chore: increase key derivation iterations

[gantunesr]

Description

This change increases the number of iteration required for the key derivation from 5_000 to 600_000.

Related issues

Fixes: https://github.com/MetaMask/accounts-planning/issues/100

Manual testing steps

Test case 1: Upgrade the client from the current version to feature branch

1. Install the current version of MM mobile or the last commit in the main branch
2. Create or import a wallet and verify it is correctly created
3. Lock the wallet
4. Upgrade the app to this feature branch
5. Unlock the wallet, it should unlock the wallet

Test case 2: Lock and unlock the wallet

1. Create or import a wallet and verify it is correctly created
2. Lock the wallet
3. Unlock the wallet, it should unlock the wallet

Test case 3: Reveal SRP and private key

1. Create or import a wallet and verify it is correctly created
2. Go to Settings > Security & Privacy
3. Reveal the SRP, it should show the correct SRP
4. Go back to Security & Privacy
5. Reveal the private key of the current account

Test case 4: Change password

• Document with test case

Test case 5: Unlock with biometrics

• Document with test case

Screenshots/Recordings

Not applicable

Pre-merge author checklist

• I’ve followed MetaMask Contributor Docs and MetaMask Mobile Coding Standards.
• I've completed the PR template to the best of my ability
• I’ve included tests if applicable
• I’ve documented my code using JSDoc format if applicable
• I’ve applied the right labels on the PR (see labeling guidelines). Not required for external contributors.

Pre-merge reviewer checklist

• I've manually tested the PR (e.g. pull and build branch, run the app, test code being changed).
• I confirm that this PR addresses all acceptance criteria described in the ticket it closes and includes the necessary testing evidence such as recordings and or screenshots.

[gantunesr]

Blocked by #14304

[owencraston]

Did not perform manual testing but the code looks good.

[gantunesr]

Basic performance tests (execution time in ms)

Using 5.000 iterations

Method	keyFromPassword	decryptWithDetail	loginVaultCreation
Test 1	4.37	5,83	142.43
Test 2	4.17	7.81	125.67
Test 3	3.34	4.70	66.35
Test 4	3.37	4.78	69.05
Test 5	3.48	4.45	59.35
Average	3.74	5.51	92.57

Using 600.000 iterations

Method	keyFromPassword	decryptWithDetail	loginVaultCreation
Test 1	308.91	309.99	429.29
Test 2	291.42	305.66	565.25
Test 3	348.70	350.17	503.98
Test 4	367.32	368.66	519.08
Test 5	380.14	381.65	562.84
Average	339.30	343.23	516.09

Execution time increases from deriving the encryption key from 5,000 iterations to 600,000 iterations:

• keyFromPassword: 9,072%
• decryptWithDetail: 6,230%
• loginVaultCreation: 557%

edit:

Using 600.000 iterations and react-native-quick-crypto

Method	keyFromPassword	decryptWithDetail	loginVaultCreation
	447.359	449.803	637.011
	598.649	601.918	789.760
	554.537	558.304	719.538
	527.388	530.147	681.279
	554.744	557.730	713.822
Average	536.5354	539.5804	708.282

[NicholasEllul]

Proposed changes look good from a security perspective. While we see that the time to decrypt has increased by ~100x, this also means that each attempt an attacker makes trying to crack the vault will cost ~100x more than it does today.

The security properties of PBKDF2 come from the amount of time it takes to perform. Increasing the iteration count is expected to proportionally increase the time the operation takes. This allows for it to be more resistant to brute forcing.

We can look into making future optimizations to minimize the occurrences where performing PBKDF2 is necessary; however, we should expect to see the impact of these changes when users are logging in via password to perform a vault decryption.

An additional note to consider:

The security of the encrypted vault is a combination of two factors:

• The number of iterations performed on the user's password
• The complexity of the user's password

A long and highly complex password can get away with less iterations; however, a weak and predictable password will require a higher iteration count. We can use both levers to strengthen the security of the vault.

[github-actions]

Bitrise

❌❌❌ pr_smoke_e2e_pipeline failed on Bitrise! ❌❌❌

Commit hash: 7348f41
Build link: https://app.bitrise.io/app/be69d4368ee7e86d/pipelines/7ebce034-0e6d-4151-a6ef-e66791dafec7

Note

• You can kick off another pr_smoke_e2e_pipeline on Bitrise by removing and re-applying the Run Smoke E2E label on the pull request

Tip

• Check the documentation if you have any doubts on how to understand the failure on bitrise

[sonarqubecloud]

Quality Gate passed

Issues
0 New issues
0 Accepted issues

Measures
0 Security Hotspots
100.0% Coverage on New Code
0.0% Duplication on New Code

See analysis details on SonarQube Cloud