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<article xmlns:xlink="http://www.w3.org/1999/xlink">
  <front>
    <journal-meta>
      <journal-title-group>
        <journal-title>2023.
VLDB Journal 32 (2023) 905-936. URL: https://doi. Available at: https://github.com/yoheinakajima/b
org/10.1007/s00778</journal-title>
      </journal-title-group>
    </journal-meta>
    <article-meta>
      <article-id pub-id-type="doi">10.1016/j.diin.2015.07.004</article-id>
      <title-group>
        <article-title>ChatGPT as a Copilot for Investigating Digital Evidence</article-title>
      </title-group>
      <contrib-group>
        <contrib contrib-type="author">
          <string-name>Hans Henseler</string-name>
          <xref ref-type="aff" rid="aff0">0</xref>
          <xref ref-type="aff" rid="aff1">1</xref>
        </contrib>
        <contrib contrib-type="author">
          <string-name>Harm van Beek</string-name>
          <xref ref-type="aff" rid="aff0">0</xref>
        </contrib>
        <aff id="aff0">
          <label>0</label>
          <institution>Netherlands Forensic Institute</institution>
        </aff>
        <aff id="aff1">
          <label>1</label>
          <institution>University of Applied Sciences Leiden</institution>
          ,
          <country country="NL">The Netherlands</country>
        </aff>
      </contrib-group>
      <pub-date>
        <year>2020</year>
      </pub-date>
      <volume>2484</volume>
      <fpage>5</fpage>
      <lpage>7</lpage>
      <abstract>
        <p>In today's technology-driven legal landscape, practitioners must continually adapt to new tools and methods that aid not only in addressing cybercrime but also in managing traditional crimes with digital components. This paper explores the potential of advanced AI-powered solutions, such as ChatGPT, in enhancing the capabilities of investigators in various aspects of their investigations. We delve into three specific applications pertinent to legal professionals: (1) writing structured queries utilizing natural language and trace models, (2) summarizing, evaluating, and visualizing electronic communications, and (3) analysing search results. Our findings demonstrate that once ChatGPT is proficient in the query language and data model of the system containing the digital evidence, it holds significant promise in assisting legal professionals in conducting efective investigations.</p>
      </abstract>
      <kwd-group>
        <kwd>eol&gt;digital forensics</kwd>
        <kwd>eDiscovery</kwd>
        <kwd>large language models</kwd>
        <kwd>natural language processing</kwd>
        <kwd>deep learning</kwd>
        <kwd>chatgpt</kwd>
        <kwd>gpt-4</kwd>
      </kwd-group>
    </article-meta>
  </front>
  <body>
    <sec id="sec-1">
      <title>-</title>
      <p>Deep learning is a subset of machine learning that
focuses on artificial neural networks with multiple layers.
These networks can automatically learn representations
from raw data and have demonstrated significant success
in various domains, including computer vision, natural
language processing, and speech recognition [4].</p>
      <p>Large language models, such as GPT-3 [5], are a
spe</p>
    </sec>
    <sec id="sec-2">
      <title>1. Introduction</title>
      <p>The legal profession is witnessing a significant surge
in the adoption of artificial intelligence (AI) tools, with
ChatGPT emerging as a prominent development since
November 2022 [1]. Powered by OpenAI’s advanced
large language model, ChatGPT ofers a natural and
engaging conversational interface on an extensive array
of topics encountered during its training. ChatGPT’s
web application provides users with access to various
models, including the Default GPT-3.5 turbo (a refined
and superior version of GPT-3), Legacy GPT-3.5 (the
preceding ChatGPT model), and GPT-4 (the most
sophisticated model, exclusively accessible to ChatGPT Plus
subscribers). The experiments discussed in this paper
employ the ChatGPT/GPT-4 model, which showcases its
potential applications in the domain of digital evidence
investigation.</p>
      <p>ChatGPT has been fine-tuned with Reinforcement
Learning from Human Feedback (RLHF), e.g., human
reviewers have trained the model to be “helpful, honest
and harmless”, i.e., to not use undesirable language
(violent, sexist, racist, etc.) in conversations. Also, in some
cases reviewers were asked to write example responses
for a chatbot. ChatGPT has learned what useful answers
are, so that conversations flow smoothly. Employing
people to review thousands of prompts is costly and seems
to be one of ChatGPT’s key success factors.</p>
      <p>ChatGPT and large language models (LLMs) in general
are often seen as statistical machines that have learned to
predict the next word based on the sequence of preceding
words [2]. The word ‘statistical machine’ might be
misleading since there seems to be much more to a large
language model then simply predicting the next word. For
instance, Shanahan [3] talks about what LLMs actually
do, how they compare to humans and about unexpected
emerging behaviour. A more accurate description could
be that ChatGPT has learned an algorithm to predict the
next word.</p>
      <p>Nonetheless, ChatGPT is certainly not flawless. It
makes mistakes and sometimes hallucinates facts which
is considered a dangerous aspect. However, when used
as an assistant and when properly instructed, it can be a
smart student that is able to help digital forensic experts
more eficiently and efectively investigate cases with
digital evidence it has never seen before.</p>
      <p>In this paper we describe the rise of ChatGPT followed
by prospective applications in digital investigation and
an overview of related work. We then present empirical
results from three experiments, followed by an
evaluation, discussion and conclusions.
