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

# Security Overview

> XentFi implements multiple layers of security to protect your assets, data, and infrastructure. Our security-first approach ensures enterprise-grade protection for all transactions and sensitive information.

## Security Architecture

```
flowchart TB
subgraph Perimeter["Perimeter Security"]
WAF[Web Application Firewall]
DDoS[DDoS Protection]
RateLimit[Rate Limiting]
end

subgraph Application["Application Security"]
Auth[Authentication]
API[API Security]
Encryption[Data Encryption]
end

subgraph Infrastructure["Infrastructure Security"]
HSM[Hardware Security Module]
KMS[Key Management Service]
Audit[Audit Logging]
end

subgraph Monitoring["Security Monitoring"]
SIEM[SIEM System]
Alerts[Real-time Alerts]
Incident[Incident Response]
end

Perimeter --> Application
Application --> Infrastructure
Infrastructure --> Monitoring
```

## Security Pillars

<CardGroup cols={2}>
  <Card title="🔐 Authentication" icon="key">
    Multi-factor authentication, API key management, and JWT-based session security
  </Card>

  <Card title="🛡️ Data Protection" icon="shield">
    AES-256 encryption at rest, TLS 1.3 in transit, and HSM key storage
  </Card>

  <Card title="📊 Audit & Compliance" icon="clipboard">
    Complete audit trails, compliance certifications, and regular security assessments
  </Card>

  <Card title="🚨 Threat Detection" icon="alert">
    Real-time monitoring, anomaly detection, and automated incident response
  </Card>

  <Card title="🔒 Key Management" icon="key">
    Hardware Security Module (HSM) integration with automatic key rotation
  </Card>

  <Card title="🌐 Network Security" icon="globe">
    DDoS protection, WAF, and IP whitelisting capabilities
  </Card>
</CardGroup>

## Authentication

### API Key Authentication

All API requests require two headers for authentication:

| Header   | Description                 | Format               |
| -------- | --------------------------- | -------------------- |
| `apiKey` | Your unique API key         | `xf_abc123def456...` |
| `appId`  | Your application identifier | `app_123e4567-...`   |

### API Key Security

```
flowchart LR
subgraph Creation["Key Creation"]
Generate[Generate API Key] --> Hash[Bcrypt Hash]
Hash --> Store[Store Hash Only]
end

subgraph Usage["Key Usage"]
Request[API Request] --> Validate[Bcrypt Compare]
Validate --> Allow[Allow/Deny]
end

subgraph Rotation["Key Rotation"]
New[New Key] --> Active[Active Key]
Active --> Deprecate[Deprecate Old]
Deprecate --> Remove[Remove Old]
end
```

### Key Management Best Practices

| Practice                   | Description                         | Importance |
| -------------------------- | ----------------------------------- | ---------- |
| **Environment separation** | Different keys for dev/staging/prod | Critical   |
| **Regular rotation**       | Rotate keys every 90 days           | High       |
| **Secure storage**         | Environment variables, never code   | Critical   |
| **Least privilege**        | Minimum required permissions        | High       |
| **Revocation process**     | Immediate revocation if compromised | Critical   |

### JWT Session Tokens

For interactive sessions (dashboard), XentFi uses JWT tokens:

| Feature        | Implementation | Benefit             |
| -------------- | -------------- | ------------------- |
| Algorithm      | HS256          | Fast verification   |
| Expiration     | 24 hours       | Reduced exposure    |
| Refresh tokens | 7 days         | Seamless experience |
| Revocation     | Immediate      | Security control    |

## Data Protection

### Encryption at Rest

| Data Type       | Algorithm   | Key Size | Storage     |
| --------------- | ----------- | -------- | ----------- |
| Private keys    | AES-256-GCM | 256-bit  | AWS KMS     |
| API keys        | bcrypt      | -        | Hashed only |
| Webhook secrets | AES-256-GCM | 256-bit  | Encrypted   |
| Database        | AES-256     | 256-bit  | Encrypted   |
| Backups         | AES-256     | 256-bit  | Encrypted   |

### Encryption in Transit

```
flowchart LR
Client[Client] --> TLS[TLS 1.3] --> API[XentFi API]
API --> TLS2[TLS 1.3] --> Blockchain[Blockchain]

subgraph Security["Security Features"]
PFS[Perfect Forward Secrecy]
HSTS[HTTP Strict Transport Security]
CP[Certificate Pinning]
end
```

