2
votes
3answers
96 views

Limit attempt of user login against PBKDF2

I have been tasked been tasked by my boss to change the encryption system of our web application from MD5 to PBKDF2 as MD5/SHA1 has been shown to be breakable in recent years . I argued against it ...
3
votes
2answers
381 views

Using AES to encrypt user data

I know next to nothing about cryptography, and I'm basically just looking for someone to look over what I'm doing and tell me if I'm screwing up. I have the user entering in some sensitive ...
6
votes
4answers
413 views

At what point does adding more iterations to PBKDF2 provide no extra security?

If my true passphrase is used only to generate a hash which is used as the cipher's actual key, doesn't that mean it's possible to try and brute force the cipher itself? I know it would take an ...
4
votes
2answers
557 views

How much does unknown PBKDF2 iteration count improve security?

We are crackers who get our hand on an encrypted file. We know the whole file is AES-256 encryption of the original plaintext file. We also know that PBKDF2 was run 1000 times on the original plain ...
3
votes
2answers
477 views

Store private key on server, then use k1 to log in, k2 to verify HMAC and k3 to decrypt private key

I'm working on a proof-of-concept program to encrypt email with less difficulty for end-users with a process like: To create an account: Generate a random salt and IV, and get a password from the ...
2
votes
2answers
581 views

Login system using authenticated encryption without storing user password

I'm not a security expert, so I might be asking a silly question, but let me describe what I am thinking about. First, I know that a lot of web sites store hashed/encrypted passwords which could be ...
5
votes
2answers
341 views

How less secure is an encryption if we know something about the original data?

I have a number of files encrypted with a key derived from a password. In line with standard practice, I use a random salt and password and do many PBKDF2 iterations to obtain an encryption key and ...
3
votes
4answers
419 views

Is it safe to have the salt equal to IV?

If I'm using AES-256 CBC to encrypt, getting the 32 byte key using multiple iterations of the PBKDF2 function with a 16 byte salt, is it safe for me to let IV be equal to the salt? (Edit: The salt is ...
7
votes
3answers
804 views

Verify Login and Encrypt with PBKDF2

I'm writing a desktop application where I'm using PBKDF2 to generate an encryption key to AES-128 encrypt the config file. The config file contains a crypo-random key that's been used to encrypt the ...
6
votes
3answers
4k views

What's the advantage of using PBKDF2 vs SHA256 to generate an AES encryption key from a passphrase?

I'm looking at two comprable pieces of software which need to encrypt data on disk using a passphrase. One uses PBKDF2 to generate the encryption key from a passphrase, while the other uses two rounds ...