feat(approach): enshrined private transfers

[RogerPodacter]

What are you adding?

• Vendor/Protocol
• Enterprise Use Case
• Update to existing content
• Other

Description

New approach doc: enshrined private transfers. Describes an intent-transaction standard for wallet-authorized private transfers, a Privacy RPC server-side proving bridge, and an L1 system contract upgradeable only by hard fork. Includes optional compliance layers (proof of innocence, issuer viewing keys). Based on this article, with a live demo and draft spec.

Checklist

• I've checked this doesn't duplicate existing content
• All links work
• Info is accurate

[Meyanis95]

Thanks for this. The spec and live demo links are a great find.

A couple of things before we can merge:

• What you've described (native shielded UTXO pool, intent-transaction standard) is really a pattern; in the current taxonomy, it's a building block, not a full approach to a ./use-case. We have patterns/pattern-shielding.md as a stub; this content would fit well there.
• Also, shielding is already on the strawmap.org roadmap, and the standardisation is happening at the protocol layer, not the app layer. Worth reflecting on in the framing.

I suggest reverting the approach and adding the native shielding to the current ./patterns/pattern-shielding.md, or creating a new pattern for native shielding.

[RogerPodacter]

Thanks for the review, @Meyanis95! A few thoughts:

I think this is an approach, not a pattern. Per the repo's taxonomy (approaches/README.md): "Patterns are reusable building blocks; approaches explain how to combine them for specific scenarios with detailed recommendations and trade-off analysis."

This doc combines four building blocks — an intent-transaction wallet authorization standard, a Privacy RPC server-side proving bridge, a system-contract enshrinement model, and a compliance layer (proof of innocence + issuer viewing keys) — into a phased strategy for achieving native private transfers on the L1.

pattern-shielding.md covers shielded ERC-20 transfers as a general technique (deposit, notes, ZK proofs, withdraw). This doc is specifically about how to enshrine that capability at the protocol level, which patterns to compose, and how to bridge adoption before wallet integration exists.

On the roadmap point — this is a proposal for protocol-layer standardization, not app-layer. The roadmap says "Private L1 / shielded transfers" but doesn't specify how. This is an approach to implementing that roadmap item.

Thanks!