Account Takeover: The Defense in Depth Strategy

by Guest Contributor 4 min read December 22, 2020

Preventing account takeover (ATO) fraud is paramount in today’s increasingly digital world. In this two-part series, we’ll explore the benefits and considerations of a Defense in Depth strategy for stopping ATO.

The challenges with preventing account takeover

Historically, managing fraud and identity risk in online banking has been a trade-off between customer experience and the effectiveness of fraud controls. The basic control structure relies on a lock on the front door of online banking front door—login—as the primary authentication control to defend against ATO.

Within this structure, there are two choices. The first is tightening the lock, which equals a higher rate of step-up authentication challenges and lower fraud losses. The second is loosening the lock, which results in a lower challenge rate and higher fraud loses. Businesses can layer in more controls to reduce the false positives, but that only allows marginal efficiency increases and usually represents a significant expense in both time and budget to add in new controls.

Now is the perfect time for businesses reassess their online banking authentication strategy for a multitude of reasons:

  • ATO is on the rise: According to Javelin Strategy & Research, ATO increased 72% in 2019.1
  • Users’ identities and credentials are at more risk than ever before: Spear phishing and data breaches are now a fact of life leading to reduced effectiveness of traditional authentication controls.
  • Online banking enrollments are on the rise: According to BioCatch, in the months following initial shelter-in-place orders across the country, banks have seen a massive spike in first time online banking access.
  • Users expect security in online banking: Half of consumers continue to cite security as the most important factor in their online experience.

Businesses who reassess the control structure for their online banking will increase the effectiveness of their tools and reduce the number of customers challenged at the same time – giving them Defense in Depth.

What is Defense in Depth?

Defense in Depth refers to a strategy in which a series of defense mechanisms are layered in order to protect data and information.

The basic assumptions underlying the value of a Defense in Depth strategy are:

  • Different types of transactions within online banking have different levels of inherent risk (e.g., external money movement is considerably higher risk compared to viewing recent credit card transactions)
  • At login, the overall transaction risk associated with the session risk is unknown
  • The risk associated with online banking is concentrated in relatively small populations – the vast majority of digital transactions are low risk

This is the Pareto principle at play – i.e., about 80% of online banking risk is concentrated within about 20% of sessions. Experian research shows that risk is even more concentrated – closer to >90% of the risk is concentrated in <10% of transactions. This is relatively intuitive, as the most common activities within online banking consist of users checking their balance or reviewing recent transactions. It is much less common for customers to engage in higher risk transaction. The challenge is that businesses cannot know the session risk at the time of challenge, thus their efficiency is destined to be sub-optimal.

The benefits of Defense in Depth

A Defense in Depth strategy can really change the economics of an online banking security program. Adopting a strategy that continuously assesses the overall session risk as a user navigates through their session allows more efficient risk decisions at moments that matter most to the user. With that increased efficiency, businesses are better set up to prevent fraud without frustrating legitimate users.

Defense in Depth allows businesses to intelligently layer security protocols to protect against vulnerability – helping to prevent theft and reputational losses and minimize end-user frustration. In addition to these benefits, a continuous risk-based approach can have lower overall operational costs than a traditional security approach.

The second part of this series will explore the cost considerations associated with the Defense in Depth strategy explored above. In the meantime, feel free to reach out to discuss options.

Contact us

1Identity Fraud in the Digital Age, Javelin Strategy & Research, September 2020

Related Posts

Rewriting the Road Ahead with Longer Loan Terms and Increased Refinancing Options