2. The rise of ChatGPT
vast amounts of text data, enabling them to generate LegalAIIA2, e.g., network-based filtering for large email
human-like text and perform various language-related collections [16], semantic search in eDiscovery [17] and
tasks with high accuracy. The development of large lan- technology assisted analysis of timeline and connections
guage models has significantly advanced the capabilities in digital forensic investigations [18]. The experiments
of AI systems, allowing them to generate text in a more in this paper will touch on similar topics but are focused
context-aware and coherent manner. on the application of ChatGPT. We discuss the relevance</p>
      <p>The GPT-4 architecture that is underlying ChatGPT of three specific tasks in digital evidence investigations.
is one such large language model. It is trained using a
diverse dataset, including books, articles and web pages, 3.1. Writing structured queries utilizing
enabling it to generate contextually relevant responses
natural language and trace models
to text inputs. Its architecture allows it to capture
longrange dependencies and generate coherent responses One of the primary challenges faced by investigators
across a wide range of topics. is eficiently querying vast amounts of digital evidence.</p>
      <p>Large language models have found success in several Typically, investigators need to have a thorough
underapplications outside the field of digital evidence inves- standing of forensic data models and query languages,
tigations. For instance, they have been used to gener- such as SQL, to retrieve relevant information from digital
ate coherent and context-aware text for creative writ- evidence. This can be a time-consuming and complex
proing [6, 7], assist with code generation and programming cess, especially for investigators with limited technical
tasks [8], and provide relevant answers to questions in expertise in this area.
customer support scenarios [9, 10]. These models have The ability to convert natural language queries into
also demonstrated capabilities in tasks such as machine structured queries can significantly streamline the
intranslation [11] and summarization [12], showcasing vestigative process. By allowing investigators to simply
their versatility and potential across various domains. describe their query in everyday language, large language</p>
      <p>Finally we note that ChatGPT is also heavily debated models can generate the corresponding structured query
in the field of law and legal services. For instance, in a that retrieves the relevant information. This not only
panel discussion hosted by the Northwestern Law and saves time and efort but also reduces the potential for
Technology Initiative and the High Tech Law Society[13] errors caused by incorrect or incomplete queries.
panelists discussed the potential and limitations that
ChatGPT has for various legal tasks, such as drafting 3.2. Summarize, evaluate and visualize
contracts and briefs, providing legal advice, and
automating legal reasoning. A few months later ChatGPT/GPT-4 chat messages
passed the Uniform Bar Examination with a score of Chat conversations often play a critical role in digital
297, which is higher than the passing threshold of any evidence investigations, as they can provide valuable
jurisdiction and nears the 90th percentile of human test- insights into the activities, intentions, and relationships
takers [14, 15]. The consensus in the field of law and of individuals involved in illicit activities. Analyzing
legal services seems to be that ChatGPT is a powerful chat conversations can be a labor-intensive and
timetool that could be transformative, but also requires care- consuming task, particularly when dealing with lengthy
ful evaluation and regulation to ensure its responsible or complex chat logs involving multiple participants.
use. Text summarization is an active research field since the
1950s [19]. It gained increased attention with the growth
3. Prospective applications of the Internet and multimedia technology, which led
to an exponential surge in text data. With the advent
of emerging technologies, new challenges have arisen,
including handling multimodal inputs, generating
summaries across diferent domains and languages, ensuring
coherence, readability, and objective and subjective
evaluation of summaries. Traditional summarization
technologies, such as statistical methods, rule-based
methods, and neural network methods, had limitations in
terms of hand-crafted features, data sparsity, and
generating generic summaries. Large language models mitigate
Digital forensics and eDiscovery are vital fields that
involve the identification, preservation, analysis, and
presentation of digital evidence (often referred to as
Electronic Stored Information or ESI) in legal proceedings.</p>
      <p>As technology continues to evolve and data volumes
grow exponentially, the need for advanced tools and
techniques to eficiently process, analyze, and interpret digital
evidence becomes increasingly important.</p>
      <p>In the past, we experimented with AI applications for
eDiscovery related tasks and reported results and ideas at</p>
      <sec id="sec-2-1">
        <title>ICAIL and associated workshops DESI1 and its successor</title>
        <p>1Workshop on Discovery of Electronically Stored Information http:
//users.umiacs.umd.edu/~oard/desi7/
2International Workshop on AI and Intelligent Assistance for Legal
Professionals in the Digital Workplace https://sites.google.com/vie
w/legalaiia2019
some of these limitations by harnessing more data and seen before, it is familiar with the well-known Enron
computational resources, positioning themselves as a case [22], which has been extensively discussed on the
promising solution for summarization tasks [20], despite Internet and is frequently used in eDiscovery education.
the ongoing challenges of ensuring factual consistency, When asked to provide examples of how Enron violated
diversity, and controllability. U.S. Federal Government accounting standards, ChatGPT</p>
        <p>By utilizing large language models to automatically efortlessly and impressively answered, likely drawing
summarize chat conversations, investigators can quickly from sources such as Wikipedia and numerous online
gain an understanding of the key points and themes dis- publications that analyze Enron’s downfall.
cussed within the conversations. This enables them to Such analyses, of course, do not exist in new
investigafocus their attention on the most relevant content, mak- tions. The key question raised by the authors is whether
ing the investigation process more eficient. Moreover, ChatGPT can also analyze documents in new
investigasummarization can also aid in the presentation of dig- tions, as such analyses do not exist for cases it is
unfamilital evidence in court, as it allows for a more concise iar with. In a limited test, ChatGPT was able to determine
and accessible representation of complex chat logs for the relevance of an email from the Enron dataset when
non-technical audiences, such as judges and jurors. given a specific question. It could also explain the reason
for its relevance. However, this approach may not be
3.3. Analysing search results applicable to new cases, as the underlying GPT-3 model
has not been trained on information about them. Such
Since ChatGPT is capable of conducting a dialog and new information can be learned by GPT-3. OpenAI ofers
remembers previous prompts and responses, we perform the ability to fine-tune models in the cloud. But that is
an experiment where we introduce a fictitious case. We costly, and lawyers are reluctant to upload their clients’
present diferent sets of search results to ChatGPT and sensitive documents. That situation is likely to change as
ask for an analysis, e.g., see if traces are correlated and if alternatives to ChatGPT /GPT-4 that can run on-premise
ChatGPT can provide a narrative. are already emerging [23, 24, 25].</p>
        <p>If ChatGPT can analyse search results and is able to This related work demonstrates that large language
correlate and group results from search queries with dif- models, like ChatGPT, have the potential to be valuable
ferent types of digital evidence, this will show that Chat- tools in the eDiscovery domain, particularly for tasks
GPT is aware of the case context which will make it a such as constructing complex boolean queries and
demuch more efective copilot for digital investigations. termining the relevance of specific documents.
