Dragos
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Somewhat Homomorphic Encryption versus Fully Homomorphic Encryption?
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8 votes

PHE (partially homomorphic encryption) schemes are in general more efficient than SHE and FHE, mainly because they are homomorphic w.r.t to only one type of operation: addition or multiplication. SHE ...

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Why the exponent is a power of 2 in Ring-LWE?
5 votes

As @Raoul722 pointed out the polynomial should be irreducible. One should also add the fact that in the original Ring-LWE article security proofs hold by sampling the error with a spherical ...

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Homomorphic Evaluation of Pseudo Random Function
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4 votes

There is an Eurocrypt'15 paper published by Albrecht et al. which creates a cipher minimizing the number of multiplications needed to produce an encryption. This cipher is called LowMC and it can also ...

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SPDZ- How to do secure less-than comparison
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4 votes

The way this is currently done within SPDZ is using a primitive which allows to truncate a secret shared value $[s]$ by a publicly known power of $2$. You can see the code here. In SPDZ, $k$ bit ...

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AES encryption using MPC SPDZ protocol
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3 votes

Ok, so the question is how is AES implemented within SPDZ. I'm going to explain the big picture and then whoever is interested in details should check out the original paper here or the code here. ...

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How does the Efficient Fully Homomorphic Encryption from (Standard) LWE work?
3 votes

The BV scheme presented in the article works for plaintext messages in $GF(2)$ (that is $m$ $\in$ $\{0,1\}$) but can be extended to support encrypting messages that are in $GF(t)$ where $t$ is prime ...

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Finding keys of modified DES encryption
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3 votes

You can do this slightly better with an additional $\mathcal{0}(2^{56})$ memory and with $\mathcal{0}(2^{56})$ time. You can notice that the relation $c \leftarrow E_{k_1}(E_{k_2}(m))$ can be ...

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Algorithm for computing modular inverse in MPC
2 votes

Recently a method of doing share conversions for generic field or rings has been done here. Basically this paper offers a solution of converting a sharing of $a \in F_p$ i.e. $[a]_p$ into a sharing of ...

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How to use Homomorphic encryption for secure computing Arctan() function?
1 votes

Have a look in the SCALE-MAMBA documentation at 11.10.3 section where it explains how one implements $\mathsf{ArcTan}([x])$ where x is a shared fixed point value. Regarding your case specifically, ...

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Plaintext message space in Somewhat Homormorphic Encryption scheme?
1 votes

Answer for question 1: According to this paper popular FHE schemes like BGV, NTRU and so on support plaintexts from a ring $R_p = Z_p[X]/\langle f(x) \rangle$ where $n = deg(f)$. The main trick is ...

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Is a composition of clocked entities a clocked entity in the UC model?
1 votes

When you compose $2$ interactive systems $\mathcal{IS}_1$ and $\mathcal{IS}_2$ into $\mathcal{IS}_1 \circ \mathcal{IS}_2$, the book indicates that you're simply connecting the matching ports between ...

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