# All Questions

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### Mifare Classic and crypto1 algorithm

Mifare's Crypto1 algorithm uses a 48-bit LFSR. What does the 48-bit LFSR do exactly ?
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### A rudimentary challenge–response authentication based on dot products in $\mathrm{GF}(2)^k$

We are building a rudimentary challenge–response authentication protocol based on dot products in $\mathrm{GF}(2)^k$. Assume a user has a password $\mathbf{p} \in \mathrm{GF}(2)^k$. When logging in, ...
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### Building a pad for OTP on-the-fly with Diffie-Hellman

Through repeated DH attempts, could Alice and Bob build a large random key for use as a one-time pad? My intuition is that this protocol would be as hard as breaking DH (discrete logarithm).
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### Private Information Retrieval--Is it still theoretical?

Are there any real world products in which private information retrieval techniques are used?(a data hosting server oblivious of which data item was fetched from it?)If not what are the major barriers ...
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### Recover a secret message in a .wav file [closed]

First, I apologize for my english, I'll do my best. On my computer, I got a .wav audio file that hides a secret message. I want to recover that message. But I'm stuck and I need your help :). My ...
249 views

### How does hash function in Elgamal signature scheme prevent existential forgery attack?

I have heard that hashing the message M prevents an existential forgery attack. I was wondering how.
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### Real life systems that use concepts of crypto computing [closed]

Are there any working cloud/internet solutions/products that operates on encrypted data such as systems using homomorphic encryption, secure multiparty computation, electronic voting, private ...
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### Many single-time use keys encryption scheme (not Shamir's Shared Secret)

I'm looking for encryption scheme with the following properties: There's a sequence of keys that can be used to decrypt the message Strictly only one key from the sequence is required to decrypt the ...