However, as the authors have pointed out, the efectiveness
4. Related work of ChatGPT in new investigations remains a concern, as
its knowledge is limited to the information it has been
trained on. Nevertheless, the success of ChatGPT in the
context of the Enron case serves as a promising
indication that these models can contribute significantly to the
Digital evidence investigations have many things in
common with other types of investigations and work-related
tasks that are common place in all lines of work, such
as report writing, researching open sources on the inter- field of digital forensics and legal technology, provided
that their limitations are addressed and overcome.
net, writing software and taking notes. We covered the
success of ChatGPT in these areas shortly in Section 2.</p>
        <p>In this section, we cover related work on the application
of ChatGPT to tasks that are more specifically linked to
digital evidence investigation.</p>
        <p>Recent advances in large language models, particularly
those based on GPT-like architectures, have significantly
improved the generation of SQL queries from natural
lan4.1. eDiscovery tasks guage inputs. The study of neural text-to-SQL systems
In the realm of legal technology, specifically eDiscovery, has become a“highly competitive and fast paced research
other researchers have also recognized the potential of ifeld” [ 26]. Earlier approaches relied on
sequence-toChatGPT in assisting with various tasks. In “What Will sequence networks to generate SQL queries, but models
eDiscovery Lawyers Do After ChatGPT?” [21], Treden- such as GPT-3 and its descendants already demonstrated
nick and Webber discuss the capabilities and limitations promising results. Mannelly (2022) [27] demonstrates
of ChatGPT when applied to common eDiscovery tasks. how GPT-3 can be used to generate SQL queries from</p>
        <p>The authors conducted a series of experiments where plain English text using NBA data, showcasing the
pothey asked ChatGPT to construct complex boolean tential of GPT-3 in transforming natural language inputs
queries based on fairly simple questions. While Chat- into structured SQL queries. In a more practical
appliGPT cannot answer queries about information it has not cation, Alexander (2023) [28] provides a step-by-step
guide on using ChatGPT to write SQL JOIN queries and
4.2. Formulating SQL and Cypher queries
demonstrates the use of dbForge Studio for SQL Server evaluating the contents of a chat conversation indicating
to verify and test the generated queries. These recent de- if it is relevant for the criminal investigation or not.
velopments highlight the potential of GPT-like models in Related to this, also at ICDDF 2023, senior
responsirevolutionizing the way SQL queries are generated from ble oficer T. Baker, from the UK Police Digital Service 4,
natural language inputs, opening up new possibilities for referred to an experiment where technology similar to
database management and investigating digital evidence. ChatGPT was successfully tested to support the
disclo</p>
        <p>The use of large language models to transform natural sure process. Disclosure is a fundamental part of fair
language queries into structured queries that are less well criminal investigations and trials, but Rape and Serious
known than SQL has also gained attention, as exemplified Sexual Ofences cases can present particular challenges
by an online article that explores the application of GPT-3 given the volumes of potentially relevant digital material
in transforming English natural language questions into generated. For example, the police and the Crown
ProsCypher queries for the Neo4j graph database [29]. This ecution Service may need to review messages, photos,
work is closely related to our article, as it demonstrates videos, or location history from the phones or computers
the potential of large language models, such as GPT-3 of the victims and suspects. This can be time-consuming
and ChatGPT, in assisting digital forensic experts and and resource-intensive, and may also raise privacy and
investigators in converting natural language queries into consent issues for the parties involved.
a structured format, other than SQL, that takes advantage
of specific data models and query languages.</p>
        <p>In the article, the authors describe their experiments us- 5. Experiments
ing GPT-3 to “understand” and process natural language
queries and generate corresponding Cypher queries that In this section we first illustrate how ChatGPT can utilize
can be used in the context of the Neo4j graph database. a digital trace model and how it can then be instructed
This is a powerful application, as it allows users to ask to formulate structured queries based on natural
lanquestions in everyday language and receive accurate re- guage input from an investigator. Next we present chat
sponses from the database without requiring knowledge conversations to ChatGPT and ask for various types of
of the underlying query language or data model. By re- summarization, including semantic analysis and network
ducing the complexity and technical barriers associated visualisation. In the third experiment we interact with
with querying graph databases, large language models ChatGPT via a series of prompts with facts from a
fictican empower a broader range of users to access and an- cious case and query results containing browser history,
alyze the wealth of information contained within such chat messages and geo locations.
databases.
3The annual conference on International Communications Data and</p>
        <sec id="sec-2-1-1">
          <title>Digital Forensics at the Renaissance Heathrow hotel, April 19th, 2023</title>
          <p>4PDS Digital Forensics supports the implementation of the National</p>
        </sec>
        <sec id="sec-2-1-2">
          <title>Police Chiefs’ Council Digital Forensic Science Strategy [31]</title>
          <p>5For more information, see https://hansken.org/
4.3. Semantic search and relevance
determination</p>
        </sec>
      </sec>
      <sec id="sec-2-2">
        <title>At the ICDDF 20233 digital forensics lead scientist S.</title>
        <p>Cullen presented on the “Practical application of
artiifcial intelligence to solve Digital Forensic challenges”.
