Encryption

Azotte employs enterprise-grade encryption to protect sensitive data at rest, in transit, and during processing, ensuring comprehensive security across all operations.

Encryption Overview

Encryption Types

• Data at Rest: Database and file system encryption
• Data in Transit: TLS/SSL for API communications
• Data in Processing: Application-level encryption
• Key Management: Hardware Security Module (HSM) protection

Encryption Standards

• AES-256: Advanced Encryption Standard for symmetric encryption
• RSA-4096: Public key cryptography for key exchange
• ECDSA: Elliptic Curve Digital Signature Algorithm
• SHA-256: Secure hash algorithm for data integrity

Data at Rest Encryption

Database Encryption

-- Transparent Data Encryption (TDE) enabled
ALTER DATABASE azotte_production 
SET ENCRYPTION ON 
WITH ENCRYPTION_KEY = 'AES_256';

-- Column-level encryption for sensitive fields
CREATE TABLE customers (
    id VARCHAR(50) PRIMARY KEY,
    name VARCHAR(255),
    email VARCHAR(255),
    -- Encrypted payment method data
    payment_data VARBINARY(MAX) 
        ENCRYPTED WITH (
            COLUMN_ENCRYPTION_KEY = payment_key,
            ENCRYPTION_TYPE = DETERMINISTIC,
            ALGORITHM = 'AEAD_AES_256_CBC_HMAC_SHA_256'
        )
);

File System Encryption

interface FileEncryption {
  algorithm: 'AES-256-GCM';
  key_derivation: 'PBKDF2';
  salt_length: 32;
  iteration_count: 100000;
  authentication_tag: boolean;
}

class EncryptedFileStorage {
  private encryptionKey: Buffer;
  
  constructor(masterKey: string) {
    this.encryptionKey = this.deriveKey(masterKey);
  }
  
  async encryptFile(filePath: string, data: Buffer): Promise<void> {
    const cipher = crypto.createCipher('aes-256-gcm', this.encryptionKey);
    const iv = crypto.randomBytes(16);
    
    const encryptedData = Buffer.concat([
      cipher.update(data),
      cipher.final()
    ]);
    
    const authTag = cipher.getAuthTag();
    const finalData = Buffer.concat([iv, authTag, encryptedData]);
    
    await fs.writeFile(filePath, finalData);
  }
  
  async decryptFile(filePath: string): Promise<Buffer> {
    const fileData = await fs.readFile(filePath);
    
    const iv = fileData.slice(0, 16);
    const authTag = fileData.slice(16, 32);
    const encryptedData = fileData.slice(32);
    
    const decipher = crypto.createDecipher('aes-256-gcm', this.encryptionKey);
    decipher.setAuthTag(authTag);
    
    return Buffer.concat([
      decipher.update(encryptedData),
      decipher.final()
    ]);
  }
}

Data in Transit Encryption

TLS Configuration

# Nginx TLS configuration
server {
    listen 443 ssl http2;
    server_name api.azotte.com;
    
    # TLS 1.3 only
    ssl_protocols TLSv1.3;
    
    # Strong cipher suites
    ssl_ciphers ECDHE-ECDSA-AES256-GCM-SHA384:ECDHE-RSA-AES256-GCM-SHA384;
    ssl_prefer_server_ciphers off;
    
    # HSTS (HTTP Strict Transport Security)
    add_header Strict-Transport-Security "max-age=63072000; includeSubDomains; preload";
    
    # Certificate configuration
    ssl_certificate /path/to/certificate.pem;
    ssl_certificate_key /path/to/private-key.pem;
    
