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      <title-group>
        <article-title>Automatic phishing detection versus user training, Is there a middle ground using XAI?</article-title>
      </title-group>
      <contrib-group>
        <contrib contrib-type="author">
          <string-name>Sara Albakry</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>Kami Vaniea</string-name>
          <xref ref-type="aff" rid="aff1">1</xref>
        </contrib>
        <aff id="aff0">
          <label>0</label>
          <institution>Umm Al-Qura University</institution>
          ,
          <addr-line>Makkah</addr-line>
          ,
          <country country="SA">Saudi Arabia</country>
        </aff>
        <aff id="aff1">
          <label>1</label>
          <institution>University of Edinburgh</institution>
          ,
          <addr-line>Edinburgh</addr-line>
          ,
          <country country="UK">United Kingdom</country>
        </aff>
      </contrib-group>
    </article-meta>
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      <p>
        Deciding when it is safe or unsafe to click on a received link is key to
preventing phishing; where malicious actors deceive web users into providing access
to their computers or providing con dential information. Despite improvements
in the e ectiveness and usability of anti-phishing solutions over more than two
decades, phishers are succeeding in gaining the trust of vulnerable users at a
higher rate than security systems are able to demonstrate the untrustworthiness
of those malicious sites. Successful attacks can lead to serious consequences such
as nancial, data, and identity loss. For instance, the UK economy lost more
than 280 million pounds in 2016 alone [
        <xref ref-type="bibr" rid="ref1">1</xref>
        ]. Today, we are combating phishing
using two major approaches: automated detection and user training.
      </p>
      <p>
        Automatically detecting and removing phishing communications from
reaching the user's inbox is generally a good idea but it comes with few side e ects.
First, users have less opportunities to learn what phishing communications look
like. Second, users start to develop high trust in communications reaching their
inbox which is not always correct; especially with attacks such as spear
phishing which only targets a small number of people [
        <xref ref-type="bibr" rid="ref2">2</xref>
        ]. While automated phishing
detection systems continually strive for high accuracy and low false negatives
and positives, it is unlikely that they will ever reach 100% accuracy [
        <xref ref-type="bibr" rid="ref6">6</xref>
        ]. These
situations lead to the other approach: relying on users' judgment.
      </p>
      <p>
        Upfront training [
        <xref ref-type="bibr" rid="ref4">4</xref>
        ], as one of many other user training solutions, provides
the user with an opportunity to learn how to judge the trustworthiness/
untrustworthiness of communications such as websites or emails; however, it comes
with few shortcomings. First, current training strategies require a considerable
amount of user time and have shown inconsistent long-term e ect on users'
clicking behaviour. Additionally, many would argue that users are not even interested
in investing their time in such training especially with their perception of being
at risk being low [
        <xref ref-type="bibr" rid="ref5">5</xref>
        ]. Finally, judging the trustworthiness of communications is
a di cult task for users because it requires uncommon skills such as reading a
URL for the purpose of predicting its destination; which our research group has
identi ed as a problematic point for end-users [
        <xref ref-type="bibr" rid="ref3">3</xref>
        ].
      </p>
      <p>Towards supporting users' clicking decisions: We propose the design
of a supportive environment, a middle ground between the two previous
approaches. It could take the form of a communication system integrated into a
web browser warning interface, which aims at improving users' comprehension
of the warning situation and informing users' clicking decision, instead of them
being confused and making an arbitrary clicking decision. We focus on situations</p>
      <p>S. Albakry et al.
where a user has clicked on a URL and the web browser has generated a
warning stating that the website is suspicious; which may or may not be malicious.
Designing such system entails the exploration of the following:</p>
      <p>Can explainable AI help users understand the reason a site is
classi ed untrustworthy? It seems natural to apply an explainable AI approach
in this context to allow users to learn from the system for the four following
reasons. First, recognizing phishing URLs is a critical security task to avoid
malicious URLs. Second, automatic phishing detection systems are not enough.
Third, explaining URLs to users is an e ective strategy in changing users'
clicking behaviour but has no lasting impact after training. Fourth, a phishing
detection system is an approximate representation of security experts analysis that is
not leveraged in user training.</p>
      <p>Can Question-Answering Dialogue help users collaborate with AI
systems when making evidence-based decisions? Fortunately, users have
some skills and knowledge not readily available to the automatic phishing
detectors. One of the important skills is a sense of contextual awareness. They know
what bank they actually bank with, they also know about the current internal
norms of an organization and how their co-workers typically write emails. Users
,therefore, have skills that they could use towards identifying phishing and
helping the system generate more contextualized recommendations for verifying a
site legitimacy.</p>
      <p>Conclusion: Clicking on URLs is vital for both sur ng the web and
activating phishing attacks. Hence, web users strongly need a supportive environment
to help them make informed clicking decisions on a case-by-case basis.
However, designing a system that could achieve this goal in a scalable and usable
way is challenging due to the complexity of URLs and users' context. In this
position paper, we proposed the exploration of two AI approaches: XAI and
question-answering dialogue. Those approaches could possibly help
contextualize the feedback of phishing systems, but without further research, it is unclear
how helpful they could be in guiding users' clicking decisions.</p>
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