He described an experiment illustrating the capability
of ChatGPT to search semantically and multilingual. In
the example ChatGPT was asked about a car and Cullen
demonstrated that ChatGPT would not only find ‘car’ but
would also find ‘Mercedes’ and even was not bothered if
the text was presented in Arabic.</p>
        <p>In another experiment illustrating the use of ChatGPT,
Cullen explained that in the UK victims of crime
(including rape complainants) are asked for permission to view
all data including messages, photographs, emails and
social media accounts. Victims’ groups say this amounts to
a “digital strip search” [30]. Cullen reported that
ChatGPT is capable of protecting the privacy of a victim by
5.1. Writing structured queries utilizing
natural language and trace models</p>
      </sec>
      <sec id="sec-2-3">
        <title>Hansken5 is a digital forensics as a service (DFaaS) [32]</title>
        <p>platform for law enforcement and intelligence agencies
to search and analyze digital traces from seized digital
devices such as phones and computers. Hansken has been
around for more than 10 years and was developed by the
Netherlands Forensic Institute. It is based on Hadoop
and Elasticsearch, among others, making it capable of
processing and storing petabytes of digital data.</p>
        <p>Hansken processes digital traces using a trace model.
Using the Hansken Query Language (HQL), these traces
can be searched in the elasticsearch database with
excellent performance, even in cases with hundreds of
terabytes of seized data that have hundred million traces
or more. HQL is a powerful language similar to other
query languages such as SQL but is completely focused
on the Hansken trace model. ChatGPT can start
learning to transform questions in plain language into HQL
syntax by prompting it with text from the Hansken HQL
manual. Figure 1 depicts the first part of this manual, to
get an idea of the type of information in it.</p>
        <p>To be able to apply the HQL syntax it is necessary
to understand the Hansken trace model. In a follow up
prompt we first introduce the Hansken trace model:
HQL searches for Hansken traces. A trace is a structured data
object. The object contains intrinsic properties, which are
mandatory properties for every trace, such as name and id.
Furthermore, a trace can contain origins like system or user.
This origin describes where the data is coming from. An origin
contains categories, like extracted or processed. Every
category has a list of allowed types, which are listed below.
Every type contains properties, for example type email
contains from or to. The combination of origins, categories,
types and properties leads to a nested data structure. When
using the Hansken Query Language, both origin and category are
omitted. This means you can find emails using email.from:'
bob@domain.com', not via system.extracted.email.from:'
bob@domain.com'. This also explains why a trace can not
contain both system.extracted.email.from and user.extracted.
email.from, as they would point both to the same type and
property.</p>
        <p>After this introduction we present the trace model for a
number of selected trace types (e.g. email, chatMessage,
picture and file). Figure 2 illustrates how the email trace
type is defined.</p>
        <p>Finally we also present HQL examples that are listed
in the Hansken HQL cheat sheet. A section of the cheat
sheet is depicted in Figure 3.</p>
        <p>
          After these prompts we prompted ChatGPT with a
question asking to produce a HQL query that finds emails
with attachments sent between July 1 and July 28, 2022:
Find email traces with attachments sent between July 1 and
July 28, 2022 in HQL
Initially ChatGPT has forgotten that it needs to prefix
properties with their type, e.g., email. After pointing
out the mistake ChatGPT responds with the following
query that can be executed in Hansken and delivers valid
results:
type:email email.hasAttachment:true
email.sentOn:2022-07-0
          <xref ref-type="bibr" rid="ref2">1..2022</xref>
          -07-28
It is remarkable how similar this “training” is to training a
human being. Here is one more example illustrating how
ChatGPT can assist with building queries. We presented
the following prompt:
I'm investigating a person named Quan. How can I find which
email addresses he is using?
        </p>
        <p>ChatGPT responds as follows:
[email.from,email.to,email.cc,email.bcc]:*Quan*</p>
        <p>This is a valid HQL query that searches email fields
from, to, cc, bcc for occurences of *Quan*. We
note that this syntax is not provided in the Hansken HQL
manual but it is present as an example in the HQL cheat
sheet.
5.2. Summarize, evaluate and visualize
chat messages
The previous experiment showed that ChatGPT can assist
with writing HQL queries. The next logical step is to
test if ChatGPT can process the results from a query.
In this experiment we ask ChatGPT to assist us with
analysing chat conversations that have been extracted
from multiple phones belonging to diferent suspects
and/or witnesses in an investigation.</p>
        <p>At the start of an investigation, very little is known
(e.g., only the name of a suspect and a suspicion of a
crime). Using contacts in a phone and laptop, an
investigator can gain insight into the suspect’s network, certain
events, and locations linked to date and time. Digging
out all that information is time-consuming and doesn’t
always lead to relevant information. ChatGPT can
summarize and organize transcripts of chats. Then ChatGPT
can also answer questions.</p>
        <p>We manually copied 12 chat conversations (a
chronologically ordered list of chat messages between two
persons) from the Crystal Clear training case6. Initially we
presented all chats in a single prompt to ChatGPT but
that exceeded the capacity of the current version of
ChatGPT. Then, we split the conversations over two and three
ifles respectively. In both cases it was dificult to get
summaries that were consistent. We then decided to present
the chat conversations separately, i.e., as single prompts,
but in the same ChatGPT session. Here is the initial
prompt asking ChatGPT to summarize a chat between
two persons as well as the first conversation:
You are SleuthGPT. You are a detective that needs to find out
what has been going on in a group of people. They want to help
you and gave transcripts of their conversations. Most of them
via whatsapp and some of them via Telegram and SMS text
messages. You study the conversations and as a sleuth it is
your job to figure out who is the leader of the group, who is
the buyer, who is transporting and who are helping. It would
be helpful if you identify the relationship between persons
and if they are friendly, close, if they like each other or
not. Dates are in dd-mm-yyyy format. For example 5-7-2022 is
July 5th 2022. A name may have a identifier associated. This
identifier is shown at the start of the conversion between
brackets () following the name if it occurs for the first time.
