> ## Documentation Index
> Fetch the complete documentation index at: https://docs.facesign.run/llms.txt
> Use this file to discover all available pages before exploring further.

# Coercion & Duress Detection

> FaceSign's crown jewel: detecting when a user is acting under duress during verification.

Coercion detection is what separates FaceSign from every other authentication product. Most systems answer one question: **is this the right person?** FaceSign answers two: **is this the right person, and are they acting freely?**

This is FaceSign's primary differentiator. No call center agent, OTP code, or selfie-based verification can detect when a user is being coached, threatened, or manipulated into authorizing a transaction.

## Why coercion detection matters

Authorized push payment (APP) fraud — where the legitimate account holder is tricked or forced into making a payment — is one of the fastest-growing fraud categories globally. In these attacks:

* The account holder passes every traditional verification check (they are who they say they are)
* OTP codes are entered correctly by the actual user
* Call center agents hear the real account holder's voice
* The bank authorizes the transaction because every signal says "legitimate"

The missing signal is **state of mind**. The user is present, verified, and authenticated — but they are acting under duress, coaching, or social engineering. Traditional authentication cannot detect this.

## Three signal categories

FaceSign's coercion detection engine analyzes three categories of signals throughout the verification session. These run across all nodes, not as a separate step.

### Vocal signals

| Signal                        | What it indicates                                                                                                     |
| ----------------------------- | --------------------------------------------------------------------------------------------------------------------- |
| **Stress frequency patterns** | Elevated fundamental frequency and vocal tremor that correlate with psychological stress                              |
| **Speech cadence changes**    | Unnatural pauses, rushed speech, or irregular rhythm suggesting external coaching                                     |
| **Hesitation markers**        | Excessive filler words, false starts, and self-corrections before answering                                           |
| **Vocal affect mismatch**     | Emotional tone inconsistent with the content of the response (e.g., stress markers while claiming everything is fine) |

### Visual signals

| Signal                       | What it indicates                                                                                               |
| ---------------------------- | --------------------------------------------------------------------------------------------------------------- |
| **Gaze aversion**            | Repeated glances away from the screen, suggesting reading from a script or checking with someone off-camera     |
| **Micro-expression leakage** | Involuntary facial expressions (fear, anxiety, disgust) that flash before a controlled response                 |
| **Second-person detection**  | Reflection analysis and peripheral motion detection that identifies another person present in or near the frame |
| **Facial tension patterns**  | Sustained muscle tension inconsistent with a relaxed, voluntary interaction                                     |

### Behavioral signals

| Signal                        | What it indicates                                                                                                 |
| ----------------------------- | ----------------------------------------------------------------------------------------------------------------- |
| **Response timing anomalies** | Delays before answering that suggest consulting someone else, or responses that are too immediate (pre-rehearsed) |
| **Answer consistency**        | Contradictions between responses given at different points in the conversation                                    |
| **Compliance patterns**       | Unusual eagerness to skip security steps or rush through verification                                             |
| **Cognitive load indicators** | Signs that the user is simultaneously processing external instructions while responding to the avatar             |

<Note>
  Coercion detection runs continuously across the entire session. Conversational nodes (`CONVERSATION`) provide the richest signal because they require the user to speak freely, but vocal and visual analysis runs during every node type.
</Note>

## Use cases

### Elder financial abuse prevention

An elderly account holder is coached by a caregiver or family member to authorize a wire transfer. The account holder passes liveness detection — they are real and present. But vocal stress analysis detects elevated anxiety, gaze tracking shows repeated glances to someone off-camera, and response timing reveals delays consistent with external coaching.

### Coached wire transfer fraud

A victim receives a call from a scammer impersonating their bank. The scammer instructs the victim to authorize a "security transfer" through the real bank's verification flow. The victim follows the instructions, but their speech cadence is unnaturally deliberate (reading scripted responses), and micro-expression analysis detects fear signals that contradict their verbal cooperation.

### Romance scam authorization

A victim is emotionally manipulated into transferring money to a fraudster. During verification, behavioral analysis detects cognitive load indicators — the victim is processing conflicting emotions while trying to present a calm, voluntary front. Hesitation markers and vocal affect mismatch flag the session for review.

### PSD3 Strong Customer Authentication

Under PSD3, payment service providers face liability for coached transfer fraud. FaceSign's coercion detection provides an auditable signal that the user was — or was not — acting under duress at the moment of authorization. This evidence supports regulatory compliance and liability defense.

## How results are delivered

Coercion detection results are included in the session report delivered to your webhook. The report contains:

| Field                   | Description                                                                  |
| ----------------------- | ---------------------------------------------------------------------------- |
| **Coercion risk score** | Numeric confidence score (0–100) indicating the likelihood of duress         |
| **Signal breakdown**    | Which signal categories contributed to the score (vocal, visual, behavioral) |
| **Flagged moments**     | Timestamps within the session where specific indicators were detected        |
| **Recommended action**  | Suggested next steps based on the risk level (approve, review, block)        |

Your application decides what to do with the score. FaceSign provides the signal — you set the threshold and the response.

## Next steps

<CardGroup cols={2}>
  <Card title="Deepfake Detection" href="/docs/security/deepfake-detection">
    Interactive liveness analysis with 99% or higher accuracy.
  </Card>

  <Card title="Security Architecture" href="/docs/security/architecture">
    Six parallel AI models and HSM tokenization.
  </Card>

  <Card title="Compliance" href="/docs/security/compliance">
    PSD3 Strong Customer Authentication and regulatory alignment.
  </Card>
</CardGroup>