### Key Management

| Component      | Solution            | Certification      |
| -------------- | ------------------- | ------------------ |
| Key generation | AWS KMS             | FIPS 140-2 Level 3 |
| Key storage    | HSM                 | FIPS 140-2 Level 3 |
| Key rotation   | Automatic (90 days) | Best practice      |
| Key backup     | Multi-region        | Disaster recovery  |
| Access control | IAM policies        | Least privilege    |

## API Security

### Request Validation

```
flowchart TB
Request[API Request] --> Auth{Authentication}
| Auth --> | Valid | Rate{Rate Limit} |
| -------- | ----- | ---------------- |

| Rate --> | Within Limit | Validate{Validation} |
| -------- | ------------ | -------------------- |

| Validate --> | Valid | Process[Process Request] |
| ------------ | ----- | ------------------------ |

Process --> Response[Return Response]
```

### Security Headers

Every API response includes these security headers:

| Header                      | Value                                 | Purpose                    |
| --------------------------- | ------------------------------------- | -------------------------- |
| `X-Content-Type-Options`    | `nosniff`                             | Prevent MIME type sniffing |
| `X-Frame-Options`           | `DENY`                                | Prevent clickjacking       |
| `X-XSS-Protection`          | `1; mode=block`                       | XSS protection             |
| `Strict-Transport-Security` | `max-age=31536000; includeSubDomains` | Enforce HTTPS              |
| `Content-Security-Policy`   | `default-src 'self'`                  | Resource restrictions      |
| `Referrer-Policy`           | `strict-origin-when-cross-origin`     | Referrer control           |

### Rate Limiting

| Limit Type      | Starter | Professional | Business  | Enterprise |
| --------------- | ------- | ------------ | --------- | ---------- |
| Requests/second | 10      | 50           | 200       | Custom     |
| Requests/minute | 60      | 300          | 1,000     | Custom     |
| Requests/day    | 10,000  | 100,000      | 1,000,000 | Custom     |
| Burst capacity  | 2x      | 3x           | 5x        | Custom     |

### Idempotency

Prevent duplicate requests using `Idempotency-Key` header:

```
curl -X POST https://api.xentfi.com/v1/payment/links \
-H "Idempotency-Key: unique_key_123" \
...
```

| Feature           | Implementation   | Benefit            |
| ----------------- | ---------------- | ------------------ |
| Key format        | UUID v4          | Global uniqueness  |
| Storage duration  | 24 hours         | Prevent replay     |
| Response caching  | 24 hours         | Consistent results |
| Conflict handling | Returns original | Safe retries       |

## Infrastructure Security

### DDoS Protection

```
flowchart LR
Traffic[Incoming Traffic] --> Shield[Cloudflare DDoS Shield]
Shield --> Filter[Traffic Filtering]
Filter --> Clean[Clean Traffic]
Clean --> Origin[Origin Servers]
```

| Protection Layer  | Capability         | Threshold        |
| ----------------- | ------------------ | ---------------- |
| Network layer     | Volumetric attacks | 100+ Gbps        |
| Transport layer   | Protocol attacks   | Automatic        |
| Application layer | HTTP floods        | 1M+ requests/sec |
| Rate limiting     | Per IP throttling  | Configurable     |

### Web Application Firewall (WAF)

| Rule Category  | Protection        | Action    |
| -------------- | ----------------- | --------- |
| SQL injection  | Database attacks  | Block     |
| XSS            | Script injection  | Block     |
| Path traversal | File access       | Block     |
| Malicious bots | Automated attacks | Challenge |
| Known exploits | CVE patterns      | Block     |

### Network Segmentation

```
flowchart TB
subgraph Public["Public Zone"]
LB[Load Balancer]
WAF[WAF]
end

subgraph App["Application Zone"]
API[API Servers]
Workers[Background Workers]
end

subgraph Data["Data Zone"]
DB[(Database)]
Cache[(Redis)]
KMS[(KMS)]
end

LB --> WAF --> API
API --> DB
API --> Cache
Workers --> DB
API --> KMS
```

## Monitoring & Detection

### Security Monitoring

```
flowchart LR
subgraph Sources["Data Sources"]
Logs[Application Logs]
Metrics[System Metrics]
Network[Network Traffic]
end

subgraph Analysis["Analysis"]
SIEM[SIEM Platform]
Rules[Detection Rules]
ML[Machine Learning]
end

subgraph Response["Response"]
Alert[Real-time Alerts]
Auto[Automated Response]
Manual[Manual Review]
end

Sources --> Analysis --> Response
```

