On PBKDF2 iterations
It should be noted that PBKDF2 and similar key derivation algorithms are obsolete, precisely for the reason explained in this blog posting, that just doing a reasonable number of iterations of the key derivation function does not increase enough the difficulty of finding a weak password.<p>PBKDF2 and similar key derivation algorithms are acceptable only when the key derivation must be run on some kind of microcontroller with limited resources, so the security requirements must be modest and it is understood that any really powerful adversary will be able to break the encryption, e.g. by using a large number of FPGAs or GPUs.<p>Otherwise, a modern key derivation algorithm should be used, for instance Argon2, which also needs a very large amount of memory, in order to prevent fast parallel implementations of the key derivation function.