Spark is an off-chain scaling solution that builds on top of Statechains to enable instant, extremely low fee, and unlimited self-custodial transactions of Bitcoin and tokens while also natively enabling sending and receiving via Lightning.

Spark is not a rollup, nor a blockchain. There are no smart contracts nor VM. Spark is native to Bitcoin and its payments-focused architecture, enabling on-chain funds to be transacted at any scale, with near-instant speeds, and at virtually zero cost.

At it’s core, Spark is a simple shared signing protocol on top of Bitcoin. It operates as a distributed ledger. There are no bridges, external consensus, or sequencers. Users can enter and exit the network freely, with funds always non-custodial and recoverable on L1 via a unilateral exit which depends on Bitcoin and no one else. Transactions on Spark happen by delegating on-chain funds via the shared signing protocol.

Like the Lightning Network, Spark transactions work by delegating ownership of on-chain UTXOs between parties. The key difference: Spark introduces a set of signers, called Spark Operators (SOs), responsible for helping sign transactions as they happen. SOs cannot move funds without the users, who are required participants in any transfer. On L1, Spark state appears as a chain of multi-sigs, secured by users and SOs. On L2, it operates as a tree structure, mapping transaction history and balances in real time. Simple, fully native to Bitcoin, and open-sourced.

For a system that scales Bitcoin as effectively as Spark does, it achieves the maximum possible level of trustlessness. Specifically, it maintains 1/n trust assumptions or minority/n depending on the setup. To learn more about the trust assumptions, read our trust assumptions page.

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Key Features

We built Spark from first principles. It’s designed to deliver an exceptional payment UX that’s as trustless as possible while making sure we respect our core Bitcoin roots.