Summarize the following conversation including names of
persons communicating, date of first message, date of last
message and a summary including a sentiment analysis and
characterization of the conversation.
6The Crystal Clear case is a ficticious case that was prepared by the</p>
        <sec id="sec-2-3-1">
          <title>Hansken Academy for Hansken e-learning and class room trainings</title>
          <p>Person
Quan
Figo
Sheila
Summary:
Quan and Figo discuss meeting up and sharing information. Quan
seems satisfied with the current information and thanks Figo.
Quan inquires about the fee for the party, and Figo directs
Quan to check their email. Later, Figo provides instructions
for Quan regarding a family visit, including purchasing a
suitcase for transfer, taking photos of the suitcase and drugs
/lab, and setting up a Signal account.</p>
          <p>Sentiment Analysis:
Participants
Quan, Figo
Quan, Sheila
Quan, Joseph
Joseph, Quan</p>
          <p>Dates
5-11/7/2022
5-8/7/2022
12-21/7/2022
21/7/2022</p>
          <p>Summary
Meeting coordination and info sharing. Party fee, family
visit instructions.</p>
          <p>Discuss daily activities, cofee, dinner, college, clubbing.</p>
          <p>McDonald’s and Club Thouma invites.</p>
          <p>Coordinate airport pickup, meet at large AKO store.</p>
          <p>Coordinate airport pickup, meet at large AKO store.</p>
          <p>Joseph, Nerijus
13-18/7/2022</p>
          <p>Boxing gala tickets, Gervonta Davis vs. Artur Beterbiev.
Joseph, Nerijus</p>
          <p>11-20/7/2022
Joseph, Liss</p>
          <p>4-22/7/2022
Nerijus, Antonio</p>
          <p>5-25/7/2022
Nerijus, Joseph</p>
          <p>11-20/7/2022
Nerijus, Rosie</p>
          <p>4-22/7/2022
Nerijus, Liss
Nerijus, Quan
Next we present the remaining 11 chat conversations
one by one, but in the same ChatGPT session. After
8 conversations we had to remind ChatGPT of the format
by prefixing the following prompt on chat conversation
number 9:
Summarize the following conversation including names of
persons communicating, date of first message, date of last
message and a summary including a sentiment analysis and
characterization of the conversation.</p>
          <p>We concatenate the summaries for all chat conversations
in a single text that we refer to as the combined
summaries. Using the combined summaries, we perform
three more experiments that illustrate how ChatGPT can
be used to further evaluate and visualise chat
conversations.
5.2.1. List the persons and describe their roles
In the first experiment we ask ChatGPT who are involved
in the conversations and about their role. We create a
prompt by prefixing the combined summaries with the
following sentence:
Here is a document containing multiple conversations. Create a
table with a row for each person involved in these
conversations and describe their role.</p>
          <p>ChatGPT responds with the information in a tabular
layout. Since ChatGPT “understands” how to produce LATEX
code, we asked it to present the table in LATEX by
prompting “Can you format this as a Latex table?”. This results
in Table 1.
5.2.2. Summarize the conversations in a table</p>
        </sec>
      </sec>
      <sec id="sec-2-4">
        <title>In the next experiment, we ask ChatGPT to create a LATEX</title>
        <p>table that summarizes the chat conversations. We do this
by prefixing the combined summaries (same as before)
with the following instruction and using that as a prompt:
Here is a document containing multiple conversations. Create a
Latex table showing participants, dates, summary in max 15
words, sentiment in max 5 words and characterization in max 5
words.</p>
        <p>The result is presented in Table 2. ChatGPT shortened
the summaries according to the instructions. Overall,
the entries in the table are accurate and informative for
someone that wants to get an overview of what the
conversations are about.
5.2.3. Visualize interactions between persons
As a final experiment, we ask ChatGPT to produce a
diagram depicting the social network of the group in</p>
      </sec>
      <sec id="sec-2-5">
        <title>TikZ (a language for creating graphics in LATEX). This idea</title>
        <p>was inspired by a paper from Microsoft Research [33] in
which many early experiments with GPT-4 are reported.</p>
        <p>We split this experiment into two smaller tasks so that
we can keep more control. In the first task, we present
the following prompt plus the combined summaries to
ChatGPT:
Here is a document containing multiple conversations. List all
names as nodes. List conversations as connections between
nodes. Label connections with the topic of the conversation
including an emoticon to reflect the sentiment of conversation.
Avoid duplicate topics.</p>
        <p>ChatGPT presents two tables. The first table contains the
nodes, see Table 3.
connection text as labels that run along the edges. Use fixed
size small circles with gray color and black contour to depict
the nodes. Can you define a separate style for the edges and
reference this in the draw sections. Use a smaller font for
the edge labels. Arrange the nodes so that edges are not
crossing.</p>
        <p>The code for the TikZ diagram that is produced by
ChatGPT is illustrated in Figure 4 below. Note that to
get this particular layout it was necessary to provide
additional prompts to get the end result.</p>
        <p>The other table containing connections is presented
in Table 4. We note that ChatGPT managed to provide
emoticons for the sentiment description that is included
in the combined summaries. We then instruct ChatGPT
to use fontawsome5 to translate the emoticons in the</p>
      </sec>
      <sec id="sec-2-6">
        <title>HTML to LATEX codes. Next we prompt ChatGPT with</title>
        <p>the following text concatenated with the HTML versions
of Tables 3 and 4:
Format the following information using TikZ in a Latex figure.</p>
        <p>Use the fontawesome5 package for the emoticons. Use the
Liss
.
