Protocol Labs Research
2022-07-21 / News, Grants
The Pikachu RFP: Checkpointing Filecoin onto Bitcoin

Blockchains based on a reusable resource (such as proof-of-stake or proof-of-space) are not as secure as those based on proof-of-work. Specifically, they are vulnerable to long-range attacks (LRA), where an adversary can create a long fork very cheaply.

With Project Pikachu, we proposed a checkpointing mechanism that allows Filecoin to leverage the security of proof-of-work by anchoring state onto the Bitcoin blockchain. In the case of long-range attacks, the Bitcoin chain can be used to determine the honest chain. In short, we came up with a design that leverages Schnorr threshold signatures supported by the 2021 Bitcoin Taproot upgrade.

However, our prototype solution does not scale to the full Filecoin network, which features thousands of miners/validators. We’re therefore launching a new funding programme to scale checkpointing to large blockchain networks. Under RFP-012, we invite proposals to address checkpointing scalability, including:

  • Non-interactive DKG schemes
  • Weighted threshold DKG and Schnorr signing schemes
  • Parallelized/nested DKG schemes
  • Efficient share aggregation mechanisms
  • Sampling mechanisms

Accepted proposals will receive up to $100,000 in funding. The work, as usual, must be released under an open-source license and may find usage in other blockchains or systems. This call will close on September 30, 2022 or earlier if awarded.

We encourage interested researchers to reach out to us using our discussion forum or by visiting #consensus in the Filecoin Slack workspace. For formal questions, please email Submit your proposal using our application management system at