Implementation

Danake is implemented in Rust. The proof statements are written declaratively, using the zkp crate to automatically derive implementations of each proof statement. Rangeproofs are provided by the bulletproofs library, and they are composed with the other proof statements using Merlin transcripts. Both the Bulletproofs and the Schnorr proofs generated by zkp use the ristretto255 group, as implemented in curve25519-dalek.

Implementation status

Core functionality

  • Wallet functionality
    • keygen
    • issuance
    • rollover
    • topup
  • Token functionality
    • keygen
    • purchase
    • rollover
    • spend
  • Proper transcript design
  • Nullifier queries (double-spend prevention)
  • Epoch-aware keygen (should be able to generate keys for every epoch from a single root key)
  • Simulator
    • Arbitrary impl generating a stream of protocol events
    • proptest checker for event streams

Integrations

These would make Danake more practically useful:

  • danake-proxy: reverse proxy that sits in front of an HTTP service and meters an HTTP API.