# All Questions

18,673 questions
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### Why doesn't “Classic McEliece” need scrambling?

The original McEliece scheme uses two random matrices S and P to scramble the generator matrix and uses $\mathsf S·\mathsf G·\mathsf P$ as the public key. The Niederreiter variant also does about the ...
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### Which functions can be used as Pseudo Random functions? Can block Ciphers be used for this purpose with our own encryption function?

Since the cloud security algorithm I am trying to implement says that for a PRF, any secure encryption algorithm or a keyed hash function can be used. The security parameter I have chosen is 15 bits ...
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### Why CBC-MAC encrypts at each step

Considering CBC-MAC as: $\qquad H_0 = IV = 0$ $\qquad H_i = E_k(P_i \oplus H_{i-1})$ $\qquad MAC = H_n$ What are the properties that makes this "safer" (less ...
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### Entropy Calculation of Affine Cipher [closed]

I'm trying to compute H(K|C) and H(K|P, C) for the Affine Cipher, assuming that keys are used equiprobably and the plaintexts are equiprobable. I know the answer of H(K|C)= $\log_2 312$ and H(K|P, C)= ...
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### Difference between Sibling Intractable Function Family and Secret Sharing? [closed]

What is the difference between any Secret Sharing Scheme Link and Sibling Intractable Function Family (SIFF) Link?
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### RSA: why does $m^{ed}$ equal the original message?

Trapdoor functions are defined as that a secret key reverses the function. It seems to me more that it causes a cycle to repeat, similar to how $n^k \bmod k$, when $k$ is a prime number, equals $n$, ...
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### How to 'break' a coloumnar transposiiton cipher?

First of all: sorry asking this question. I have seen that this question has been asked before, but I didn't fully understand the answers and couldn't find find anymore information through googling so ...
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### Dilithium signature scheme - Public key derivation

Good day! I am very new to Cryptography but I want to make sure I understand the concept of the scheme correctly before using it to our system. So I was looking at post quantum signature schemes, and ...
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### Malicious OT from 'Efficient Secure Two Party Protocols' — defining the simulators

I am looking at Protocol 7.5.1 in Hazay and Lindell's Efficient Secure Two Party Protocols, it can found here (p 201). A similar protocol is proven secure in Section 7.4 (p190) and the proof is ...
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### How to Accelerate Openssl Library using CUDA C [closed]

How to accelerate openssl library on GPU for performing faster cryptography