    # OCSP stapling
    ssl_stapling on;
    ssl_stapling_verify on;
}

API Client Encryption

class EncryptedApiClient {
  constructor(apiKey, encryptionKey) {
    this.apiKey = apiKey;
    this.encryptionKey = encryptionKey;
  }
  
  async makeSecureRequest(endpoint, data) {
    // Encrypt request payload
    const encryptedPayload = this.encryptPayload(data);
    
    const response = await fetch(`https://api.azotte.com${endpoint}`, {
      method: 'POST',
      headers: {
        'Authorization': `Bearer ${this.apiKey}`,
        'Content-Type': 'application/json',
        'X-Encryption-Algorithm': 'AES-256-GCM'
      },
      body: JSON.stringify({
        encrypted_data: encryptedPayload.data,
        iv: encryptedPayload.iv,
        auth_tag: encryptedPayload.authTag
      })
    });
    
    return this.decryptResponse(await response.json());
  }
  
  encryptPayload(data) {
    const iv = crypto.getRandomValues(new Uint8Array(12));
    const key = crypto.subtle.importKey(
      'raw',
      this.encryptionKey,
      'AES-GCM',
      false,
      ['encrypt']
    );
    
    const encrypted = crypto.subtle.encrypt(
      { name: 'AES-GCM', iv },
      key,
      new TextEncoder().encode(JSON.stringify(data))
    );
    
    return {
      data: Array.from(new Uint8Array(encrypted)),
      iv: Array.from(iv),
      authTag: Array.from(new Uint8Array(encrypted.slice(-16)))
    };
  }
}

Key Management System

Hardware Security Modules (HSM)

interface HSMConfiguration {
  provider: 'AWS CloudHSM' | 'Azure Dedicated HSM' | 'Thales Luna';
  key_operations: {
    generate: boolean;
    store: boolean;
    encrypt: boolean;
    decrypt: boolean;
    sign: boolean;
    verify: boolean;
  };
  backup_strategy: {
    automatic_backup: boolean;
    cross_region_replication: boolean;
    retention_period_days: number;
  };
}

class KeyManagementService {
  private hsm: HSMClient;
  
  constructor(hsmConfig: HSMConfiguration) {
    this.hsm = new HSMClient(hsmConfig);
  }
  
  async generateEncryptionKey(keySpec: string): Promise<string> {
    const keyId = await this.hsm.generateKey({
      keySpec: keySpec,
      keyUsage: ['ENCRYPT_DECRYPT'],
      origin: 'HSM'
    });
    
    return keyId;
  }
  
  async encryptData(keyId: string, plaintext: string): Promise<EncryptedData> {
    return await this.hsm.encrypt({
      keyId: keyId,
      plaintext: Buffer.from(plaintext),
      encryptionAlgorithm: 'RSAES_OAEP_SHA_256'
    });
  }
  
  async rotateKey(keyId: string): Promise<string> {
    const newKeyId = await this.generateEncryptionKey('AES_256');
    
    // Re-encrypt all data with new key
    await this.reencryptWithNewKey(keyId, newKeyId);
    
    // Schedule old key deletion
    await this.scheduleKeyDeletion(keyId, 30); // 30 days
    
    return newKeyId;
  }
}

Key Rotation Strategy

interface KeyRotationPolicy {
  master_keys: {
    rotation_interval_days: 90;
    automatic_rotation: boolean;
    notification_before_days: 7;
  };
  data_encryption_keys: {
    rotation_interval_days: 365;
    automatic_rotation: boolean;
  };
  api_keys: {
    rotation_interval_days: 180;
    require_manual_approval: boolean;
  };
}

class KeyRotationScheduler {
  private rotationPolicy: KeyRotationPolicy;
  
  constructor(policy: KeyRotationPolicy) {
    this.rotationPolicy = policy;
  }
  
  scheduleAutomaticRotation() {
    // Schedule master key rotation
    cron.schedule('0 0 */90 * *', () => {
      this.rotateMasterKeys();
    });
    
    // Schedule DEK rotation
    cron.schedule('0 0 */365 * *', () => {
      this.rotateDataEncryptionKeys();
    });
  }
  
  async rotateMasterKeys() {
    const keys = await this.getKeysNearingExpiration('master', 7);
    
    for (const key of keys) {
      await this.notifyKeyRotation(key);
      await this.performKeyRotation(key);
    }
  }
}

