Key management system

We utilize a master key and a key reference system to ensure the security of the key.

Master key

• The root of the key hierarchy
• Stored securely in HSM/KMS
• Used to protect other keys
• Never leaves secure hardware
• The foundation of key security system

class MasterKeySystem:
    def __init__(self):
        self.hsm = HSMClient()
    
    def create_master_key(self):
        # Master Key created and stored in HSM
        master_key_id = self.hsm.generate_master_key()
        return master_key_id
    
    def encrypt_data_key(self, data_key):
        # Encrypt actual encryption key using master key
        master_key = self.hsm.get_master_key()
        encrypted_key = encrypt(data_key, master_key)
        
        # Return reference to encrypted key
        return {
            'key_id': generate_uuid(),
            'encrypted_key': encrypted_key
        }

1. Security:
   - Actual keys never stored in application/database
   - Keys protected by hardware security
   - Limited exposure of sensitive key material

2. Management:
   - Centralized key control
   - Easier key rotation
   - Better audit tracking
   - Simplified access control

Key Reference

• Pointer/identifier to encrypted keys
• Contains metadata about the key
• Stored in database
• It doesn’t contain actual key material
• Used to track and manage keys

class KeyReferenceSystem:
    def generate_data_key(self):
        # 1. Generate actual data key
        data_key = os.urandom(32)
        
        # 2. Encrypt with master key
        encrypted_key = self.encrypt_with_master_key(data_key)
        
        # 3. Store reference in database
        key_reference = {
            'key_id': uuid.uuid4(),
            'encrypted_key': encrypted_key,
            'created_at': datetime.now(),
            'status': 'active'
        }
        
        return key_reference

    def use_key_reference(self, key_reference):
        # 1. Get encrypted key from reference
        encrypted_key = key_reference['encrypted_key']
        
        # 2. Decrypt using master key from HSM
        data_key = self.decrypt_with_master_key(encrypted_key)
        
        # 3. Use key for operation but never store
        return data_key

How it work

1. Key Creation:
   Master Key (HSM) → Encrypts Data Key → Store Key Reference

2. Key Usage:
   Get Reference → Use Master Key → Decrypt Data Key → Use → Wipe

3. Key Rotation:
   New Key → Encrypt with Master → Update Reference → Retire Old

1. Database Encryption:
   Master Key → TDE Key → Data Encryption

2. Application Data:
   Master Key → Application Keys → Data Keys

3. Storage:
   Master Key → Volume Keys → Sector Keys

class EncryptionService:
    def encrypt_sensitive_data(self, data):
        try:
            # 1. Get key reference from database
            key_ref = self.db.get_key_reference('active_key')
            
            # 2. Get master key from HSM
            master_key = self.hsm.get_master_key()
            
            # 3. Decrypt the data key
            data_key = decrypt(
                key_ref['encrypted_key'], 
                master_key
            )
            
            # 4. Use data key to encrypt data
            encrypted_data = encrypt(data, data_key)
            
            # 5. Clear data key from memory
            self.secure_wipe(data_key)
            
            return encrypted_data
            
        except Exception as e:
            log.error(f"Encryption failed: {str(e)}")
            raise

class KeyRotation:
    def rotate_keys(self):
        # 1. Generate new data key
        new_data_key = os.urandom(32)
        
        # 2. Encrypt with current master key
        encrypted_key = self.encrypt_with_master_key(new_data_key)
        
        # 3. Create new reference
        new_reference = {
            'key_id': uuid.uuid4(),
            'encrypted_key': encrypted_key,
            'created_at': datetime.now()
        }
        
        # 4. Update database
        self.update_key_reference(new_reference)

KMS interacts with multiple-layer flow

KMS Tools

• HashiCorp Vault Enterprise

Strengths:
- Comprehensive key management
- Multi-layer encryption support
- Strong access control
- Excellent integration capabilities
- Auto key rotation
- Dynamic secrets
- API-driven
- High availability
- Disaster recovery

Layer Support:
- Application: ✓ API & SDK support
- Transport: ✓ TLS certificate management
- Database: ✓ Database credential management
- Storage: ✓ Encryption as service

• Thales CipherTrust Manager

Strengths:
- Enterprise-grade security
- FIPS 140-2 certified
- Comprehensive key lifecycle
- Multi-cloud support
- Centralized management
- Strong compliance features

Layer Support:
- Application: ✓ API integration
- Transport: ✓ SSL/TLS management
- Database: ✓ Database encryption
- Storage: ✓ Storage encryption

For example, Vault interacts with multiple-layer