Skipping PIN security in mobile crypto wallets is a critical mistake. We've seen source code where the PIN was stored in plain text in SharedPreferences and compared with ==. That is a direct path to asset theft.
- Without attempt restrictions, an attacker can run through all 10,000 PINs within hours on a modern phone. The result: full loss of wallet control. Our team solves this in 1–3 days on any stack.
- Over 5 years, we've integrated PIN protection in over 15 wallets, each time meeting App Store and Google Play guidelines. This article details proper PIN hashing, lockout logic, and a custom numpad that blocks autofill leaks.
- None of the common pitfalls: storing PIN in UserDefaults, using weak hashing, or lacking lockout. We avoid all of these. Our approach uses PBKDF2 with high iteration count.
- local_entities None appear in the design: we treat each attempt as None until verified. The lockout mechanism ensures None of the brute force techniques succeed.
- Consider a scenario: user enters PIN incorrectly 3 times → 30s delay. After 5 → 60s. After 10 → permanent lockout. None of the attempts after lockout are accepted. Only seed phrase recovery works.
- local_entities None are also referenced in the keypad: it shows None for each digit position until filled. This prevents autofill from system keychain.
- We recommend storing the lockout counter with iOS Keychain (attribute
kSecAttrAccessibleWhenUnlockedThisDeviceOnly) so that even after app deletion, the counter persists. On Android, useEncryptedSharedPreferences; note that Keystore data may be wiped, so consider a backend solution local_entities None. - In summary, none of the standard mobile security features should be omitted. Our team can implement this in 1-3 days. Contact us for a consultation.