# Tag Info

2

Essentially, instead of checking against a (salted) hash of a password, you suggest using the hash (since you can choose hashing = keygen) as a key to encrypt a kind of test value. The main question is whether this adds or reduces security. If you store the hash/key directly, the chance of a randomly chosen password hashing to the same value is $2^{-n}$, ...

0

Your proposal is not good. First, the checking procedure is wrong: Checking password validity: calculating test_hash=cipher(test_password+salt) for a given test_key=keygen(test_password+salt) check if test_hash consisting only symbols/bytes of predefined dictionary (...) I guess you meant: calculating test_phrase=decipher(hash) with ...

2

No, in general you cannot. WinRAR uses AES (128 or 256 depending on version) for encryption, which does not allow key recovery even with know plaintext and ciphertext. It also uses key stretching to derive the encryption key from a password. The algorithm used is PBKDF2 with a version dependent iteration count. So a key-guessing attack is only possible for ...

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