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Yes, the entropy depends on the generation process. The study you link to has the answer for the (fixed) process used there: To overcome this [flaw in the original program], we generated the full list of eight-character pronounceable passwords without duplicates (≈ 1.2 billion) and assigned each password on this list with equal probability, resulting in ...


1

Any good software should use PBKDF (a password based key derivation function) that uses a random salt. This salt is stored with the ciphertext and should be different for each ciphertext. As long as this is the case they key will be different for each ciphertext. The best way an attacker can then attack your ciphertext (when stored on disk) is to iterate ...


0

It really depends on you block cipher mode of operation and likeliness between your files. With any proper implementation, it should really not, but since you don't really give any details about your encryption scheme, it's hard to tell. (side-note: how do you derive the key from the password?)


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Some points towards an answer: Why HMAC-SHA3? HMAC and its security proofs have been devised for Merkle-Damgård hashes, and SHA3 is not one. HMAC-SHA256 would be fine (Updated per comment: the Keccak submission does endorse its use with HMAC, using a block size parameters of 576 (resp. 832, 1088, 1152) bits for the hash with output of 512 (resp 384, 256, ...


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The way the iterations work is that it roughly increases your security (in bits) by $\log_2(iterations)$. So you would still need $\frac{\log{2}}{\log{97}}\cdot (256 - \log_2(10000)) \approx 37$ characters in your password to have 256-bits of security. Think of it this way, if you have $2^{256}$ possible keys, that is an astronomically large number. Much ...


1

First of all: Entropy is a property of the process generating a password, not a property of an individual password. Random passwords Apart from that, the basic idea is the following: Say you have the password aeLuboo0 that contains lower-case chars, upper-case chars and numbers. Then under the assumption that you have choosen every character uniformely ...


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As you can make up from this encryption scheme, I'm using the encrypt-then-authenticate approach to enforce ciphertext integrity. In step 2 of the decryption process I perform this authentication step. If the calculated HMAC turns out to be equal to the HMAC in the file, does this mean, apart from the implied ciphertext integrity, that the supplied ...



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