100 levels
deep, as that is uncommon and impractical to launder money.
We also did not inject other types of MLSs into the injection
test of a specific MLS. However, in the Full-Trail test, we
injected all types of MLS because by design, a Full-Trail is
required to have different types of MLS under the same
FullTrail.</p>
          <p>The test produced low FNR and low FPR for transaction
and MLS injection when the phases were executed at normal
processing speed. Those rates increased in the phases when
tests were executed at faster processing speed. One way to
imitate the data rate of real production environment is to run
the CEP tests at a faster rate, thereby overloading the system
with processing and analytics while attempting to keep pace
with the data stream. The goal was to evaluate the effectiveness
of “Full-Trail” detection when the system absorbs data at a
higher rate while performing the analysis. Due to the design
methodology of detection algorithms and the complexity of the
business rules of MLS detection, their false detection rates
stayed at low levels (less than 5%) even with injection similar
transactions and MLSs, at a higher data-feed speed (1000% and
10000% speed).</p>
          <p>
            Meeting the design principles, the “Full-Trail” and
“Suspicious-Trail” results remained at low rates for both false
positive and false negative. Therefore, all the subtle single
MLS created with injected data ended in the “Missing-Trail”,
where they did not exceed the depth of 3 consecutive MLSs.
Some reasons for this success in trail analysis and avoiding any
negative impact are (
            <xref ref-type="bibr" rid="ref1">1</xref>
            ) MLEDF is designed in a strict and
granular method, especially for matching MLSs within trails,
(
            <xref ref-type="bibr" rid="ref2">2</xref>
            ) SNA is used in the trail analysis algorithms, (
            <xref ref-type="bibr" rid="ref3">3</xref>
            ) Adopted
the criterion to follow the direction of the flow of the
laundered-money. MLS is not expected to terminate with funds
remaining in the account. The money must flow in some
direction in order to be laundered, or must be withdrawn by the
launderer. The Figures 5, 6 and 7 show the results of the
number (quantity) of the transactions resulted in false positive
and false negative, as explained in the previous paragraph. The
figures show the number of FP and FN patterns of each phase
from the three injection phases of the Test II, along with the
results from running the test at different speed (1000% and
10000% speed).
          </p>
          <p>
            Test with longer synthetic full-trails: This was the hardest
level of performance testing of the system and accuracy-testing
of the detection algorithms we carried out. In this test, the
dataset was permutated over a repository of different real-life
cases. Afterwards, the dataset was combined with randomized
MLS to generate deep vertical levels of “Full-Trail”s and
“Suspicious-Trail”s. The randomization followed the same
principles used in Test II’s injection testing. The test was
designed to assess the performance of MLEDF in capturing
real-life data and analyzing them on the fly. The desired test
result was to generate low FPR and FNR. The test module
generated all synthetic data from real-life cases and tests were
similar to real-life scenarios, considering that there are limited
ways to manipulate a MLS. The test program functions as
follows: (
            <xref ref-type="bibr" rid="ref1">1</xref>
            ) Set a trail depth. The program enters a loop and
builds a trail by choosing a first scheme from of each MLS
type at random, as it was described in Test I in building the
Full-Trails. (
            <xref ref-type="bibr" rid="ref2">2</xref>
            ) The loop continues by creating an MLS that can
be linked by funds, time, location and complexity to the current
MLS. We repeated the step above with the exception of not
creating any Smurfing MLS for the rest of the levels. (
            <xref ref-type="bibr" rid="ref3">3</xref>
            ) The
permutation continues until the system reached the last level,
where we always choose an MLS of type DirtyEFT with a
withdrawal in order to generate the trail termination point, as
by definition a trail will end with the withdrawal of money. (
            <xref ref-type="bibr" rid="ref4">4</xref>
            )
The test were repeated the process of trail generation forever at
the maximum possible speed. (
            <xref ref-type="bibr" rid="ref5">5</xref>
            ) The testing module saved the
arrival time of the last DirtyEFT and subtracted that from the
build times of the trail, thereby obtaining Milliseconds
difference in trail processing times.