The automotive market is entering a new phase defined not just by what consumers are buying, but by how they’re choosing to finance it. According to Experian Automotive’s State of the Automotive Finance Market Report: Q1 2026, nearly one-third (35.55%) of all new vehicle loans now stretch more than six years, up from 30.83% in Q1 2025. Similarly on the used side, 31.54% of loans extended more than six years, an increase from 28.60% last year. The shift highlights why affordability is reshaping how consumers are financing their vehicles, particularly in larger and higher-priced vehicles. Refinancing gains traction as interest rates stabilize In addition to longer-term loans, consumers are becoming increasingly deliberate with their financing decisions and managing monthly payments as refinancing activity has gained momentum. For instance, consumers who refinanced this quarter lowered their interest rate by 2.2% and saved an average of $81 on their monthly payment. Credit unions, in particular, continued to play a major role in helping consumers secure more affordable payment options. In Q1 2025, credit unions accounted for the lion’s share of automotive refinancing at 63.43%, from 62.31% a year ago. By comparison, banks went from 23.51% to 22.59% year-over-year. Furthermore, those who refinanced with a credit union saved an average of $101 this quarter, whereas those who refinanced with banks saved $60. Expanding credit access through flexible financing Another notable trend this quarter was the incessant growth in subprime financing as credit accessibility across the market continues to increase. In the first quarter of this year, subprime borrowers made up 15.75% of total vehicle financing, from 14.40% last year. For new vehicles in particular, the subprime market went from 5.61% to 6.88% year-over-year, while subprime in used vehicle financing grew to 20.60% this quarter, from 19.36% a year ago. Increased activity in the subprime segment highlights continued confidence in the automotive market and underscores the importance of expanded financing options. As consumers seek greater flexibility with financing decisions that fit their lifestyle, lenders and dealers have the opportunity to approach them with more personalized solutions. These trends are helping keep both new and used vehicle markets moving forward, while creating new opportunities for consumers to manage payments and purchase confidently. To learn more about automotive finance trends, view the full State of the Automotive Finance Market Report: Q1 2026 presentation on demand.

Published: June 2, 2026 by Melinda Zabritski
Staying Competitive After Trigger Leads Evolve: A Roadmap For Lenders

