Ashigaru Whirlpool builds upon the original architecture and, at its core, does not deviate from the structured approach to the coinjoin cycles that was designed by TDevD and ZeroLeak of Samourai, and LaurentMT of OXT. Nevertheless, a number of the aspects of the protocol have been updated by the Ashigaru Open Source Project as summarized below.

Ashigaru Whirlpool is Tor only. There are no clearnet connections possible to ensure coinjoin participants have no concerns about a malicious coordinator linking inputs to outputs via IP addresses, or being able to perform wallet address clustering.

Furthermore, we have enhanced user network anonymity by building in Tor identity isolation to ensure coinjoin participants’ session IDs cannot be used by the coordinator to link activity from the input registration stage to the output reveal address stage of each coinjoin transaction cycle.

As our implementation is exclusively Tor, there is no dependency on DNS and our coordinator location is not exposed. The ability for us to spin up new Ashigaru Whirlpool coordinators for clients to automatically connect to is a critical part of our decentralization strategy. Our coordinator has been further modularized by eliminating the dependency of RPC connections to a local full node. The coordinator can therefore be connected to any Dojo full node over Tor, enabling faster deployment and recovery, minimal hardware resource requirements, and greater jurisdictional flexibility.

The protocol necessitates the tracking of all Transaction Zero (Tx0) IDs together with the TxIDs of eligible remixers in a database. This is to ensure only UTXOs which have paid the Anti-Sybil fee may participate in coinjoin cycles. Decentralizing these databases is a key focus for us in the future. Nevertheless, we have reduced the impact of a loss of this database by ensuring only public keys for receipt of Anti-Sybil fees are kept locally to the coordinator, and private keys held offsite.