Multiverse Threshold Signatures and Permissionless Oracle Networks

Paper Presentation

The year is 2035, and your business relies 100% on decentralized systems to manage sensitive data. As threshold signature schemes struggle to manage the complexity of securing it, a groundbreaking approach simplifies and secures data management across multiple decentralized networks: Multiverse Threshold Signatures (MTS).

You can finde the paper free of charge here

In this blog post, we’ll explore how MTS works, why it’s a game-changer for Oracle Networks (Chainlink anyone?) but also for any businesses handling sensitive information

And. This 2023 paper is only the stepping stone for a brand-new breakthrough I’ll be presenting next week. LFG!

The Problem with Traditional Threshold Signatures

Traditional threshold signatures struggle with scalability in dynamic decentralized systems, leading to inefficiencies and vulnerabilities as key and signature sizes grow with network complexity.

For those who don’t know, threshold signatures are the cornerstone of security (see here and here). They allow a group of parties to collectively sign a message, ensuring that no single entity has complete control. However, as systems grow more complex, traditional threshold signatures face significant challenges.

Let’s see the problem. Consider a decentralized oracle network like Chainlink, which handles thousands of data feeds across hundreds of nodes. Each node must manage multiple keys and signatures for different “universes”: groups of nodes with specific security thresholds. This leads to a linear increase in key size, signature size, and computation time.

For example, in a network with 2000 nodes and 100 universes, each node must generate 100 partial signatures for every message. The result? Over 1 GB of network traffic for a single message, making the system impractical for real-world use.

Managing nodes’ keys is a real problem when each node can potentially be part of 1000+ networks (source)

The main issue is scalability: Traditional threshold signatures were designed for static environments where the set of signers and thresholds remain fixed. But in today’s dynamic, decentralized systems, verifiers often have different trust levels and security requirements. This mismatch creates inefficiencies and vulnerabilities that can compromise the entire network.

So, traditional threshold signatures struggle to scale in decentralized systems, leading to inefficiencies and increased vulnerability. How to fix?

Multiverse Threshold Signatures (MTS)

To address these challenges, Baird et al. have developed Multiverse Threshold Signatures (MTS), a novel approach that allows multiple groups with their own set of signers, weights, and security thresholds to coexist seamlessly.

Here is what MTS brings to the table: non-interactive setup, compact keys, and reusable partial signatures. Everything is based on BLS signatures, so it is perfect for chains like Ethereum. An ideal cocktail for decentralized systems.

This is a good primer on BLS and how to use them in Ethereum. There is math, but it worths it. source

Here’s how it works: Each party in the multiverse holds a (constant-sized) key, regardless of how many universes it belongs to. When a message needs to be signed, each party generates a single partial signature that can be reused across multiple universes. An aggregator then combines these partial signatures into a compact aggregate signature specific to a particular universe. As a result, the system that is both efficient and secure, even in large, dynamic networks.

For example, in a network with 2000 nodes and 100 universes, MTS reduces the bandwidth requirement from 1 GB to just 1 MB per message. Each node only needs to store a 128-bit key, and the setup process is entirely non-interactive, allowing nodes to join or leave universes without disrupting the system. That means permissionless oracle networks!

Technically, Chainlink is not permissionless. You need authorization to enter. Not good if you are still a boomer that caresa abot decentralization, privacy and those old cypherpunk ideals (source)

In short, MTS introduces a scalable, efficient, and secure solution for decentralized systems, enabling multiple universes to coexist without compromising performance. Why caring?

The Practical Benefits of MTS for Businesses

You may not own Chainlink, but if you’re considering decentralizing your business, you’ve likely wondered about potential inefficiencies. Rest assured, your doubts are about to be resolved.

Whether you’re managing financial transactions, military communications, or healthcare records, MTS offers a way to enhance security while reducing operational overhead.

One of the most significant advantages is bandwidth efficiency. In traditional systems, the sheer volume of data generated by partial signatures can overwhelm network resources. MTS drastically reduces this burden, ensuring that your network remains fast and responsive even as it scales.

Another key benefit is cost efficiency. In blockchain-based systems, every operation (ex: verifying a signature) incurs a cost. MTS minimizes these costs by producing compact signatures that are quick to verify. For instance, in a decentralized oracle network, MTS reduces the gas cost for signature verification by a factor of 3.38 compared to traditional schemes. This can translate into significant savings, especially for businesses that handle large volumes of transactions.

Less operation, less storage and more speed = profit!

Finally, MTS offers flexibility. In a multiverse, each universe can have its own security threshold and set of trusted nodes. This allows businesses to tailor their security policies to specific use cases, whether it’s a high-stakes financial transaction or a low-latency sports betting application.

In summary, MTS provides businesses with a cost-effective, flexible, and scalable solution for securing sensitive data in decentralized systems. Now let’s see specific use cases.

Real-World Applications of MTS

So far, I’ve defined a “universe” as a group of signers for a specific purpose. While this concept might be clear in the context of Chainlink, it may not be as straightforward for other businesses. This section will break it down further.

In finance, a “universe” could be a specific group of authorized signers involved in cross-border transactions, such as compliance officers, financial institutions, and auditors. A different universe for each pair of nations or regions. Since universe participants would likely overlap, MTS (Multiparty Threshold Signatures) would efficiently help to ensure that only these designated parties for each cross-border pair can approve payments, reducing fraud risk and enhancing trust.

In healthcare, a “universe” might consist of healthcare providers, insurance representatives, and compliance officials managing patient records across institutions. Different universes deal with different healthcare providers or institutions. MTS would ensure that only authorized personnel can access sensitive information, maintaining patient privacy and regulatory compliance.

In the military, MTS can be used to secure communications between different units, ensuring that only authorized personnel can send or receive critical information. This is particularly important in high-stakes environments where the integrity of communications can mean the difference between success and failure.

Even in supply chain management, MTS can play a crucial role. By ensuring that only authorized parties can sign off on shipments, MTS can help prevent fraud and ensure the integrity of the supply chain.

In summary, MTS has wide-ranging applications across industries, from finance and healthcare to military and supply chain management and more.

Conclusion: Embracing the Future of Security

Data is more valuable and vulnerable than ever. Businesses should move from a centralized security approach to a decentralized one. Multiverse Threshold Signatures offer a way forward, providing a scalable, efficient, and secure solution for managing sensitive information in decentralized systems.