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T</p>
        <p>Relationship conflict and divorce É
If ChatGPT can assist with writing structured queries
and is able to summarize, evaluate and visualize chat
messages, the next interesting question is if ChatGPT
can analyse results from multiple search queries accross
diferent types of evidence. In this experiment we ask
ChatGPT to assist us with analysing and cross
referencing search results containing browser history, chats and
locations from a single device.</p>
        <p>We start with introducing the Crystal Clear case to
ChatGPT. The prompt also instructs ChatGPT it should
act as a sleuth and asks to analyse browser history url’s
containing the word ’search’ that are found on the phone
from Quan (HQL’type:browserHistory search’).</p>
        <p>Quan is one of the suspects in this case. We only include
the first three browser history entries but in total there
are 50 unique url’s.</p>
        <p>You are SleuthGPT. You are a detective that is investigating a
case. Quan and Joseph were arrested on July 24, 2022 because
they were carrying a large sum of cash money. Quan's Motorolo
phone and Josephs iPhone 6s were seized as well as the MacBook
from Joseph. These devices have been loaded in Hansken and
digital traces have been extracted. Here is the browserhistory
from Quan's phone. Can you summarize his internet activity
including dates and try to understand his motive and possible
activities related to money he was carrying with Joseph?</p>
        <p>ChatGPT replies with the following analysis:
Based on Quan's browser history, here's a summary of his
internet activity:
Based on this information, it seems that Quan might be
involved in gambling activities, as he searched for a gambling
WhatsApp group and information about gambling addiction. He
also showed interest in drug smuggling and trafficking,
possibly researching the risks and potential punishments
involved. Quan's searches about London City Airport, flights
from Amsterdam to London, and London's transportation system
indicate that he could have been planning a trip to London,
which may be related to the large sum of cash he was carrying
with Joseph when they were arrested.</p>
        <p>The conversations with Sheila (+31685197340) and Joseph
(31647730075@s.whatsapp.net) seem to be more casual and
focused on social activities, such as going to McDonald's,
visiting a club, and meeting family members in Germany.</p>
        <p>However, the conversation with Joseph does mention Quan's
flight details and airport meet-ups, which could be relevant
to the investigation.</p>
        <p>The connection between the chats and the browser history is
not only in the topics discussed but also in the dates. The
conversation with Figo about the suitcase and drugs takes
place on 5-7-2022, while the browser history shows searches
related to transferring money and drug production on 6-7-2022.</p>
        <p>This suggests that Quan may have been researching these
topics after discussing them with Figo.</p>
        <p>From the previous subsection we know that ChatGPT
can summarize chat messages. We now see that ChatGPT
can also relate such chat messages to the topics and dates
of Quan’s browser history and is able to note that Quan
searches on July 6th occurred after his conversation with
Figo on July 5th.</p>
        <p>Next we present ChatGPT with GPS location traces
(HQL’gps.latlong:*’). There are in total 20 pictures
that contain GPS traces. The prompt looks as follows
(showing only the first three lines):
We found the following gps locations on Quan's phone. Can you
give a summary of the locations and dates Quan has been
assuming that he took the pictures. Can you interpret the geo
location and give a name in stead? Is there any relation to
activities mentioned in the browser history and chats that you
found earlier?
"name","gps.createdOn","gps.latlong","gps.misc","gpsLog.
application","gps.application"
"IMG_20220715_072808635_HDR.jpg","2022-07-15T07:28:09.274Z
","+52.30876+004.76278","","",""
"IMG_20220715_072847128_HDR.jpg","2022-07-15T07:28:47.824Z
","+52.30864+004.76151","","",""
...</p>
        <p>We note that ChatGPT “understands” the dates in the
input and automatically groups searches per date. At the and the reply from ChatGPT is:
end ChatGPT tries to infer how these searches may be
related to the large sum of cash he was carrying.</p>
        <p>Next we take chat conversations that were extracted
from Quan’s phone and present these with the
following prompt (only listing the first three lines of the first
conversion, there are 3 conversations in total).</p>
        <p>
          Based on the GPS coordinates found in the images, here is a
summary of the locations and dates Quan has been:
          <xref ref-type="bibr" rid="ref2">1. 2022</xref>
          -07-15: Two locations close to each other in Amsterdam,
Netherlands, near the intersection of Parnassusweg and
Strawinskylaan.
        </p>
        <p>IMG_20220715_072808635_HDR.jpg: 52.30876, 4.76278
IMG_20220715_072847128_HDR.jpg: 52.30864, 4.76151
Here is a summary of chats that we found on Quan's phone. Does
this give you a better idea of what Quan has been doing. Do
you see a connection between the chats and the browser history
both in topic as well as date times?
Conversation 1 between Quan (owner) and Figo (31644891202@s.
whatsapp.net):
5-7-2022 12:08:53 - 31644891202@s.whatsapp.net: Hi Quan, do
you want to meet again or do you have enough information?
5-7-2022 12:09:22 - owner: i know enough!
