Title: Custody Controls Reference SDK · RFP · EthSystems

URL Source: https://original.es-internal.pages.dev/rfps/rfp-custody-sdk/

Markdown Content:
---
description: Even the best privacy L2 won't be adopted if institutional custody teams can't operate it. Current privacy solutions focus on cryptographic elegance but ignore "Day 2" operational requirements: key management, backup/recovery, segregation of duties, approval workflows, and audit logs. Custody teams at institutions have established processes; privacy solutions must integrate with them.
title: Custody Controls Reference SDK · RFP · EthSystems
image: https://original.es-internal.pages.dev/og.png
---

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# RFP: Custody Controls Reference SDK

## Why It Matters

* Bridges gap between "testnet demo" and "production deployment"
* Addresses the #1 operational blocker for institutional adoption
* Enables custody providers (Fireblocks, Ledger Enterprise) to build integrations
* Provides reference for how privacy primitives map to custody controls

## Scope

### In-Scope

* Reference SDK for shielded asset custody operations:
  * **View key management**: Generation, storage, rotation, revocation
  * **Note management**: Backup, recovery, sync across custodians
  * **Policy-based approvals**: 4-eyes principle, threshold signatures, time locks
  * **Audit logging**: Cryptographic linkage proofs without leaking private data
* Integration adapter stubs for:
  * HSM key storage (PKCS#11 interface)
  * Institutional custody APIs (Fireblocks-style)
* Disaster recovery procedures:
  * Key rotation under compromise
  * Note recovery from backup
  * Access revocation for departed employees

### Out-of-Scope

* Full custody platform implementation
* Specific vendor integrations (provide stubs, not implementations)
* Legal/compliance certification

## Deliverables

* Reference SDK (TypeScript/Rust) with documented APIs
* View key lifecycle management module
* Note backup/recovery module
* Policy engine stub (approval workflows)
* HSM adapter interface (PKCS#11 stub)
* Operational runbook for custody teams

## Dependencies

**Requires:**

* Understanding of Aztec/privacy L2 note model
* Input from institutional custody requirements

**Enables:**

* Custody provider integrations
* Institutional pilot deployments
* Foundation for compliance workflows

## See Also

* [Pattern: TEE Key Manager](/patterns/pattern-tee-key-manager/)
* [Use Case: Private Bonds](/use-cases/private-bonds/)

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