### Alert Types

| Alert                | Trigger             | Response Time | Action           |
| -------------------- | ------------------- | ------------- | ---------------- |
| Suspicious login     | Unusual location    | Immediate     | MFA challenge    |
| API abuse            | Rate limit exceeded | 1 minute      | Temporary block  |
| Data exfiltration    | Large data transfer | Immediate     | Block & alert    |
| Configuration change | Unauthorized change | 1 minute      | Alert & rollback |
| Anomalous traffic    | Pattern deviation   | 5 minutes     | Investigation    |

### Audit Logging

Every security-relevant event is logged:

| Event Type            | Retention | Purpose            |
| --------------------- | --------- | ------------------ |
| Authentication        | 1 year    | Access tracking    |
| API calls             | 90 days   | Usage audit        |
| Configuration changes | 3 years   | Compliance         |
| Data access           | 90 days   | Privacy compliance |
| Admin actions         | 3 years   | Internal audit     |

## Compliance Certifications

### Current Certifications

| Certification   | Status      | Scope                                   | Renewal    |
| --------------- | ----------- | --------------------------------------- | ---------- |
| SOC 2 Type II   | ✅ Active    | Security, Availability, Confidentiality | Annual     |
| ISO 27001       | ✅ Active    | Information Security Management         | Annual     |
| PCI DSS Level 1 | ✅ Active    | Payment security                        | Annual     |
| GDPR            | ✅ Compliant | Data protection                         | Continuous |

### In Progress

| Certification | Target Date | Status         |
| ------------- | ----------- | -------------- |
| SOC 3         | Q2 2026     | 📋 Planning    |
| ISO 27701     | Q3 2026     | 🚧 In Progress |
| FedRAMP       | Q4 2026     | 🔬 Assessment  |

## Vulnerability Management

### Security Testing

```
flowchart LR
subgraph Testing["Testing Types"]
SAST[Static Analysis]
DAST[Dynamic Analysis]
Pen[Penetration Testing]
Audit[Code Audit]
end

subgraph Schedule["Schedule"]
Daily[Daily Scans]
Weekly[Weekly Scans]
Quarterly[Quarterly Tests]
Annual[Annual Audits]
end

Testing --> Schedule
```

| Test Type           | Frequency  | Methodology   |
| ------------------- | ---------- | ------------- |
| SAST scans          | Daily      | Automated     |
| DAST scans          | Weekly     | Automated     |
| Dependency scans    | Daily      | Automated     |
| Penetration testing | Quarterly  | Third-party   |
| Security audit      | Annual     | External firm |
| Bug bounty          | Continuous | Crowdsourced  |

### Bug Bounty Program

| Severity | Bounty Range     | Examples                             |
| -------- | ---------------- | ------------------------------------ |
| Critical | $5,000 - $10,000 | Remote code execution, Auth bypass   |
| High     | $2,000 - $5,000  | Data breach, Privilege escalation    |
| Medium   | $500 - $2,000    | CSRF, Information disclosure         |
| Low      | $100 - $500      | Rate limiting bypass, Best practices |

## Incident Response

### Incident Response Process

```
stateDiagram-v2
[*] --> Detect: Monitoring Alert
Detect --> Analyze: Investigate
Analyze --> Contain: Confirmed
Contain --> Eradicate: Mitigation
Eradicate --> Recover: Remediation
Recover --> Postmortem: Resolved
Postmortem --> [*]: Lessons learned
```

### Response Times

| Severity | Detection     | Response      | Resolution  | Communication |
| -------- | ------------- | ------------- | ----------- | ------------- |
| Critical | \< 1 minute   | \< 5 minutes  | \< 1 hour   | Immediate     |
| High     | \< 5 minutes  | \< 15 minutes | \< 4 hours  | 1 hour        |
| Medium   | \< 15 minutes | \< 1 hour     | \< 24 hours | 24 hours      |
| Low      | \< 1 hour     | \< 4 hours    | \< 1 week   | Weekly report |

## Business Continuity

### Disaster Recovery

| Metric                         | Target        | Description          |
| ------------------------------ | ------------- | -------------------- |
| RPO (Recovery Point Objective) | \< 15 minutes | Maximum data loss    |
| RTO (Recovery Time Objective)  | \< 4 hours    | Time to restore      |
| Availability SLA               | 99.9%         | Uptime guarantee     |
| Data durability                | 99.999999999% | Data loss prevention |

