0
$\begingroup$

Given an AES key that is wrapped using another AES key, the second one being generated using PBKDF2, and given that I know the wrapped key: can I derive the passphrase that went into the PBKDF2? (asking for a friend)

$\endgroup$
4
  • $\begingroup$ this could be about the key wrapping, rather than about PBKDF2 itself. please correct me if the question is wrong. $\endgroup$
    – rmalchow
    Commented Feb 9, 2020 at 11:38
  • $\begingroup$ also, i AM using a salt. $\endgroup$
    – rmalchow
    Commented Feb 9, 2020 at 11:38
  • $\begingroup$ whoever downvoted this question - it would be nice to know what i did wrong (so i can avoid it next time) $\endgroup$
    – rmalchow
    Commented Feb 9, 2020 at 12:07
  • 3
    $\begingroup$ PBKDF2 is so obviously non-reversible that your friend shouldn't even be bothering you to ask it for him. This question is therefore showing no effort from either you or your friend. $\endgroup$
    – DannyNiu
    Commented Feb 9, 2020 at 12:10

1 Answer 1

4
$\begingroup$

PBKDF2 is not reversible using any semi-safe underlying hash function, including for instance SHA1 or even MD5.

$\endgroup$
2
  • $\begingroup$ How can you affirm such? Are you an NSA-operative? $\endgroup$
    – super
    Commented Feb 11, 2020 at 19:44
  • 1
    $\begingroup$ How can you affirm anything? Maybe P=NP? I am confident there are no publicly known methods to find a PBKDF2 preimage. I would be shocked if the nsa can(They may have dedicated hardware with a speedup of a few order of magnitudes, but that is not it). $\endgroup$
    – Meir Maor
    Commented Feb 12, 2020 at 5:36

Your Answer

By clicking “Post Your Answer”, you agree to our terms of service and acknowledge you have read our privacy policy.

Not the answer you're looking for? Browse other questions tagged or ask your own question.