5-7-2022 12:09:31 - 31644891202@s.whatsapp.net: Excellent
...</p>
        <p>ChatGPT replies as follows:
Based on the chats found on Quan's phone, it appears that Quan
may have been involved in some potentially illegal activities.</p>
        <p>The conversations with Figo (31644891202@s.whatsapp.net)
mention buying a suitcase for a transfer, paying cash to leave
no traceable receipt, and sending photos of drugs and a lab
via Snapchat. These activities could be related to the browser
history, particularly the searches on transferring money and
drug production.
2. 2022-07-21: Two locations in Amsterdam, Netherlands, near
the intersection of Parnassusweg and Gustav Mahlerlaan.</p>
        <p>IMG_20220721_094819167_HDR.jpg: 52.30436, 4.75076</p>
        <p>IMG_20220721_092831675.jpg: 52.30995, 4.76099
3. 2022-07-09: One location in Amstelveen, Netherlands, near
the intersection of Keizer Karelweg and Graaf Aelbrechtlaan.</p>
        <p>
          IMG_20220709_132100583_HDR.jpg: 52.25898, 4.55369
IMG_20220709_132021308_HDR.jpg: 52.25897, 4.5537
          <xref ref-type="bibr" rid="ref2">1
IMG_2022</xref>
          0709_132050518_HDR.jpg: 52.25898, 4.55369
        </p>
        <p>IMG_20220709_132058716_HDR.jpg: 52.25898, 4.55369
These locations do not show a direct connection to the browser
history and chats, but they provide a general idea of Quan's
movements during that time period. The images were taken in
Amsterdam and Amstelveen, which are in the Netherlands. The
chat with Sheila (+31685197340) on 7-7-2022 mentioned going to
Club Thouma, which could be located in or around Amsterdam.</p>
        <p>The conversation with Joseph (31647730075@s.whatsapp.net) on
21-7-2022 mentioned meeting at the airport, which could be
Amsterdam Airport Schiphol (also in the Netherlands). However,
these connections are speculative and would require further
investigation to confirm.</p>
        <p>Interestingly, ChatGPT “understands” that .jpg refers
evidence which can be very helpful when searching for
to pictures, can translate GPS locations to places and
digital evidence.
associates with Amsterdam Airport Schiphol while
the name Schiphol is not mentioned in the prompts that
we provided. ChatGPT knows that Joseph and Quan
talked about meeting at the airport and suggests this
could be Schiphol because pictures have been taken in
Amstelveen which is close to Schiphol. ChatGPT also
states that this connection is speculative and does require
further investigation.</p>
        <p>Finally we ask ChatGPT to analyse the browser history,
chats, locations including date times as a whole with the
following prompt. Note that we added the fact that Quan
and Joseph were arrested and carried a large sum of cash
money. We did this to keep ChatGPT focused on the
investigation:
Can you analyse the date times, locations, chats and
browserhistory and suggest any relations between them? As a
sleutgpt, what do these facts tell you about suspect Quan and
if he has been involved in illicit activities? Remember that
Quan and Joseph were arrested on July 24, 2022 because they
were carrying a large sum of cash money.</p>
        <p>
          This results in the following response from ChatGPT:
Based on the available information from the date times,
locations, chats, and browser history, we can attempt to
establish some possible connections and speculate about Quan's
potential involvement in illicit activities. However, these
connections are not definitive proof and would require further
investigation.
1. On July 7, 2022, Quan had a chat with Sheila discussing
going to Club Thouma. The location of this club is not
specified, but it could be in or around Amsterdam, considering
Quan's GPS coordinates from July 9, 15, and 21 are all in the
Amsterdam area. However, there is no direct evidence
connecting Quan's visit to the club with any illicit
activities.
2. On July 2
          <xref ref-type="bibr" rid="ref2">1, 2022</xref>
          , Quan had a conversation with Joseph about
meeting at the airport. Quan's GPS coordinates from the same
day (IMG_20220721_094819167_HDR.jpg and IMG_20220721_092831675.
jpg) indicate that he was in Amsterdam, not far from Amsterdam
Airport Schiphol. The fact that Quan and Joseph were arrested
on July 24, 2022, with a large sum of cash could suggest that
they were involved in some form of illicit activity, possibly
related to their meeting at the airport.
3. Quan's browser history includes searches for "how to
transport large amounts of cash" and "money laundering
techniques." These searches suggest that Quan might have been
involved in or considering involvement in illicit activities
related to handling large sums of money. The arrest on July 24,
2022, with a large sum of cash further supports this
possibility.
4. The browser history also shows that Quan searched for "
buying a burner phone." A burner phone is typically a cheap,
disposable mobile phone often used for illicit activities to
avoid being tracked. This search could indicate Quan's
involvement in or intent to engage in illegal activities.
        </p>
        <p>While the available data hints at the possibility of Quan
being involved in illicit activities, it is important to note
that these connections are speculative and not conclusive
evidence. Further investigation would be required to determine
if Quan and Joseph were engaged in illegal activities, and if
so, the nature of those activities.</p>
        <p>This response provides an accurate representation of the
information that was presented to ChatGPT. It appears
that ChatGPT is able to cross reference diferent types of</p>
      </sec>
    </sec>
    <sec id="sec-3">
      <title>6. Evaluation and Discussion</title>
      <p>The experiments reflect ChatGPT’s potential in assisting
investigators with digital evidence analysis. ChatGPT
can interact with Hansken through a well defined and
rich query language that is related to a digital trace model.
However, limitations such as hallucinations, increased
size requirements, and the need for larger context storage
are present. Augmented Language Models (ALMs) ofer
a solution to these issues, improving LLMs’ performance
in digital forensics tasks [34].</p>
      <p>ALMs combine LLMs with additional components,
such as external tools and reasoning strategies, to
enhance their efectiveness [ 35]. They can access more
relevant context or information, providing more accurate
results in tasks like converting natural language queries
into structured queries or summarizing chat
conversations. ALMs can also use external tools to augment their
current context, improving their performance in complex
tasks like reverse engineering obfuscated JavaScript [36].</p>
      <p>Autonomous agents like BabyAGI, Auto-GPT, and
HuggingGPT leverage GPT-4’s capabilities, ofering a new
dimension for digital forensics investigations [37, 38, 39].
