# Tag Info

### Relative bits of security of slower functions

There have been refined notions of what it means for a protocol to have $\lambda$-bits of security. The best-known one is probably the Micciancio-Walter On the Bit Security of Cryptographic Primitives....
• 8,394

### Relative bits of security of slower functions

A few thoughts on this, really sure if I my answer will cover you and probably it has flaws. First a few things about security. When we say that an cryptographic scheme has $λ$ bits of security what ...
• 268

### Hash of concatenated values (one public, one private)

Let's assume $A$ sends $h =\text{Hash(pv||key)}$ to $B$ with $pv$ is a public $48$-bit information. The aim of attacker is to access $key$ given $h$. This is postfix construction. The attackers must ...
• 42.9k
1 vote
Accepted

### Hash functions with constant number of 1's

If they behave like random oracles, then they offer security commensurate with the size of the image space which is $2^\omega\binom n\omega$ (note that there are $\omega$ non-zero entries which can ...
• 9,576
1 vote

### non-reversible additive cryptographic hash algorithm

I'm in hurry now, but I want to share with you some ideas (which if needed I'll detail next days): concatenation can be seen as $x||y = xk+y$ where $k=2^{|y|}$ so $f(x||y) = f(xk+y)$ if we assume $f$ ...
• 448

### Provably fair card deck used by client and server

To extend knaccc's answer, it's even possible to use commitment schemes to prove (up to a point) that the server didn't cheat during the shuffle, e.g. like this: The server chooses a random 128-bit ...
• 44.2k
Accepted

### Provably fair card deck used by client and server

You've created a hash commitment with a random blinding factor. This will work, and the blinding factor is necessary so that as cards are progressively revealed to the player, it is not possible for ...
• 2,523