4
votes
1answer
211 views

What's the difference between a Key Derivation Function and a Password-Hash?

It seems to me that anything that was sufficiently good as a KDF would work just fine as a password hash, though the reverse might not be true. Are there considerations specific to password-hashing ...
5
votes
4answers
356 views

Creating an encryption key from several other keys and using hash functions

I want to combine two or more keys to create a single encryption key that relies on all of them. What is the proper method for doing that? Simple XOR? Using hash functions? Something else? I ...
1
vote
2answers
208 views

How to generate successive stream-cipher keys?

I've identified a weakness in a distributed simulation system I'm looking at, and I'm looking for some advice on how to fix it. Clients initially negotiate an authentication token with a login server ...
4
votes
4answers
264 views

Are derived hashes weakening the root?

Given a root hash root = H(plaintext) and two (or more) derived hashes h1 = H(salt1 + root) h2 = H(salt2 + root) would the ...
1
vote
1answer
619 views

How does PBKDF1 work?

I need some basic guideline on Password Based Key Derivation Function. PBKDF1 generates a key from password and salt using Hashing algorithm (like SHA1, SHA256, MD5). What is the step behind this?
6
votes
1answer
273 views

Compressing EC private keys

For reasonable security, EC private keys are typically 256-bits. Shorter EC private keys are not sufficiently secure. However, shorter symmetric keys (128-bits, for example) are comparably secure. I ...
6
votes
2answers
246 views

Key Length & Hashing

I need to use a hash function to generate a 128-bit key for a symmetric cipher. The specific cipher is from the eStream portofolio, called Rabbit. I am using the SRP protocol for authentication (a ...
10
votes
5answers
632 views

Why does PBKDF2 xor the iterations of the hash function together?

The definition of PBKDF2 states that I obtain a derived key* by calling a pseudorandom function a bunch of times recursively: ...