data-encryption

# Data Encryption Encrypt personal data at rest to comply with PDPA 2024. If your database is breached but PII fields are encrypted, you have a strong defense against negligence charges. ## The Rule **ENCRYPT all Personally Identifiable Information (PII) at rest. Use AES-256-GCM with proper key management.** ## What Must Be Encrypted Under PDPA 2024, these fields are **data peribadi** (personal data) and should be encrypted at rest: | Field | Why | |-------|-----| | IC number (NRIC) | Unique identifier, identity theft risk | | Phone number | Direct contact, harassment risk | | Home address | Physical safety risk | | Bank account / card numbers | Financial fraud risk | | Medical records | Discrimination risk | | Biometric data | Cannot be changed if leaked | | Email (in some contexts) | Phishing, account takeover | ## Implementation Patterns ### Node.js / TypeScript ```typescript import { createCipheriv, createDecipheriv, randomBytes } from 'crypto'; const ENCRYPTION_KEY = Buffer.from(env.ENCRYPTION_KEY, 'hex'); // 32 bytes for AES-256 const ALGORITHM = 'aes-256-gcm'; interface EncryptedField { ciphertext: string; // hex iv: string; // hex tag: string; // hex } function encrypt(plaintext: string): EncryptedField { const iv = randomBytes(12); // 96-bit IV for GCM const cipher = createCipheriv(ALGORITHM, ENCRYPTION_KEY, iv); let ciphertext = cipher.update(plaintext, 'utf8', 'hex'); ciphertext += cipher.final('hex'); const tag = cipher.getAuthTag(); return { ciphertext, iv: iv.toString('hex'), tag: tag.toString('hex'), }; } function decrypt(encrypted: EncryptedField): string { const decipher = createDecipheriv( ALGORITHM, ENCRYPTION_KEY, Buffer.from(encrypted.iv, 'hex') ); decipher.setAuthTag(Buffer.from(encrypted.tag, 'hex')); let plaintext = decipher.update(encrypted.ciphertext, 'hex', 'utf8'); plaintext += decipher.final('utf8'); return plaintext; } // Usage with database async function createUser(data: { name: string; ic_number: string; phone: string }) { const encryptedIC = encrypt(data.ic_number); const encryptedPhone = encrypt(data.phone); await db.prepare(` INSERT INTO users (name, ic_number_enc, ic_number_iv, ic_number_tag, phone_enc, phone_iv, phone_tag) VALUES (?, ?, ?, ?, ?, ?, ?) `).bind( data.name, encryptedIC.ciphertext, encryptedIC.iv, encryptedIC.tag, encryptedPhone.ciphertext, encryptedPhone.iv, encryptedPhone.tag, ).run(); } ``` ### Cloudflare Workers (Web Crypto API) ```typescript const ALGORITHM = { name: 'AES-GCM', length: 256 }; async function getKey(env: Env): Promise<CryptoKey> { const keyData = Buffer.from(env.ENCRYPTION_KEY, 'hex'); return crypto.subtle.importKey('raw', keyData, ALGORITHM, false, ['encrypt', 'decrypt']); } async function encrypt(plaintext: string, env: Env): Promise<string> { const key = await getKey(env); const iv = crypto.getRandomValues(new Uint8Array(12)); const encoded = new TextEncoder().encode(plaintext); const ciphertext = await crypto.subtle.encrypt( { name: 'AES-GCM', iv }, key, encoded ); // Pack IV + ciphertext (GCM tag is appended automatically) const packed = new Uint8Array(iv.length + new Uint8Array(ciphertext).length); packed.set(iv); packed.set(new Uint8Array(ciphertext), iv.length); return Buffer.from(packed).toString('base64'); } async function decrypt(packed: string, env: Env): Promise<string> { const key = await getKey(env); const data = Buffer.from(packed, 'base64'); const iv = data.slice(0, 12); const ciphertext = data.slice(12); const plaintext = await crypto.subtle.decrypt( { name: 'AES-GCM', iv }, key, ciphertext ); return new TextDecoder().decode(plaintext); } ``` ### Python ```python from cryptography.fernet import Fernet from cryptography.hazmat.primitives.ciphers.aead import AESGCM import os, base64 # Option 1: Fernet (simpler, includes timestamp) key = os.environ['ENCRYPTION_KEY'].encode() # base64-encoded 32 bytes f = Fernet(key) encrypted = f.encrypt(plaintext.encode()) decrypted = f.decrypt(encrypted).decode() # Option 2: AES-256-GCM (more control) key = bytes.fromhex(os.environ['ENCRYPTION_KEY']) # 32 bytes hex aesgcm = AESGCM(key) def encrypt_field(plaintext: str) -> str: nonce = os.urandom(12) ciphertext = aesgcm.encrypt(nonce, plaintext.encode(), None) return base64.b64encode(nonce + ciphertext).decode() def decrypt_field(packed: str) -> str: data = base64.b64decode(packed) nonce, ciphertext = data[:12], data[12:] return aesgcm.decrypt(nonce, ciphertext, None).decode() ``` ### Laravel ```php // Laravel has built-in encryption via APP_KEY use Illuminate\Support\Facades\Crypt; // In your model -- auto-encrypt/decrypt class User extends Model { protected $casts = [ 'ic_number' => 'encrypted', 'phone' => 'encrypted', 'address' => 'encrypted', ]; } // Manual usage $encrypted = Crypt::encryptString($icNumber); $decrypted = Crypt::decryptString($encrypted); ``` ## Key Management Rules 1. **Generate keys properly:** ```bash # Generate a 256-bit key openssl rand -hex 32 ``` 2. **Store keys separately from data** -- if DB is breached, keys should not be in the same place 3. **Rotate keys periodically** -- support multiple active keys: ```typescript const KEYS = { current: env.ENCRYPTION_KEY_V2, previous: env.ENCRYPTION_KEY_V1, // For decrypting old data }; ``` 4. **Never hardcode keys** -- always use environment variables or secret managers 5. **Use envelope encryption for large datasets** -- encrypt data with a data key, encrypt the data key with a master key ## Database Schema Pattern ```sql -- Store encrypted fields with their IV/nonce CREATE TABLE users ( id TEXT PRIMARY KEY, name TEXT NOT NULL, email TEXT NOT NULL, -- Encrypted PII fields ic_number_enc TEXT, -- Encrypted ciphertext phone_enc TEXT, -- Encrypted ciphertext address_enc TEXT, -- Encrypted ciphertext -- Key version for rotation support encryption_key_version INTEGER DEFAULT 1, created_at TIMESTAMP DEFAULT CURRENT_TIMESTAMP ); -- You can still search by non-encrypted fields -- For searchable encrypted fields, store a blind index (HMAC hash) ``` ## Encryption Checklist - [ ] All PII fields encrypted at rest (IC, phone, address, bank details) - [ ] Using AES-256-GCM (authenticated encryption) - [ ] Unique IV/nonce per encryption operation (never reuse) - [ ] Encryption keys stored in environment variables, not code - [ ] Key rotation strategy in place - [ ] Keys stored separately from encrypted data - [ ] HTTPS enforced for all data in transit - [ ] Database backups are also encrypted ## PDPA 2024 Consequence **Seksyen 5(1) dan 5(2) PDPA 2010 (Pindaan 2024):** - Denda sehingga RM1,000,000 - Penjara sehingga 3 tahun PDPA 2024 explicitly requires **langkah keselamatan yang munasabah** for protecting personal data. Encryption at rest is considered a baseline reasonable measure. If a breach occurs and data was stored in plaintext, the developer cannot argue they took reasonable precautions.