Multi-Level Sequential Approval

Built for Institutional Security

The first blockchain account architecture that implements banking-grade defense in depth: isolated approval layers, amount-based thresholds, and time-locked progression.

How It Works - The Core Architecture

Sequential Approval Layers

Your account isn't a single multisig. It's a configurable chain of independent approval checkpoints.

Owner's Account

Your institutional account

Operations Layer

3 signers, need 2-of-3

+ 2 hours timelock

Compliance Layer

2 signers, need 2-of-2

+ 4 hours timelock

Executive Layer

1 signer, need 1-of-1

+ 24 hours timelock

EXECUTE

Click on any level to see details. Transaction must satisfy each level's quorum AND timelock before progressing.

Amount-Based Dynamic Configuration

Different Transactions, Different Security

The same account adapts its approval requirements based on transaction value.

Level 1: Operations

2-of-3
+ 1 hour

Level 2: Compliance

1-of-2
+ 2 hours
EXECUTE
2
Levels
3
Approvals Minimum
~3 hours
Total Time

Four Key Features That Enable Defense in Depth

Feature 1: Configurable Signers Per Level

Signers can be anyone: internal teams, external compliance providers, sub-custodians, auditors, or any combination. Each level operates independently for true isolation.

Internal Teams

Operations, Treasury, Executive

  • Alice (Operations)
  • Bob (Treasury)
  • Carol (Executive)

External Compliance

Chainalysis, Elliptic, TRM Labs

  • Chainalysis
  • Elliptic
  • TRM Labs

Sub-custodians

Banking partners

  • Bank A
  • Bank B

Auditors

Oversight committees

  • Audit Firm X
  • Oversight Board

Any Combination

Custom configurations

  • Mix and match as needed

Key benefit: Compromising operations staff doesn't give access to compliance credentials. Compromising Level 2 doesn't breach Level 3.

Feature 2: Time-Locked Progression

Why timelocks matter:

After Level 1 reaches quorum → Wait 2 hours → Level 2 can begin signing

This isn't a delay. It's a fraud detection window.

What happens during timelock:

  • • Automated monitoring systems scan for suspicious patterns
  • • Compliance teams review transaction context
  • • Any authorized party can still veto if fraud detected
  • • Internal controls have time to flag anomalies

"In 2023, the average time to detect account takeover was 14 hours. Time-locked progression gives your security systems breathing room."

Example timeline:

Hour 0Transaction Proposed

Level 1 begins review

Hour 2Level 1 Quorum Reached

2-hour timelock starts

Hour 4Level 2 Begins

Compliance review starts

Hour 8Level 2 Quorum Reached

4-hour timelock starts

Hour 12Level 3 Begins

Executive review starts

Hour 13Level 3 Approves

24-hour timelock starts

Hour 37Transaction Executes

Final execution

Total review window: 37 hours — Sufficient time for every independent party to investigate, verify, and respond.

Feature 3: Veto Power at Any Level

Negative signaling:

Any signer at any level can immediately cancel the transaction.

Standard multisig:

"We need 5 approvals to proceed"

Problem: Signers just wait to see if threshold is met

This system:

"Any of 9 people can deny"

Benefit: Every signer actively reviews, knowing they have veto power

How it works:

Level 1
0 / 2
Level 2
0 / 2

"If anyone at any level denies, the transaction stops immediately — no matter how many previous approvals."

Use cases for veto:

  • • Compliance provider flags sanctioned address
  • • Operations team spots unusual transaction pattern
  • • Executive notices unauthorized amount
  • • Monitoring system detects anomalous behavior

Feature 4: On-Chain Privacy

What the public blockchain sees:

0x742d35Cc6634C0532925a3b844Bc9e7595f0bEb → signed
0x9f4cB2c4E15e75e9f19e7E17f1B65f1E8e7C3F2A → signed
0x1a2B3c4D5e6F7a8B9c0D1E2F3a4B5c6D7E8F9a0B → signed

What your internal dashboard shows:

Alice Chen (Operations Manager) → signed
Chainalysis (Compliance Provider) → signed
David Park (CFO) → signed

Key benefit: Approver identities remain private on-chain. No public exposure of your organizational structure or approval hierarchy.

Attackers can't identify which addresses to target or social engineer based on public blockchain data.

Real-World Transaction Flow

Scenario: Treasury needs to move $500,000 USDC to a vendor

Transaction Proposed

Awaiting Level 1 approval

Hour 0

Amount: $500,000 USDC

Destination: 0x742d35Cc...

Proposed by: Operations Team

Required path: Level 1 → Level 2 → Level 3

Level 1 Review (Operations)

2-of-3 signers needed

Hour 1

Level 1 Timelock

2 hours remaining

Hour 3

Level 2 Review (Compliance)

2-of-2 signers needed

Hour 5

Level 2 Timelock

4 hours remaining

Hour 9

Level 3 Review (Executive)

1-of-1 signer needed

Hour 10

Final Timelock & Execution

Transaction executes

Hour 34

Why This Works - The Defense in Depth Guarantee

See how attacks fail against multi-level isolation, timelocked review windows, and veto power.

