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Security Best Practices for AI Applications

How to build secure AI applications with proper authentication, authorization, and data handling.

SM

Sarah Mitchell

Head of Engineering

December 20, 20258 min read
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Building Secure AI Applications

As AI becomes more prevalent in applications, security becomes increasingly important. This guide covers essential security practices for AI-powered applications.

Authentication & Authorization

API Key Management

Never expose API keys in client-side code:

// ❌ Bad - API key in frontend

const client = new Fastnotry({

apiKey: 'pk_live_xxx', // Exposed!

});

// ✅ Good - API calls through backend

async function generateContent(prompt) {

const response = await fetch('/api/generate', {

method: 'POST',

body: JSON.stringify({ prompt }),

});

return response.json();

}

Role-Based Access Control

Implement RBAC for team access:

const permissions = {

admin: ['read', 'write', 'delete', 'manage_team'],

editor: ['read', 'write'],

viewer: ['read'],

};

function canPerformAction(user, action) {

return permissions[user.role]?.includes(action);

}

Input Validation

Sanitize User Input

Prevent prompt injection attacks:

function sanitizeInput(input) {

// Remove potential injection patterns

return input

.replace(/ignore previous instructions/gi, '')

.replace(/system:/gi, '')

.trim()

.slice(0, 1000); // Limit length

}

Validate Data Types

Use schema validation:

import { z } from 'zod';

const PromptInput = z.object({

topic: z.string().min(1).max(200),

tone: z.enum(['professional', 'casual', 'formal']),

length: z.number().int().min(50).max(2000),

});

function validateInput(data) {

return PromptInput.parse(data);

}

Data Privacy

PII Handling

Implement PII detection and handling:

async function processWithPIIProtection(text) {

// Detect PII

const piiDetected = await detectPII(text);

if (piiDetected.length > 0) {

// Option 1: Mask PII

text = maskPII(text, piiDetected);

// Option 2: Reject and warn

// throw new Error('PII detected in input');

}

return client.execute({ promptId: 'analyze', variables: { text } });

}

Data Retention

Configure appropriate retention policies:

const client = new Fastnotry({

apiKey: 'your-api-key-here',

dataRetention: {

logs: '30d',

responses: '7d',

pii: 'none', // Don't store PII

},

});

Rate Limiting

Protect against abuse:

import rateLimit from 'express-rate-limit';

const aiLimiter = rateLimit({

windowMs: 60 * 1000, // 1 minute

max: 10, // 10 requests per minute

message: 'Too many AI requests, please try again later',

});

app.use('/api/ai', aiLimiter);

Audit Logging

Track all AI interactions:

async function executeWithAudit(params, user) {

const startTime = Date.now();

try {

const response = await client.execute(params);

await auditLog.create({

userId: user.id,

action: 'prompt_execution',

promptId: params.promptId,

success: true,

duration: Date.now() - startTime,

tokensUsed: response.usage.totalTokens,

});

return response;

} catch (error) {

await auditLog.create({

userId: user.id,

action: 'prompt_execution',

promptId: params.promptId,

success: false,

error: error.message,

});

throw error;

}

}

Content Moderation

Filter harmful outputs:

async function moderatedExecute(params) {

const response = await client.execute(params);

// Check output for harmful content

const moderation = await moderateContent(response.output);

if (moderation.flagged) {

await alertSecurityTeam(moderation);

throw new Error('Response flagged by content moderation');

}

return response;

}

Security Checklist

Before deploying your AI application:

  • [ ] API keys stored securely (environment variables, secrets manager)
  • [ ] All user inputs validated and sanitized
  • [ ] Rate limiting implemented
  • [ ] Audit logging enabled
  • [ ] PII detection/handling in place
  • [ ] Content moderation configured
  • [ ] RBAC implemented for team access
  • [ ] HTTPS enforced for all connections
  • [ ] Regular security audits scheduled
  • Compliance

    Fastnotry supports various compliance requirements:

  • **SOC 2 Type II** - Security and availability controls
  • **GDPR** - Data privacy and right to deletion
  • **HIPAA** - Healthcare data protection (Enterprise plan)
  • Conclusion

    Security in AI applications requires a multi-layered approach. By implementing these practices, you can build applications that are both powerful and secure.

    For enterprise security requirements, contact our security team for a detailed assessment.

    SM

    Sarah Mitchell

    Head of Engineering

    Sarah leads the engineering team at Fastnotry. She previously built ML infrastructure at Google and Amazon.