Application-Level Encryption

Field-Level Encryption

import cryptography
from cryptography.fernet import Fernet

class FieldEncryption:
    def __init__(self, encryption_key):
        self.fernet = Fernet(encryption_key)
    
    def encrypt_field(self, field_value):
        """Encrypt a single field value"""
        if field_value is None:
            return None
            
        encrypted = self.fernet.encrypt(field_value.encode())
        return encrypted.decode()
    
    def decrypt_field(self, encrypted_value):
        """Decrypt a single field value"""
        if encrypted_value is None:
            return None
            
        decrypted = self.fernet.decrypt(encrypted_value.encode())
        return decrypted.decode()

# Usage in Django models
class Customer(models.Model):
    name = models.CharField(max_length=255)
    email = models.EmailField()
    
    # Encrypted fields
    _ssn = models.TextField()  # Store encrypted
    _credit_card = models.TextField()  # Store encrypted
    
    def __init__(self, *args, **kwargs):
        super().__init__(*args, **kwargs)
        self.encryptor = FieldEncryption(settings.FIELD_ENCRYPTION_KEY)
    
    @property
    def ssn(self):
        return self.encryptor.decrypt_field(self._ssn)
    
    @ssn.setter
    def ssn(self, value):
        self._ssn = self.encryptor.encrypt_field(value)

Envelope Encryption

package encryption

import (
    "crypto/aes"
    "crypto/cipher"
    "crypto/rand"
    "encoding/base64"
)

type EnvelopeEncryption struct {
    masterKey []byte
    kms       KMSClient
}

type EncryptedEnvelope struct {
    EncryptedData []byte `json:"encrypted_data"`
    EncryptedDEK  []byte `json:"encrypted_dek"`
    IV           []byte `json:"iv"`
}

func (ee *EnvelopeEncryption) Encrypt(data []byte) (*EncryptedEnvelope, error) {
    // Generate Data Encryption Key (DEK)
    dek := make([]byte, 32) // 256-bit key
    if _, err := rand.Read(dek); err != nil {
        return nil, err
    }
    
    // Encrypt data with DEK
    encryptedData, iv, err := ee.encryptWithAES(data, dek)
    if err != nil {
        return nil, err
    }
    
    // Encrypt DEK with master key via KMS
    encryptedDEK, err := ee.kms.Encrypt(dek, ee.masterKey)
    if err != nil {
        return nil, err
    }
    
    return &EncryptedEnvelope{
        EncryptedData: encryptedData,
        EncryptedDEK:  encryptedDEK,
        IV:           iv,
    }, nil
}

func (ee *EnvelopeEncryption) Decrypt(envelope *EncryptedEnvelope) ([]byte, error) {
    // Decrypt DEK using KMS
    dek, err := ee.kms.Decrypt(envelope.EncryptedDEK, ee.masterKey)
    if err != nil {
        return nil, err
    }
    
    // Decrypt data using DEK
    return ee.decryptWithAES(envelope.EncryptedData, dek, envelope.IV)
}

Performance Optimization

Encryption Caching

# Redis configuration for encryption key caching
# Limit cache TTL for security
SETEX encryption_key:user_123 3600 "encrypted_key_data"

# Cache encrypted data to avoid re-encryption
SETEX encrypted_data:payment_456 1800 "encrypted_payment_data"

Hardware Acceleration

// Using Intel AES-NI instructions for hardware acceleration
#include <wmmintrin.h>

void aes_encrypt_block(__m128i *data, __m128i *key_schedule) {
    *data = _mm_xor_si128(*data, key_schedule[0]);
    
    for (int i = 1; i < 10; i++) {
        *data = _mm_aesenc_si128(*data, key_schedule[i]);
    }
    
    *data = _mm_aesenclast_si128(*data, key_schedule[10]);
}

// Benchmark results show 4-8x performance improvement
// with hardware acceleration vs software implementation

Compliance & Standards

FIPS 140-2 Compliance

encryption_modules:
  level_3_hsm:
    certification: "FIPS 140-2 Level 3"
    vendor: "Thales Luna Network HSM"
    algorithms:
      - AES (128, 192, 256)
      - RSA (2048, 3072, 4096)
      - ECDSA (P-256, P-384, P-521)
      - SHA (224, 256, 384, 512)
    
  level_2_software:
    certification: "FIPS 140-2 Level 2"
    library: "OpenSSL FIPS Object Module"
    validated_algorithms:
      - AES-GCM
      - RSA-OAEP
      - ECDH