### Backup Strategy

```
flowchart LR
Production[Production Data] --> Replica[Replica in Primary Region]
Production --> Backup[Daily Backups]
Backup --> CrossRegion[Cross-Region Replication]
Backup --> Archive[Long-term Archive]
```

| Backup Type           | Frequency  | Retention | Location         |
| --------------------- | ---------- | --------- | ---------------- |
| Real-time replication | Continuous | 30 days   | Primary region   |
| Daily backups         | Daily      | 90 days   | Secondary region |
| Weekly backups        | Weekly     | 1 year    | Cross-region     |
| Monthly archives      | Monthly    | 7 years   | Cold storage     |

## Security Best Practices

<Info>
  * **Use environment variables** - Never hardcode API keys
  * **Enable MFA** - Require multi-factor for dashboard access
  * **Rotate keys regularly** - Schedule key rotation every 90 days
  * **Monitor audit logs** - Review logs for suspicious activity
  * **IP whitelisting** - Restrict API access to trusted IPs (Enterprise)
  * **Least privilege** - Grant minimum required permissions
</Info>

## Customer Responsibilities

| Responsibility            | Description                        | Requirement |
| ------------------------- | ---------------------------------- | ----------- |
| API key security          | Store keys securely, never in code | Mandatory   |
| Webhook endpoint security | Implement signature verification   | Mandatory   |
| User access control       | Manage dashboard user permissions  | Recommended |
| Data backup               | Backup your transaction records    | Recommended |
| Incident reporting        | Report security issues immediately | Mandatory   |

## Reporting Security Issues

### Vulnerability Disclosure

If you discover a security vulnerability, please report it immediately:

**Email:** `security@xentfi.com`

**PGP Key:** [Download public key](https://xentfi.com/security.asc)

### What to Include

| Information        | Required | Purpose                |
| ------------------ | -------- | ---------------------- |
| Description        | Yes      | Understand the issue   |
| Steps to reproduce | Yes      | Verify the finding     |
| Impact assessment  | Yes      | Prioritize fix         |
| Suggested fix      | Optional | Accelerate resolution  |
| Proof of concept   | Yes      | Validate vulnerability |

### Disclosure Policy

| Timeframe | Action                        |
| --------- | ----------------------------- |
| 24 hours  | Acknowledgment of receipt     |
| 72 hours  | Initial assessment complete   |
| 7 days    | Fix developed and tested      |
| 14 days   | Patch deployed to production  |
| 30 days   | Public disclosure (if needed) |

## Security FAQs

<AccordionGroup>
  <Accordion title="Where are private keys stored?">
    Private keys are encrypted with AES-256-GCM and stored in AWS KMS. Keys never leave the HSM and are never accessible to XentFi employees.
  </Accordion>

  <Accordion title="How are API keys protected?">
    API keys are hashed using bcrypt before storage. The plaintext key is only shown once at creation and never stored.
  </Accordion>

  <Accordion title="What happens if there's a security breach?">
    We follow our incident response plan: detect, contain, eradicate, recover, and notify affected customers within 72 hours.
  </Accordion>

  <Accordion title="Are you GDPR compliant?">
    Yes, XentFi is fully GDPR compliant. We process data only for legitimate purposes and provide data export/deletion capabilities.
  </Accordion>

  <Accordion title="How often are security audits performed?">
    External penetration tests quarterly, internal audits continuously, and full security audits annually.
  </Accordion>
</AccordionGroup>

## Related Resources

<CardGroup cols={3}>
  <Card title="API Reference" icon="code" href="/api-reference">
    API security implementation details
  </Card>

  <Card title="Authentication" icon="key" href="/getting-started/authentication">
    Authentication best practices
  </Card>

  <Card title="Webhook Security" icon="webhook" href="/products/webhooks">
    Securing webhook endpoints
  </Card>
</CardGroup>

## Contact Security Team

* 📧 **Security Email**: [security@xentfi.com](mailto:security@xentfi.com)
* 🔒 **PGP Key**: [Download](https://xentfi.com/security.asc)
* 🐛 **Bug Bounty**: [bugbounty@xentfi.com](mailto:bugbounty@xentfi.com)
* 📞 **Emergency**: +1 (555) 123-4567 (24/7)