That single sentence from calle (npub12rv…85vg) , the creator of the Cashu ecash protocol, just unlocked the biggest scaling breakthrough Bitcoin has had in years.
The reason ecash scaling has been limited to small community mints is because running a larger one makes you a money transmitter. Calle's solution: non-custodial Cashu mints running inside hardware enclaves. The bitcoin keys are generated inside the enclave and never leave it. The mint operator literally cannot access them. Even with full admin access to the server, they cannot steal the bitcoin.
Remove the custodial barrier and the design space explodes. Public organizations, businesses, community groups can all run mints without taking on custodial liability.
The security model is battle-tested. ACINQ already uses the same approach with AWS Nitro Enclaves to protect their massive Lightning node holding hundreds of millions in BTC.
The historical lineage is what gets me. In 2004, Hal Finney built RPOW (Reusable Proofs of Work) using IBM's secure cryptographic coprocessor. The server was "more trustworthy than an ordinary bank" because the hardware itself guaranteed the software hadn't been tampered with. Finney's system wasn't tied to an existing currency. Calle's is.
Cashu ecash backed by Bitcoin, running in a modern enclave, is RPOW's spiritual successor. Except this time it's built on the hardest money in human history.
The honest caveats: this doesn't reduce risk to zero. The biggest practical risk is denial of service. The operator could turn the mint off. But since they can't steal the bitcoin, there's no financial incentive to do so.
We're getting closer to having everything we want: privacy, ease of use, and reduced custodial risk, all on Bitcoin rails.
Hal Finney's vision, finally realized.
