Mithril

Mithril is a research and engineering effort carried out by IOG to boost the efficiency and speed of data synchronization, state bootstrapping, and trust issues in blockchain applications. As part of the Basho development phase, Mithril is now in development to be applied as a protocol on Cardano.

Data synchronization and state bootstrapping are integral to ensuring the accuracy of operations on the blockchain. For certain messages or actions, it is important that a particular number of stakeholders provide their cryptographic signatures.

For the base case, we go from a linear number of participants (without Mithril) to a logarithmic one (with Mithril), which is more efficient. This means that the higher the number of participants who need to agree on operations, the more complex it becomes to efficiently aggregate their signatures. In a base scenario, to presume a signature that talks for the majority of stakeholders, every stakeholder needs to sign the appropriate individual message. This results in delays in terms of scalability and speed.

Mithril has been designed to address these issues and to ensure efficient data and state synchronization while preserving rigorous security settings. Simply put, Mithril allows a variety of applications to work faster on the blockchain. Mithril's aggregation does not require signers to coordinate with other signers to produce signatures: they can sign independently and anyone can perform the aggregation, even at a later time. The signature scheme also lets different stakeholders validate only a given checkpoint of the chain (where 'checkpoint' is a state of the chain at some point in time, plus Mithril proofs to support that) without going through the whole transaction history of the given state. This results in fast chain state bootstrapping,

Overall, the protocol is also beneficial for light client applications like light wallets that need to work fast without a full chain synchronization. Mithril signatures can be also useful for lightweight tally verification, or cryptocurrency governance decision making. ​​When applied to full node clients like Daedalus, Mithril can boost full node data synchronization ensuring speed and decreasing resource consumption.