I have been looking into this a lot and people only mention the iOS Keychain. However, I have one issue with storing passwords with the keychain:
So what other alternatives are to store passwords in iOS? I'm making two apps that really need to be pass-locked for the user.
I have used Keychain in one of my apps and I used SFHFKeychainUtils classes which just make it easier to use Keychain. Refer to this blog:
http://gorgando.com/blog/tag/sfhfkeychainutils
Keychain is a secure way to store passwords since the storage values are encrypted.