Previously, any project that wanted to transfer assets or data between Avalanche Subnets had to deploy and manage its own bridges to accomplish this goal.
To understand what AWM really works, first we must understand two things:
BLS digital-signatures
BLS digital signature, also known as Boneh–Lynn–Shacham, is a cryptographic signature scheme that allows a user to verify the authenticity of a signer.
One of the scheme’s key features is “signature aggregation,” which allows multiple signatures computed using different public keys (for different messages) to be combined into a single signature.
The scheme supports batch verification, where a set of multi-signatures can be verified as a batch faster than verifying them one by one.
Aggregation can be done publicly by simply multiplying the signatures, even after all of the signatures have been generated and the signers are no longer available.
This means that all the signers associated with a multisig address can simply send their signatures to a single party, who aggregates them into a single signature. There is no need for interaction, and all parties do not need to be online at the same time.
Public Key Aggregation
With an aggregated public key multi-signature scheme, the signature and corresponding public keys are as small as the underlying signature scheme, resulting in smaller blockchains.
In other words, a multi-signature scheme enables a group of signers to create a combined signature on a common message that is more compact than a collection of distinct signatures from all signers.
A verifier can check if every signer in the group participated in signing using this signature and the list of signers’ public keys.
How does Avalanche Warp Messaging work?
It enables Subnet Validators to collectively create a BLS Multi-Signature that certifies the legitimacy of any message (such as a transfer, contract data, etc.) that can be verified by any other Subnet.
This eradicates the need for Subnets to communicate and exchange updates about changes on their respective validator sets on a regular basis in order to continue validating messages.
Lead Solidity Developer at Kingdom Studios, Magnus Ironroot, said: “The Avalanche Warp Messaging gives yet another reason to build in the Avalanche ecosystem, enabling secure transmission of messages between Avalanche Subnets with developer-friendly tooling.”
Subnets may choose how to fill up this set of message bytes, allowing them to choose which Subnets to accept messages from and to indicate the weight a BLS Multi-Signature must have to be regarded as valid.