Combining privacy with stablecoin+RWA assets have a promising future with JAM rollups!
I’ve been building a PoC JAM service around Zcash NU7 (which introduce shielded assets) and was happy to discover your post. A year ago, I thought it was necessary to have additional host functions to support verify + hashing, but actually … polkatool is reasonably good enough to compile bits of rust into PVM just fine, such that when you use a recompiler your zkproof verifications that take at most 50ms use up 75MM-100MM pvm gas.
Since people are always inventing new proof systems, hashing methods, etc. I have come to appreciate the wisdom of the minimalist view of having compiled PVM do all the work – luckily Rust is the language of choice and polkatool supports JAM PoC. We’ve reduced this to actual practice, though it just a PoC effort right now.
Once builders get the hang of building JAM rollup services (using refine for stateless verification and deciding exactly where your nullifier/utxo/roots state lives in JAM State/JAM DA vs builder side), it becomes clear how much more difficult it is to develop privacy services in unfactored ecosystems (e.g. zcash) and how much easier it is to develop and iterate in the JAM framework which factors it out nicely.