Blockstream Researchers Introduce New Multisig Standard Dubbed ROAST

Blockstream has announced the rollout of a new multi-signature standard called Robust Asynchronous Schnorr Threshold Signatures (ROAST). ROAST is designed to function as an improvement to the Flexible Round-Optimized Schnorr Threshold Signatures (FROST) threshold signature scheme, according to a blog post on May 24, 2022.

Blockstream Launches ROAST

Blockstream, a blockchain technology company dedicated to developing Bitcoin-focused products and services, has released a new proposal for a multisig standard that comes without the limitations of existing multi-signature technologies such as FROST. 

Per a blog post by Blockstream, the new multisig standard known as (Robust Asynchronous Schnorr Threshold Signatures) ROAST, is a result of a research collaboration between the firm’s researchers and experts from across the world including, Tim Ruffing (Blockstream), Viktoria Ronge (Friedrich-Alexander University Erlangen Nuremberg), Elliot Jin (Blockstream), Jonas Schneider-Bensch (CISPA Helmholtz Center for Information Security), and Dominique Schroeder (Friedrich-Alexander University Erlangen Nuremberg).

For the uninitiated, multi-signature (multisig) simply refers to requiring more than one key (signature) to authorize a transaction on the  Bitcoin network, rather than a single signature from one key. 

Multisig technology has a number of use cases including the elimination of a single point of failure which makes it more difficult for a wallet to be compromised, dividing up responsibility for bitcoin ownership among multiple parties, and more.

Automating Multisig Transactions with ROAST

Despite the several benefits of existing multisig technologies such as FROST, they come with one huge flaw: the process is not automated, meaning that the absence of a signer brings the entire transaction to a halt. A transaction could also fail if a signer decides to act maliciously by inputting an incorrect signature. 

However, with ROAST, transactions between the Bitcoin network and Blockstream’s Liquid sidechain will be more efficient, automated, secure, and private. The team has also made it clear that ROAST is capable of handling larger signer groups even if all the parties may not be present in the same geographical location.

Blockstream wrote:

“ROAST is a simple wrapper around threshold signature schemes like FROST. It guarantees that a quorum of honest signers, e.g, the Liquid functionaries, can always obtain a valid signature even in the presence of disruptive signers when network connections have arbitrarily high latency. Our empirical performance evaluation shows that ROAST scales well to large signer groups, e.g., 67-of-100 setup with the coordinator and signers on different continents.”

“Even with 33 malicious signers that try to block signing attempts (e.g. by sending invalid responses or by not responding at all), the 67 honest signers can successfully produce a signature within a few seconds,” the team added. To get an in-depth introduction and description of ROAST, read the 13-page research paper.

Blockstream remains one of the projects that have made significant contributions toward the continued success of the Bitcoin network over the years.

In May 2020, the Canada-based company launched the Blockstream Satellite 2.0. To make it possible for users to synchronize the entire bitcoin node even without internet connectivity, enabling people in areas without reliable internet to still transact with the flagship cryptocurrency.

As reported by crypto.news last April, Blockstream joined forces with Jack Dorsey’s Block (formerly Square) and Tesla to launch a new solar-powered bitcoin (BTC) mining facility with 3.8 megawatts (MW) of electrical power.