By Claudio Orlandi, Associate Professor and Chief Cryptographic Protocol Designer at Partisia

In previous blog posts we explained how secret-sharing is a useful tool for performing secure Multiparty Computation (MPC) when we can assume that a majority of the participants are honest.

However, there are many situations in which it is simply not realistic to assume that a majority of the participants in a protocol are honest. …

By Ivan Damgård, Professor and Chief Cryptographer at Partisia

In cryptography, a circuit is a way in which a computation can be represented, consisting of operations on bits. A garbled circuit, however, is a method to encrypt a computation that only reveals the output of the computation itself, without giving away anything regarding the inputs or the values of the computation. In this blog post I will explain garbled circuits, which was the very first approach used in secure computation, and it was suggested by Andrew Yao in the late 1980s.

Before discussing the computation part, let’s talk about encryption…

By Ivan Damgård, Professor and Chief Cryptographer at Partisia

Oblivious transfer (OT) is a fundamental tool in cryptography. In this blog post, I will explain what OT is, what it can be used for, and how it can be implemented.

In a nutshell, OT can be thought of as a very strange communication channel. It works as follows: a sender, Alice, can send two bits, b0 and b1, to a receiver, Bob, via OT. However, only one of the two bits will make it to Bob and he can choose which of the bits he wants to receive. …

Zug — 17 May 2021 — Partisia Blockchain, the Web 3.0 public blockchain built for trust, transparency, and privacy has announced it has raised over $20m following its latest funding round led by Ausvic Capital, P2P.org, Kosmos, and Bitscale, as well as other key players including Crypto Bazar Capital, CRT Capital, Gate.io Labs, and Insignius Capital.

Partisia Blockchain’s cutting-edge solution to the internet’s confidentiality and privacy challenges represents the first successful complete integration of blockchain technology with another commercial grade distributed cryptography, Secure Multi-Party Computation (MPC). …

By Jesper Buus Nielsen, Professor and Chief Cryptographic System Designer, Partisia

This blog post will introduce a cool MPC trick, known as Beaver Triples. It was Invented in 1991 by Don Beaver [1], it has multiple uses in MPC. In this blog I will explain how to use it for preprocessing and how to get an “almost asynchronous” MPC with the same security enjoyed by synchronous MPC. I will also explain the difference between synchronous and asynchronous MPC.

By Ivan Damgård, Professor and Chief Cryptographer at Partisia

One of the main tools offered by modern crypto and multiparty computation (MPC) in particular is secret-sharing. This concept was explained in a previous blog post on Secret Sharing. To recap:

A so-called dealer has a secret number s. She does some computation involving various random choices and produces an output as a set of n shares s1,…,sn. The idea is that you can distribute these shares (privately on a secure connection) to n parties. …

By Claudio Orlandi, Associate Professor and Chief Cryptographic Protocol Designer at Partisia

Last week’s blog titled “Secret Sharing” explained how to securely compute on secret data using a special technique known as “replicated secret-sharing”. Informally, we argued that using this technique, no single participant will ever learn any of the secrets they are computing on.

However, we have not yet defined what secure means in this context. Since this blog series is about secure multiparty computation, this post will focus on some of the most common taxonomy for security levels in multiparty computation, with a particular focus on active security.

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By Claudio Orlandi, Associate Professor and Chief Cryptographic Protocol Designer at Partisia

This is the first in a series of blog posts, titled ‘MPC Techniques’, which we will be publishing every week for the next 9 weeks. In each blog, we will be presenting some of the basic techniques which can be used to implement MPC, which will likely be of interest to developers and those with a mathematical or technical background. This first chapter focuses on secret-sharing.

As Ivan has explained in a previous post titled, ‘Multiparty Computation: The beacon of privacy solutions explained’, secret-sharing is one of the…