The recent Cortina network upgrade introduces a groundbreaking new feature: Cross-Subnet Messaging, powered by Avalanche Warp Messaging (AWM) technology. 

This cutting-edge technology is designed to seamlessly facilitate communication and collaboration across multiple subnets, creating an interconnected environment for cross-chain interactions.

With this innovation, any Subnet on the Metal Blockchain gains the ability to transmit arbitrary messages to any other Subnet in just seconds, without the need for a trusted relayer or bridge. Instead, the validators of the Subnet directly send and receive the messages.

Now, with Cross-Subnet Messaging, the Metal Blockchain opens up new avenues for decentralized applications and protocols to interact, collaborate, and leverage each other's strengths. The rapid and secure exchange of data and assets across different subnets fosters a dynamic and robust ecosystem, empowering users with greater possibilities and opportunities.

Interoperable Subnets

The power of Interoperable Subnets, fueled by Cross-Subnet Messaging, unleashes a wealth of opportunities for developers, businesses, and end-users alike.  By facilitating the deployment of diverse subnets, each tailored to specific use cases, Metal Blockchain creates an environment conducive to fostering an ecosystem of application-specific blockchains.

Traditionally, app chains in the siloed blockchain landscape encounter liquidity constraints and struggle to cultivate the network effect. The network effect, where the value of a product increases as more people use it, is crucial for sustained growth and adoption. 

However, through Cross-Subnet Messaging on the Metal Blockchain, subnets can flourish and seamlessly interact with one another. This collaboration enables the sharing of users and liquidity, unlocking the true potential of the network effect.

The interconnection between subnets creates new synergies, benefiting developers, businesses, and end-users alike. Developers can focus on building specialized networks that cater to distinct use cases, ensuring optimal performance and tailored experiences. Businesses can leverage these interconnected subnets to access a diverse user base and foster the growth of their services or applications.

For end-users, this could provide unparalleled access to a wide range of decentralized services and applications delivered by these specialized networks. This diverse array of options allows users to find solutions that precisely meet their needs, promoting convenience and user satisfaction.

Cross-Subnet Messaging Use Cases

Thanks to the capabilities of Cross-Subnet Messaging on the Metal Blockchain, various applications and platforms can harness its inherent cross-chain communication features for their specific use cases:

DeFi Protocols: DeFi protocols stand to revolutionize their capabilities by harnessing the power of Cross-Subnet Messaging. This cutting-edge technology enables seamless exchange of tokens and data between subnets, fostering the creation of diverse and liquid markets for users, and significantly enhancing the overall DeFi landscape.

With Cross-Subnet Messaging, subnets can evolve into liquidity hubs, aggregating value from various interconnected subnets. This creates a dynamic and interconnected DeFi ecosystem, enabling efficient capital allocation and maximizing opportunities for users seeking diverse investment options.

Vault-focused subnets gain immense potential through cross-subnet yield strategies. By implementing these strategies, users gain broader access to yield opportunities beyond their local subnet. This innovative approach empowers users to optimize their yield farming strategies, maximizing returns and portfolio diversification.

Enterprise Deployments: Enterprises can utilize Cross-Subnet Messaging to facilitate secure information and transaction sharing between distinct permissioned subnets, enhancing privacy and efficiency in their operations.

Decentralized Identity and Reputation Systems: With Cross-Subnet Messaging, establishing decentralized identity and reputation systems becomes a reality. Users can securely manage their identities across various subnets, enhancing privacy and control over personal data. This innovative approach promotes self-sovereign identity, where users have full authority over their digital personas, leading to greater data ownership and protection.

Private or compliant subnets can leverage Cross-Subnet Messaging to verify new users based on their credentials from other subnets. This streamlined verification process ensures a seamless onboarding experience for users, while maintaining privacy and adhering to compliance requirements. The ability to verify users across multiple subnets enhances the overall efficiency and trustworthiness of the identity verification process.

Data Feeds and Oracles: Subnets can seamlessly offer data feeds and oracles to other subnets in need of these services. This efficient data exchange ensures a consistent and accurate flow of information, vital for reliable decision-making and smart contract execution. The decentralized nature of this data sharing fosters transparency and eliminates single points of failure, enhancing the overall security and resilience of the system.

Gaming Platforms: Gaming ecosystems can develop cross-game assets and experiences that span multiple subnets, opening up new opportunities for gamers and enriching the gaming experience.

Cross-Subnet Architecture

At the heart of the Cross-Subnet Messaging’s design is a hierarchical approach, where subnet-level nodes act as efficient message brokers within the platform. These message brokers follow a publish-subscribe pattern, enabling messages to be published to specific channels, and subscribers receive updates relevant to their particular interests from these channels. This architecture ensures efficient and targeted communication between different Subnets.

Cross-Subnet Messaging’s innovative use of Merkle trees ensures secure and efficient message authentication. By employing this approach, it guarantees data integrity and reliable message delivery across the network, even as more subnets become connected.

In addition, Cross-Subnet Messaging leverages the power of Boneh-Lynn-Shacham (BLS) multi-signatures. This cryptographic scheme allows multiple parties to collectively produce a single, compact signature, efficiently verifiable using their public keys. 

By employing BLS multi-signatures, Cross-Subnet Messaging enables groups of validators to sign messages collectively with a single signature, making it easily verifiable for anyone possessing the validators' public keys. This streamlined process enhances the overall efficiency and security of cross-chain communication within the Metal Blockchain ecosystem.

Cross-Subnet Messaging incurs minimal fees, as only a small amount of METAL is needed to generate a BLS signature. However, additional fees may be imposed within subnets.

Cross-Subnet Messaging Compatibility

Cross-Subnet messaging is currently compatible with the Golang and Rust VM SDKs, enabling VM builders to leverage its functionality. Subnet builders now have access to powerful tools such as Elastic Staking, which enables the staking of custom tokens to validate their subnet, and the Rust VM SDK, facilitating the development of blockchain solutions entirely in Rust. With the addition of Cross-Subnet Messaging, subnets can now seamlessly exchange messages, further expanding their capabilities.