14-Step Transaction Flow — 수탁형 지갑 DB 설계

14. 14-Step Transaction Flow

Stage 9 정식 명세 · 각 step 의 DB row 생성·갱신 매핑

transaction-lifecycle.md, p.4-5 + fireblocks-cloud-architecture.md 정합. 모든 service handoff 에 zero-trust 검증.

sequenceDiagram
  participant User
  participant API as Dev API Gateway
  participant Auth as Auth Engine (SGX)
  participant TM as Transaction Manager
  participant BS as Balance Service
  participant SS as Screening Service
  participant AML as AML Provider
  participant PE as Policy Engine (SGX)
  participant SV as Secure Vault (SGX)
  participant CSE as Co-Signer Engine (SGX)
  participant C1 as Co-Signer 1 (FB SGX)
  participant C2 as Co-Signer 2 (FB SGX)
  participant C3 as Co-Signer 3 (Customer)
  participant Node

  User->>API: 1. tx request
  API-->>API: 2. JWT 서명 access token
  API->>Auth: 3-4. JWT 검증 (cert store + Auth Engine)
  Auth-->>API: validated
  API->>TM: 5. tx
  TM->>BS: 5a. balance check
  BS->>Node: query
  TM->>SS: 5b/5c. AML + Travel Rule
  SS->>AML: query (Chainalysis / Elliptic / Notabene)
  TM->>PE: 6-7. policy evaluation (SGX)
  PE-->>PE: auto-approve OR collect approvals
  PE->>SV: 8. signing 개시
  SV->>CSE: 9. tx request cache (UUID + Policy rules)
  CSE->>C1: 10. signing ceremony
  CSE->>C2: 10. signing ceremony
  CSE->>C3: 10. signing ceremony
  C3->>CSE: partial sig
  Note over C3: optional Callback Handler attached
  CSE->>Auth: 11. partial signature hash 검증
  CSE->>SV: 12. signed tx 조립
  SV->>Node: 13. broadcast
  Node-->>Blockchain: 14. 최종 broadcast

Figure 6. 14-step transaction flow — Auth Engine / Policy Engine / Secure Vault / Co-Signer Engine 모두 SGX (Azure). Co-Signer 3 가 customer-side.

Step 별 DB row 매핑

Step	Action	DB row 생성/갱신
1	User → API tx request	`transactions` INSERT (status=SUBMITTED)
2-4	JWT 발급 + Auth Engine 검증	`auth_tokens` INSERT (access token, 6h)
5a	Balance Service → Node	(stateless query, no DB write)
5b	Screening Service → AML Provider	`aml_screening_results` INSERT (status=PENDING_AML_SCREENING)
5c	Screening Service → Travel Rule	`travel_rule_records` INSERT
6-7	Policy Engine 평가	`approval_requests` INSERT (status=PENDING_AUTHORIZATION), `approval_decisions` INSERT per approver
8	충분한 approvals → Secure Vault	`transactions.status` = QUEUED → PENDING_SIGNATURE
9	Vault tx request cache → Co-Signer Engine	`signing_requests` INSERT (UUID + policy_rule_ref)
10	Co-Signer 1/2/3 signing ceremony	`signing_events` INSERT per share (append-only)
10a	Co-Signer 3 → Callback Handler	`callback_invocations` INSERT (optional)
11	Auth Engine partial sig hash 검증	(SGX-internal, no DB write)
12	Secure Vault 서명된 tx 조립	`transactions.raw_payload_cbor` SET (set-once)
13	Node infrastructure broadcast	`broadcast_attempts` INSERT, `transactions.status` = BROADCASTING
14	Blockchain 최종 broadcast	`transactions.tx_hash` SET (set-once), status = CONFIRMING

Zero-Trust Handoff 의 DB 함의

각 service handoff 마다 derived cert 검증 — service-to-service 호출 자체가 audit event. service_handoff_events 테이블 (append-only) 에 from_service / to_service / cert_chain_hash / occurred_at 기록.