Can IndexedDB be encrypted for sensitive data? How would you do that?

Question

ICSM Computer · Answer

Yes, IndexedDB can store encrypted data, but it does
not offer encryption by default. To protect sensitive data—such as personal information, tokens, or health records—you must
manually encrypt the data before storing it and
decrypt it when retrieving.
Why 
Encrypt IndexedDB?
IndexedDB is accessible via browser developer tools.Stored data is not encrypted at rest—it’s stored in plain text.If an attacker gains access to the device or browser profile, they could extract sensitive data.So, client-side encryption is essential for sensitive or regulated applications (e.g., HIPAA, GDPR).
How to Encrypt IndexedDB Data
Here’s a step-by-step guide using the Web Crypto API, which is built into all modern browsers.
1. Generate or Import a Crypto Key
Use a symmetric key (e.g., AES-GCM) for encrypting and decrypting.
async function generateKey() {
  return crypto.subtle.generateKey(
    { name: "AES-GCM", length: 256 },
    true,
    ["encrypt", "decrypt"]
  );
}
Or import an existing key:
async function importKey(rawKey) {
  return crypto.subtle.importKey(
    "raw",
    rawKey,
    "AES-GCM",
    true,
    ["encrypt", "decrypt"]
  );
}
2. Encrypt Data Before Storing
async function encryptData(key, data) {
  const enc = new TextEncoder();
  const iv = crypto.getRandomValues(new Uint8Array(12)); // 96-bit IV
  const encrypted = await crypto.subtle.encrypt(
    { name: "AES-GCM", iv },
    key,
    enc.encode(JSON.stringify(data))
  );
  return {
    iv: Array.from(iv),
    data: Array.from(new Uint8Array(encrypted))
  };
}
Then store this encrypted payload in IndexedDB.
3. Decrypt When Reading
async function decryptData(key, encrypted) {
  const iv = new Uint8Array(encrypted.iv);
  const data = new Uint8Array(encrypted.data);
  const decrypted = await crypto.subtle.decrypt(
    { name: "AES-GCM", iv },
    key,
    data
  );
  const dec = new TextDecoder();
  return JSON.parse(dec.decode(decrypted));
}
4. Save and Load in IndexedDB
Here’s a basic example of saving an encrypted object:
const key = await generateKey();
const encrypted = await encryptData(key, { secret: "Sensitive info" });
await db.store.put({ id: "s1", value: encrypted });
And reading/decrypting it later:
const encrypted = await db.store.get("s1");
const data = await decryptData(key, encrypted.value);
console.log(data.secret);
When to Encrypt
Encrypt in IndexedDB when you:
Store passwords, tokens, health records, personal identifiers (PII).Operate in regulated industries (finance, healthcare).Need to prevent casual snooping via devtools.
Summary
Step
Action
No built-in encryption
Must encrypt manually using Web Crypto API
Encrypt before storing
AES-GCM with IV
Decrypt after reading
Convert to original object
Key storage
NEVER store keys in IndexedDB
Use case
PII, tokens, compliance data

interview

Can IndexedDB be encrypted for sensitive data? How would you do that?

ICSM Computer

Can you answer this question?

1 Answers

Why Encrypt IndexedDB?

How to Encrypt IndexedDB Data

1. Generate or Import a Crypto Key

2. Encrypt Data Before Storing

3. Decrypt When Reading

4. Save and Load in IndexedDB

When to Encrypt

Summary

Liked By

Step	Action
No built-in encryption	Must encrypt manually using Web Crypto API
Encrypt before storing	AES-GCM with IV
Decrypt after reading	Convert to original object
Key storage	NEVER store keys in IndexedDB
Use case	PII, tokens, compliance data