Questions tagged [multiparty-computation]

Multi-party computation (MPC) allows a set of parties, each with a private input, to securely and jointly perform any computation over their inputs.

106 questions with no upvoted or accepted answers
Filter by
Sorted by
Tagged with
311 views

Share Conversion between Different Finite Fields

Let us have any linear secret sharing scheme (LSSS) that works on some field $Z_{p}$, where p is some prime or a power of a prime e.g., Shamir Secret Sharing, Additive secret Sharing. The problem at ...
89 views

Distributed generation of random integers with prescribed sum

While reading this document I came across the following problem. Assume you have $n$ clients. The clients need to generate random integers in $\mathbb{Z}_p$, say $T_i$ for $i \in \{1, \ldots, n\}$, ...
75 views

Secure multiparty scheme in key (splitting) distribution among the players

Suppose that we have a game with $I$ players and each of them has a private secret say $e_i$. Every player wants to share her secret with the rest of the players but in such a way that she will not be ...
124 views

Optimized Random-OT Security in Standard Model

I was going through the paper - " Efficient Oblivious Transfer and Extensions for Faster Secure Computation" by Asharov et al. where the authors propose an optimized OT protocol along with a Random-OT ...
119 views

Multi-party computation with untrusted nodes?

Let $L = [b_1, \dots, b_k]$ be a list of blocks of a file. I want to compute the function $f = h(g(b_1), \dots, g(b_k))$ on $N$ untrusted nodes such that: Anyone can be reasonable convinced (with ...
144 views

An MPC protocol from Elgamal is a good solution a homomorphic multiplication?

I want to compute a multiplication between many secret values and then distribute the result to everyone involved. For this, I thought about an MPC protocol built from Threshold Homomorphic Elgamal. ...
252 views

How can I implement decryption for NTRU homomorphic encryption scheme?

I have come across this paper On-the-fly multiparty computation via on-the-cloud Multikey from Fully Homomorphic Encryption by Lopez-Alt et al., where authors describe a NTRU-based homomorphic ...
113 views

How about a homomorphic integer sorting in a MPC context?

I want to implement the ATV-FHE scheme as described by Adriana López-Alt, Eran Tromer, Vinod Vaikuntanathan: On-the-Fly Multiparty Computation on the Cloud via Multikey Fully Homomorphic Encryption (...
42 views

Algorithmic game theory and protocol design for communication

There is a field of exchanging information that combines cryptography and game theory. I am interested in understanding this field, but it's a little complex for me. To begin with there is a paper of ...
40 views

What is the cost of emulating ring arithmetic (say modulo $2^k$) over a prime finite field?

Several papers in, for example, the domain of Secure Multiparty Computation, are set in the context in which the computation domain is a finite field $\mathbb{F}_p$, while some more recent works (e.g. ...
36 views

Security proof regarding a zero-knowledge counterexample that is secure in the stand-alone model but insecure in the UC model

Background The following zero-knowledge (ZK) counterexample is described in Canetti's work [Security and Composition of Cryptographic Protocols: A Tutorial, page 26] to show that there exists some ...
68 views

Product of secrets in multi-secret sharing schemes (aka packed secret sharing schemes)

The question is related to the multi-secret sharing scheme described in the following paper: [FY92] Matthew K. Franklin, Moti Yung: Communication Complexity of Secure Computation (Extended Abstract). ...
77 views

Are there secure MPC schemes that support uneven load balancing between the parties?

In a scenario in which some of the parties have more data / compute power / trust reputation (or other meaningful properties) than other parties - are there known methods to do secure multiparty ...
137 views

Is there any OPRF (oblibivious pseudo random random functions) between one receiver (1 input) and n senders (n inputs)? any references to read?

I am looking for some references for multi-party / distributed Oblivious pseudorandom Functions. I found two party OPRF protocols between a sender $S$ and a receiver $R$ for securely computing a ...
51 views

32 views

Strategies for fast integrity attestation over multi party computation for large messages

I am looking for ways to efficiently perform integrity attestation over large messages using multi party computation. While, hashing (SHA1, 256...) is one alternative but it's painfully slow and grows ...
68 views

Necessity of Randomness when Privately Computing a Sum

I want to show that no 1-private deterministic protocol exists for calculating a sum of $n \geq 3$ parties (within the realms of Perfect rather than Computational Security). I'm having trouble showing ...
35 views

Computationally secure ORAMs with O(lg n)-bit words: shouldn't they fail with $n^{-O(1)}$ probability?

Virtually all "hierarchical" Oblivious RAMs use "cryptographically secure" hash functions to determine the position of an item at a given level; and implicitly assume (as can be evinced from the cost ...
191 views

Rewinding techniques with some examples

I'm aware of these posts: What is a "rewinding argument"? Random oracle model proofs and programmability But I think, some concrete examples are missing. I need to know how exactly ...
92 views

Are there any information-theoretically secure verifiable secret sharing protocols with t=n?

Disregarding matters such as efficiency and round complexity, can verifiable secret sharing be done in a way such that the secret cannot be decoded unless you have all n shares, and that this ...
160 views

40 views

Examples of oblivious transfer protocols secure under stronger security assumptions than semi-honest model?

The question is basically stated on the title. I have done some introductory reading on Oblivious Transfer and most of them are secure in the semi-honest model. Are there any protocols that are secure ...
38 views

93 views

Understanding multiplication of Shamir secret sharing during threshold (EC)DSA signing

I have been looking at the threshold (EC)DSA schemes for honest majority by Gennaro et al. https://www.sciencedirect.com/science/article/pii/S0890540100928815. In the scheme, there are steps where we ...