Reparo for Tezos

Greetings Tezos Community,

We are the authors of Reparo which is a publicly verifiable repair layer for any blockchain. Reparo can easily be integrated into an existing blockchain system and does not require any additional cryptographic capabilities from the underlying blockchain. For more details, please check the blog post and the full paper. You can find formal definitions, security analysis, algorithms and the performance analysis in the paper. We would like to start a discussion thread to adopt Reparo into Tezos.

For instance, Reparo powered Tezos can benefit from the following (and possibly more) improvements:

  • With Reparo, one can easily fix bugs in smart contracts and redact sensitive/private information from the blockchain.
  • Reparo enables efficient repair of (multiple) states which is important for a self-amending protocol system like Tezos.
  • Instead of a redundant 4 phase voting approach, move to a two-phase voting approach (still conservative but secure)
    • In the first phase of voting, propose a change.
    • If there are Q votes on the proposal, move the proposal to the test-net for d cycles, where d = c quarters or c*32768 blocks
    • Use the second phase of voting to determine the upgrade from test-net to the main-net.
    • Make a vote as an on-chain transaction, so that we can add public verifiability for the repairs.

We look forward to your feedback and suggestions. Please contact us at for any clarifications/questions about the protocol, algorithms or instantiations.

Doesn’t this violate the very nature of blockchain technology in that everything is immutable?

On a high level, the blockchain is still immutable. We use the immutable blockchain for the participants to agree on the new state. It is mutability by consensus. It is analogous to protocol amendment by agreement.