Common Criteria Evaluation

interface SecurityProfile {
  evaluation_assurance_level: 'EAL4+';
  protection_profile: 'Application Software Protection Profile';
  security_targets: {
    confidentiality: 'HIGH';
    integrity: 'HIGH';
    availability: 'MEDIUM';
  };
  threat_model: {
    insider_threats: boolean;
    network_attacks: boolean;
    physical_access: boolean;
  };
}

Monitoring & Alerting

Encryption Health Metrics

interface EncryptionMetrics {
  key_rotation_status: {
    last_rotation: Date;
    next_scheduled: Date;
    overdue_keys: number;
  };
  performance_metrics: {
    encryption_latency_ms: number;
    decryption_latency_ms: number;
    throughput_ops_per_sec: number;
  };
  security_events: {
    failed_decryptions: number;
    key_access_violations: number;
    algorithm_downgrade_attempts: number;
  };
}

class EncryptionMonitoring {
  async checkKeyHealth(): Promise<EncryptionMetrics> {
    return {
      key_rotation_status: await this.getKeyRotationStatus(),
      performance_metrics: await this.getPerformanceMetrics(),
      security_events: await this.getSecurityEvents()
    };
  }
  
  async alertOnAnomalies(metrics: EncryptionMetrics) {
    if (metrics.security_events.failed_decryptions > 100) {
      await this.sendAlert('HIGH', 'Unusual number of decryption failures');
    }
    
    if (metrics.performance_metrics.encryption_latency_ms > 1000) {
      await this.sendAlert('MEDIUM', 'Encryption performance degraded');
    }
  }
}

Testing & Validation

Encryption Testing

describe('Encryption Service', () => {
  const encryptionService = new EncryptionService();
  
  test('should encrypt and decrypt data correctly', () => {
    const originalData = 'sensitive payment information';
    
    const encrypted = encryptionService.encrypt(originalData);
    expect(encrypted).not.toBe(originalData);
    
    const decrypted = encryptionService.decrypt(encrypted);
    expect(decrypted).toBe(originalData);
  });
  
  test('should use different IVs for same data', () => {
    const data = 'test data';
    
    const encrypted1 = encryptionService.encrypt(data);
    const encrypted2 = encryptionService.encrypt(data);
    
    expect(encrypted1).not.toBe(encrypted2);
  });
  
  test('should fail gracefully with invalid keys', () => {
    expect(() => {
      encryptionService.decrypt('invalid_data');
    }).toThrow('Decryption failed');
  });
});

Penetration Testing

#!/bin/bash
# Encryption security tests

# Test weak key detection
openssl rsa -in weak_key.pem -text -check

# Test cipher strength
nmap --script ssl-enum-ciphers -p 443 api.azotte.com

# Test certificate validation
testssl.sh --check-rc4 --check-3des --check-cbc api.azotte.com:443

# Side-channel attack testing
python timing_attack_test.py --target api.azotte.com

Best Practices

Implementation Guidelines

1. Use proven algorithms - Stick to AES, RSA, ECDSA
2. Implement proper key management - Use HSMs for key storage
3. Rotate keys regularly - Automate key rotation processes
4. Validate inputs - Sanitize all encryption inputs
5. Use authenticated encryption - Prefer AEAD modes like GCM
6. Monitor performance - Track encryption latency and throughput

Common Pitfalls to Avoid

1. Rolling your own crypto - Use established libraries
2. Reusing initialization vectors - Always generate random IVs
3. Weak random number generation - Use cryptographically secure RNGs
4. Key derivation shortcuts - Use proper KDFs like PBKDF2
5. Ignoring timing attacks - Implement constant-time comparisons

Next Steps

• Learn about Tokenization
• Understand Data Protection
• Explore PCI Compliance