The Math of Defense in Depth

Standard 5-of-9 multisig:

  • • Breach 5 signers = 100% compromise
  • • All signers in one layer
  • • Single point of failure (just need 5)

This system (for $500k transaction):

  • • Must breach: 2-of-3 at Level 1 AND 2-of-2 at Level 2 AND 1-of-1 at Level 3
  • • Minimum signers to compromise: 5 independent parties
  • • BUT: They're across isolated systems, different organizations, different security models
  • • PLUS: Must evade 30+ hours of monitoring windows
  • • PLUS: Any single honest signer can veto

Probability comparison:

  • • Standard multisig: Breach 5 of 9 people
  • • This system: Breach 5 of 6 people ACROSS 3 isolated organizations AND evade 30 hours of monitoring

The difference is isolation, not just numbers.

Fully Configurable for Your Institution

Configure approval levels, signers, quorums, timelocks, and amount-based rules to match your institution's requirements. All configuration changes require existing multi-level approval for security.

Configure Approval Levels

Level 13 signers2h

Amount-Based Rules

Optional: Configure different approval flows for different transaction amounts

Your Configuration

Level 1

3 signers
2h
Signer 1Signer 2Signer 3
1levels
~2htotal time

Built on Battle-Tested Foundations

Core components based on Safe's proven patterns:

  • ✓ Signature verification logic
  • ✓ Owner management system
  • ✓ Transaction execution framework
  • ✓ Off-chain signature collection
  • ✓ Gas-optimized operations

Extended with institutional requirements:

  • ✓ Multi-level sequential progression
  • ✓ Amount-based runtime configuration
  • ✓ Time-locked checkpoints
  • ✓ Veto/deny capability
  • ✓ Privacy-preserving on-chain design

Comparison - Traditional vs. This System

FeatureStandard MultisigSafeThis System
Approval structureSingle layerSingle layer✓ Multi-level sequential
Amount-based rules❌ Fixed threshold❌ Fixed threshold✓ Dynamic per amount
Time-locked review❌ None⚠️ Optional delay✓ Per-level timelocks
Veto capability❌ Only via lack of approval❌ Only via lack of approval✓ Explicit deny at any level
Sequential progression❌ All parallel❌ All parallel✓ Must complete level N before N+1
Independent isolation❌ All signers equal❌ All signers equal✓ Each level independent
Configurable hierarchy❌ Flat structure⚠️ Via nested Safes✓ Native multi-level
Signer flexibility✓ Any address✓ Any address✓ Any address + role separation
On-chain privacy⚠️ Public addresses⚠️ Public addresses✓ Anonymous signers

Why Institutions Choose This

Asset Manager

$2B+ in tokenized securities under custody

Regulators require tiered approval, separation of duties, audit trails, and review windows. Standard multisig couldn't meet these requirements. This system provides:

  • • Tiered approval based on transaction size
  • • Independent compliance review (external providers)
  • • 24-hour review window for high-value transfers
  • • Complete audit trail on-chain

Digital Asset Bank

Multi-jurisdictional operations with external compliance

Operations team (internal), compliance providers (Chainalysis + Elliptic), and executives (different jurisdictions) need sequential review with isolation. This system enables:

  • • Sequential approval (not simultaneous)
  • • Isolation between operations, compliance, and executive layers
  • • Different approval rules for $5k vs $5M transactions
  • • Mapping to traditional banking workflows

Tokenization Platform

50+ real estate projects with varying requirements

Each project has different investor protection requirements, regulatory jurisdictions, and approval hierarchies. This system provides:

  • • Per-project configuration (one account per project)
  • • Custom approval flows matching project requirements
  • • Flexible timelocks for redemption windows
  • • Scalable to hundreds of projects

Frequently Asked Questions

Getting Started

1

Configuration Design

Work with our team to design your approval hierarchy: number of levels, signers per level, quorum requirements, timelocks, and amount-based thresholds.

1 week
2

Deployment & Verification

Smart contracts are deployed to your chosen network, verified on block explorers, and integrated with our management interface.

1 week
3

Signer Onboarding

Onboard signers, distribute keys, conduct training sessions, and run test transactions to ensure everyone understands the process.

1-2 weeks

Total timeline: 2-4 weeks from contract signing to production deployment. Complex configurations or regulatory requirements may extend this timeline.

Banking-Grade Security, Blockchain Speed

The Bottom Line

For the first time, institutions can use blockchain without compromising on security architecture.

What you get:

  • ✓ Defense in depth: Multiple isolated approval layers
  • ✓ Adaptability: Same account handles $1k and $10M with appropriate security
  • ✓ Real review windows: Time-locked progression catches fraud
  • ✓ Regulatory compliance: Separation of duties, audit trails, tiered authorization
  • ✓ Battle-tested foundations: Built on proven smart contract patterns

What you don't compromise:

  • ✓ Self-custody (no trusted third parties)
  • ✓ Blockchain settlement speed (execution is still instant once approved)
  • ✓ Transparency (full audit trail on-chain)
  • ✓ Composability (works with any DeFi protocol or tokenized asset)

This is how $10 trillion in traditional assets will move on-chain.