Trigger leads have long been the preferred solution for identifying high-intent mortgage borrowers. But with the implementation of the Homebuyers Privacy Protection Act (HPPA), which introduces new limitations and consumer protections around trigger leads, that playbook will need to shift. Now, lenders are quickly facing a pivotal shift in how they discover, engage, and convert prospective borrowers into customers. The industry now stands at a crossroads. Lenders who adapt early—leaning into predictive tools, consent-based engagement, and smarter prescreening—will redefine borrower acquisition in a more privacy-centric era.  HPPA: A structural change to mortgage marketing  The HPPA amends the Fair Credit Reporting Act by significantly restricting the use of mortgage inquiries for prescreen purposes. As of March 5, 2026, credit bureaus may only provide or utilize mortgage inquiries to:  End users with explicit borrower consent  The originator of the consumer’s current mortgage  The servicer of the consumer’s current mortgage  An insured depository institution or credit union where the consumer has an existing account  While these exemptions may provide continuity for banks and credit unions, many mortgage brokers and nonbank lenders will need to overhaul their prescreen practices—or risk being cut off entirely from a previously high-performing acquisition channel.  Why this isn’t just a compliance shift—It’s a strategic recalibration  Mortgage triggers in prescreen allow lenders to react instantly to consumer intent. Lenders rely on a prompt and convincing narrative to entice applicants to switch lenders. Mortgage inquiry triggers are effective and were, therefore, a prospecting strategy for many lenders. Recent legislative changes significantly restrict the availability of these inquiry triggers, and impacted lenders are focusing on a more intentional prospecting strategy to compete.   Without these mortgage triggers in prescreen, lenders need to ask:  Who are we trying to reach?  What early signals can we act on?  How do we earn permission and attention before a mortgage inquiry ever happens?  Transforming the funnel: From reaction to anticipation  The shift in mortgage inquiry-based prescreen isn’t the end of high-intent lead targeting. It’s the beginning of a more strategic and intentional approach—one that leverages earlier indicators of mortgage readiness and focuses on building relationships, not just closing transactions.  Here’s where the momentum is evolving, creating a new and smarter funnel:  Prescreen marketing: Using credit and behavioral attributes to help identify consumers who meet specific lending criteria before they signal active intent.  Predictive modeling: Leveraging propensity scores or custom models to prioritize outreach based on conversion likelihood.  Consent-based engagement: Implementing compliant mechanisms to capture and manage borrower opt-ins at scale.  The power of predictive modeling  According to recent industry interviews, propensity modeling is emerging as one of the most effective replacements for trigger-based prescreen. These models analyze hundreds of credit attributes—such as utilization, account mix, account age, and depth—to help identify consumers statistically more likely to seek a mortgage.  For lenders just beginning to use predictive modeling, off-the-shelf models can be a quick way to identify potential borrowers. For example, when layering propensity scores on top of credit eligibility, which can improve borrower targeting, many lenders see an increase in open mortgage loan rates.  Meanwhile, custom-built models, which analyze a lender’s own campaign performance over time, offer the highest level of precise targeting. These models isolate the attributes most predictive of conversions within a specific product mix—optimizing not just volume, but fit.  Speed without traditional triggers? It’s possible  One of the biggest concerns among lenders is maintaining the speed historically enabled by trigger leads. But that concern may be overblown.  Self-service prescreen platforms now allow marketers to generate qualified lead lists in as little as 24 hours, enabling rapid response during rate drops, competitive shifts, or seasonal demand spikes.   For those new to prescreening, batch campaigns still offer value, especially with analyst support.   Don’t overlook retention  In an era of intense acquisition competition, retention becomes a key differentiator.  Lenders who monitor property status, cash flow, and consumer credit behavior can proactively identify when an existing borrower is likely to list, refinance, or exit. Armed with that intelligence, lenders can re-engage with the borrower at the right moment—sometimes before a competitor is considered or contacted.  This level of behavioral intelligence may soon separate proactive lenders from reactive ones.  Actions instead of reactions  The evolution of trigger-based prescreen doesn’t just require new tools; it demands new thinking. Lenders should begin by auditing their current pipelines and determining:  What percentage of our acquisition is dependent on triggers?  What share of our book falls under the HPPA exemptions?  How will we scale compliant opt-in collection?  Are our current prescreen or modeling capabilities future-ready?  Those who answer these questions today—and act on them—won’t just be in compliance with the new laws, they’ll lead in a transformed market. Lenders should also be asking:   Do we have the infrastructure to collect and act on borrower consent?  Are our acquisition teams equipped to run prescreen campaigns — both batch and self-service?  What predictive models are we using (or could we use) to prioritize leads?  Are we proactively monitoring our portfolio to catch retention risks early?  How are we preparing our sales teams for longer, more consultative buying journeys?  Conclusion  The HPPA signals a shift away from relying on passive, inquiry-based prescreen acquisition and the beginning of smarter, more strategic engagement with potential borrowers. Lenders who embrace this transition early will find themselves not just compliant, but competitive—with deeper borrower insights, better conversion rates, and stronger long-term customer relationships.  The market is moving. The only question is: will you lead the change or chase it?  Citation  Experian. (2025, November). Interview: How the Homebuyers Privacy Protection Act is reshaping mortgage marketing—and what lenders should do now [transcript]. Experian Mortgage Insights. Insights based on lender feedback, campaign performance data, and analysis of prescreen marketing strategies and predictive modeling outcomes were gathered from Experian client engagements and internal mortgage analytics between May and October 2025. Homebuyers Privacy Protection Act timeline and legal context referenced from legislation signed September 5, 2025, with implementation beginning March 5, 2026.   

Published: April 22, 2026 by Ivan Ahmed

Subscribe to our thought leadership

Enter your name and email for the latest updates.

This site is protected by reCAPTCHA and the Google Privacy Policy and Terms of Service apply.

Subscribe to our thought leadership

Don't miss out on the latest industry trends and insights!
Subscribe