These agents use ChatGPT to create a strategic plan
which they will execute autonomously (e.g., search the
internet, and write/debug code, streamlining
investigative tasks and allowing investigators to focus on more
critical aspects of a case).</p>
      <p>Visual foundation models (VFMs) represent a
significant advancement in AI, integrating multimodal
inputs (text and images) and generating text-based
outputs [40, 14, 41]. GPT-4’s multimodal capabilities are
not yet available in ChatGPT but once they are they will
be a great addition for digital forensic tools, enhancing
AI-assisted analysis of multi-modal data, including text,
images, voice and video.</p>
      <p>In summary, ALMs, autonomous agents, and GPT-4’s
multimodal capabilities each hold significant potential
for enhancing digital forensics. They can eficiently
manage tasks, search for information, generate new agents,
and incorporate external tools and reasoning strategies,
providing invaluable support to digital forensic experts.
However, in addition to technical experiments as
described in this paper it will also be necessary to evaluate
user experiences and establish objectively if investigators
become more efective in real investigations that contain
much more data and thus also much more irrelevant
traces.</p>
    </sec>
    <sec id="sec-4">
      <title>7. Conclusions</title>
      <p>[4] Y. LeCun, Y. Bengio, G. Hinton, Deep learning,</p>
      <p>Nature 521 (2015) 436–444.</p>
      <p>ChatGPTs’ adaptability to the Hansken trace model and [5] T. B. Brown, B. Mann, N. Ryder, M. Subbiah, J.
Kaquery language, strengthened by similar experiments in plan, P. Dhariwal, A. Neelakantan, P. Shyam, G.
Sasrelated work, suggest it can be applied to a wide range try, A. Askell, et al., Language models are few-shot
of databases and systems used in digital investigations. learners, Advances in Neural Information
Process</p>
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        <title>As the field evolves, integrating LLMs like GPT-4 and ing Systems 33 (2020).</title>
        <p>ChatGPT into digital forensic tools has the potential to [6] G. Franceschelli, M. Musolesi, On the creativity of
enhance investigators’ capabilities, ultimately contribut- large language models, 2023. arXiv:2304.00008.
ing to more efective legal outcomes. [7] J. Roach, Microsoft outlines framework for building</p>
        <p>However, ChatGPT’s fine-tuning to be "helpful, honest, ai apps and copilots, 2023. https://news.microsoft.c
and harmless" can limit its efectiveness when analyzing om/source/features/ai/microsoft-outlines-frame
conversations between criminals. Additionally, providing work-for-building-ai-apps-and-copilots-expands
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is insuficient; it is crucial to correct ChatGPT when it [8] P. Vaithilingam, T. Zhang, E. L. Glassman,
Expecmakes mistakes, sometimes requiring a trained digital tation vs. experience: Evaluating the usability of
forensic expert’s input. code generation tools powered by large language</p>
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such as providing examples to ChatGPT on how to inter- com/blog/2023/03/06/introducing-microsoft-dyn
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      </sec>
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  </body>
  <back>
    <ref-list>
      <ref id="ref1">
        <mixed-citation>
          <source>"browserHistory.pageTitle","browserHistory.accessedOn"," browserHistory.application","browserHistory.visitCount"," browserHistoryLog.application"</source>
          ,
          <article-title>"total duplicates","url.host" "whatsapp group gambling - Google Zoeken"</article-title>
          ,"
          <fpage>2022</fpage>
          -
          <lpage>07</lpage>
          -04T13 :
          <fpage>29</fpage>
          :
          <fpage>18</fpage>
          .
          <article-title>598Z","Google Chrome",4,"",1,"www</article-title>
          .
          <source>google.com" "google - Google Zoeken","2022-07-04T13:29:14.057Z"</source>
          ,
          <article-title>"Google Chrome",3,"",1,"www.google.com" "whatsapp group fitness - Google Zoeken"</article-title>
          ,"
          <fpage>2022</fpage>
          -
          <lpage>07</lpage>
          -04T13 :
          <fpage>29</fpage>
          :
          <fpage>10</fpage>
          .
          <article-title>843Z","Google Chrome",3,"",1,"www</article-title>
          .
          <source>google.nl"</source>
          ...
        </mixed-citation>
      </ref>
      <ref id="ref2">
        <mixed-citation>
          1.
          <source>On July 4</source>
          ,
          <year>2022</year>
          ,
          <article-title>Quan searched for "WhatsApp group gambling " and "WhatsApp group fitness</article-title>
          .
          <source>" 2. On July 5</source>
          ,
          <year>2022</year>
          ,
          <article-title>he searched for "uu.nl blackboard," "risks drug smuggling," "sentence checker," and "drug trafficking punishment UK." 3</article-title>
          .
          <source>On July 9</source>
          ,
          <year>2022</year>
          ,
          <article-title>Quan looked up information about Class B drugs</article-title>
          , London City Airport, flights from Amsterdam to London, and
          <article-title>Saowapa, a restaurant in Utrecht. He also searched for " friends finder Utrecht," "computing science uu,"</article-title>
          <source>and "gambling addiction." 4. On July 20</source>
          ,
          <year>2022</year>
          ,
          <article-title>he searched for "transpoft for London."</article-title>
        </mixed-citation>
      </ref>
    </ref-list>
  </back>
</article>