Offshift Dev Update Mid October 2022: MPC Ceremony


As Offshift Core places the finishing touches on the feature-complete Offshift anon Testnet, the team also has its sights set on the necessary preparations to make for a successful mainnet launch. In order to launch a robust Layer 1 platform with full protections for user anonymity, the Offshift anon mainnet launch must be preceded by a Multi-Party Computation (MPC) Ceremony.

In this biweekly development update, we introduce the Offshift anon MPC Ceremony, its role in ensuring decentralized protocol operations, and most importantly, how you can get involved and contribute. But first, have a look at the features the Offshift Core dev team completed in the first half of October.

What We’ve Accomplished

  • Support for multiple tokens and denominations
  • Support for withdrawals to any address
  • Vault tab to display user deposits (per wallet address)
  • Arbitrary Simple Shifting amount (from minimum of 0 to maximum of user’s balance)
  • Custom password upload in the Settings tab

Now, without further ado, let’s dive into what’s ahead for Offshift anon and its MPC Ceremony just around the corner.

zkSNARKs & MPC Ceremonies

Today, Zero knowledge proofs have secured their position as cryptocurrency’s most potent and promising instruments for developing privacy-centric protocols. Principally, zk-proofs allow one party to prove to another that some statement is true – that is, valid – without revealing any further information as to its contents. In the nascent blockchain landscape of 2022, computational capacity is limited, and three different zero knowledge implementations stand at the forefront of the crypto space, each offering a different set of strengths and limitations.

zkSNARKs have long been and continue to be the leading implementation in the zero knowledge domain for their unrivaled succinctness and efficiency. Simply put, SNARKs don’t run up the meter on Ethereum users, who are dealing with a very limited environment on Ethereum Layer 1 – at least, until the Verge gets underway. Once a privacy solution powered by SNARKs is live and running, it is extremely secure, and provides comprehensive protections for user privacy. However, zkSNARKs require a specialized setup process called an MPC Ceremony – more on this in a moment.

zkSTARKs and Bulletproofs, on the other hand, while far more demanding in the computation department, require no MPCs of any kind. It is for this reason that Offshift Core employed Bulletproofs to develop zkAssets for its confidential on-chain synthetics platform, Offshift zk.

MPC Ceremonies: The Backstory

Unlike STARKs and Bulletproofs, zkSNARKs rely on a Common Reference String (CRS) that is used as a public parameter for proof and verification processes in a specific circuit. As the protocol depends on its CRS to function, the CRS must be generated in advance by a trusted party. Since a trusted party then may hold onto the information used to generate the CRS, it could theoretically use that information to generate fraudulent proofs, thus threatening to compromise the integrity of the protocol.

In order to mitigate any such risks, leading cryptographers in the zero knowledge community developed a secure, participatory methodology for generating a CRS that involves a large group of individuals. This process is called a Multi-Party Computation (MPC) Ceremony, where a number of individuals contribute randomness in the CRS generation process. During an MPC Ceremony, each participant iteratively contributes to the generation of the CRS, and subsequently passes the partially constructed MPC (termed the “transcript) to the next individual in line.

Here’s the good news: in an MPC Ceremony, only 1 honest participant is needed to ensure the security of the platform, so as additional contributors join the ceremony, the likelihood of collusion becomes arbitrarily close to zero. And, if you want absolute zero – no problem! All you have to do is join in yourself, and discard and destroy the information you contribute to the generation of the CRS – it’s that simple.

The Offshift anon MPC Ceremony

In our commitment to decentralization, Offshift Core will be holding a Powers of Tau MPC Ceremony to best protect the integrity of the Offshift anon platform. The Powers of Tau model is the leading ceremony for zkSNARK CRS generation, and one that has been successfully conducted by leading cryptocurrency projects such as Filecoin and the Zcash Sapling Network. The Powers of Tau model facilitates a continuous MPC Ceremony where participants do not need to be available or online at all times, and supports potentially thousands of participants.

So, in addition to staying tuned for the highly anticipated release of the feature-complete Offshift anon Testnet, keep an eye out for upcoming announcements for the official Offshift anon MPC Ceremony. We’re calling all PriFi Pioneers new and old to join us in getting prepared for a powerful, principled, and integrity-driven mainnet launch.

To stay up-to-date and in-the-know on platform development and all the latest news, follow us on Twitter, join our official Telegram, and check in here on the official Offshift Blog.