          </p>
          <p>Our data was generated for worst-case scenarios to ensure
that they are more complex and the performance was evaluated
only in most resource consuming cases. Displayed results
represent the performance of data generated without any
repetitive bosses or associates. Hence, the dataset consumes a
significant number of resources.</p>
          <p>1.0%$
0.0%$
10&amp;Depth$
20&amp;Depth$
30&amp;Depth$</p>
          <p>
            Test Methodology: We introduced a four phase risk model
testing prototype to examine the three different versions of
static risk model, and the dynamic risk model: (
            <xref ref-type="bibr" rid="ref1">1</xref>
            ) T1: Using
standard average instead of the exponential average in
calculating static risk. (
            <xref ref-type="bibr" rid="ref2">2</xref>
            ) T2: Using exponential average, but
applying only penalty and no reward in calculating static risk.
(
            <xref ref-type="bibr" rid="ref3">3</xref>
            ) T3: Using exponential average, apply both penalty and
reward in calculating static risk. (
            <xref ref-type="bibr" rid="ref4">4</xref>
            ) T4: Using detected
schemes, from the output of MLEDF, to produce dynamic risk
scores.
          </p>
          <p>
            Injected Data Phases: Four different types of transactions
were injected in each of test phases with LSRS value of (
            <xref ref-type="bibr" rid="ref10">10,
20, 30, 40</xref>
            ) in the transactions of each test.
          </p>
          <p>
            Test Goals: (
            <xref ref-type="bibr" rid="ref1">1</xref>
            ) Produce risk levels above certain threshold
for continuously riskily transacting entities. (
            <xref ref-type="bibr" rid="ref2">2</xref>
            ) Effectiveness
when certain patterns (all high risk or all low risk) were
injected, (A) Does the ADRS/ASRS saturates at some
fixedpoint level? (B) False Positive (FP): ADRS/ASRS continue to
grow towards the high risk level of the continuously injected
data (C) False Negative (FN): ADRS/ASRS deviates towards
the low risk level of the continuously injected data (D)
Maintain a desired risk level for bad entities even if they
deliberately transact with good entities, in order to lower their
risk profile.
          </p>
          <p>Results: The dynamic risk model (T4) produces FP for
transactions of none-MLEDF entities. The rate was less than
5% and that was satisfactory considering the large amount of
transactions. This is advantageous compared with risk models
that do not assess the risk of being involved in MLS,
considering the factors of increasing risk scores of MLEDF
entities.</p>
          <p>Validation Statement: We used the StreamBase Studio [10]
platform in each test of (T1, T2, T3, T4) and with each of the
four data injection phases (by only injecting entities did not
exist in MLEDF). The false negative rate was below 1% in
phase 1 of all tests, and 0% in remaining three phases of data
injection for all tests. The false positive rate was below 5% for
T4, and lesser for other the three static tests (T1, T2, T3). In
test T4 and with each of the four data injection phases by
injecting entities did exist in MLEDF. The false negative rate
for T4 (When only injecting entities that are already detected
by MLEDF) is the highest at 11% when entities with high static
risk (of LSRS 30) are injected in phase 4, then at 9% in phase 1
when high static risk score (of LSRS 25) are injected, then at
8% in phase 3, and finally at 3% in phase2 when low risk score
(of LSRS 10) is injected. The false negative rate is 0% in all
phases of test T4. Table V summarizes our findings. Figure 9
shows the false positive and false negative rates for injecting
MLS’s with 10, 20, 25 and 30 LSRS values.</p>
          <p>We implemented a multiphase, multilevel, and
multicomponent methodology to detect evolving money-laundering
schemes using known methods, influenced by economic
factors. We have created a framework to detect the evolution of
MLS and implemented a system to include SNA for detecting
and linking related ML networks. This linkage will function
properly even when all evidence is unavailable. We defined the
choreographies that could be used to detect the evolution of the
sophisticated MLS. We have shown how to detect and capture
the evolving and complex trails of MLS using SB.</p>
          <p>We enhanced the BSA inspired static risk with aggregated
static risk, to reflect the changing dynamics of the ML and its
consequences on the risk calculation. Our risk model factors in
the initial account-opening risk as well as subsequent
transactional risks, and it presents a risk score that is valid
within and outside the boundaries of a single financial
institution. We extended the static risk model to develop a
MLEDF-dependent risk modeling, in order to produce a
comprehensive ML risk modeling in combination with the
aggregated static risk model. The aggregated static risk will be
completed with integration of the MLEDF-dependent risk
modeling, which captures the hidden, and dynamic, relations
among none-transacted entities. Such a risk model is used to
create a valid and accurate transaction scoring system to be
used in a ML prevention system.</p>
        </sec>
      </sec>
    </sec>
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