Native Ethereum Time-Locking and Signature-Based Access Control Using Quantum-Resistant Keys and Zero-Knowledge Workflow Coordination
A quantum-resistant, zero-knowledge, multi-signature, on-chain, non-custodial Ethereum time-lock system enabling native access control through coordinated, resumable multi-party workflows.
Cold wallets, hot wallets, warnings to "never keep your crypto on exchanges," or that "if you don't have your keys, it's not your crypto"—these have been the mantras of cryptocurrency security since the beginning.
And they're good advice. But they've left a gap.
Truly decentralized, on-chain custody has served individuals with technical know-how well enough. But realistic financial situations that require time-locking, multi-party authorization, or other programmable parameters have forced individuals and organizations into an uncomfortable choice: rely heavily on third parties, or navigate complicated, disconnected decentralized tools that weren't designed to work together.
That's why David DeMayo and I built EthLock and recently filed the provisional patent.
EthLock is native Ethereum time-locking with signature-based access control using quantum-resistant keys and zero-knowledge workflow coordination. It's entirely on-chain with no third-party dependencies.
Here's what that means in practice: different people with different wallets, different schedules, and different levels of technical expertise can lock Ethereum assets, choose a time-lock duration, and specify who needs to sign before any funds move—all without relying on someone else's library, product, or company.
Tunable security written directly on the blockchain has significant implications for escrow arrangements, college funds, corporate treasury management, structured settlements, and any situation where multiple authorization signatures or timing conditions are involved.
What makes EthLock different from existing tools? Orchestrated, resumable workflows. Your keys stay in your pocket—and yours alone. The blockchain enforces the custody rules. A secure coordination layer keeps everyone aligned across time and distance without ever taking control of your assets.
Complemented by David's expertise in quantum-resistant cryptography and his already patent-pending equivalent system for Bitcoin, EthLock brings the power, immutability, and transparency of smart contracts to families, companies, institutions, and governments—without introducing counterparty risk.
This article goes deeper into how the system works, what makes it novel, and why coordinated custody matters for the future of on-chain finance.
We've filed a provisional patent for a new kind of Ethereum custody system—one that brings time-locking and multi-party authorization together under a single, coordinated on-chain workflow.
The idea is simple, even if the implications are not: instead of treating custody as a single transaction, we treat it as a coordinated process. Assets can be locked for a defined period of time, released only when the clock allows, and only when the right number of people have approved—while the system keeps track of progress so everything can pause and resume safely along the way.
This work was created by me and David DeMayo, CTO of Syntropy Software. David has also filed the provisional patent for the Bitcoin-side equivalent of this system, and together we developed the Ethereum-side architecture. While the two networks differ, the underlying goal is the same: we want to give individuals, teams, and organizations a way to express real-world custody rules—timing, shared control, and accountability—directly on-chain, without surrendering ownership to an intermediary.
Orchestrated Workflows and Non-Custodial Design
At the center of what we built is something we call orchestrated workflows. In practice, that means a custody operation—locking funds, waiting for a specified period, collecting approvals, and eventually releasing assets—is treated as a guided, trackable flow rather than a fragile chain of disconnected transactions. Ethereum enforces the rules inside smart-contract vaults, while a secure coordination layer makes sure the right steps happen in the right order and that the process can continue even if people log out, switch devices, or come back days or weeks later.
Most importantly, the system remains non-custodial. Every signature is made in the signer's own wallet. Every approval remains under the user's control. The coordination layer helps people work together across time and distance—but it never takes possession of the assets or the keys.
On-Chain Rule Enforcement
What makes our approach new and different starts with where the rules live.
Time-locks and multi-party approval don't rely upon external services, libraries or side layers. They are enforced directly by smart-contract vaults on Ethereum itself. When assets are locked, the blockchain—not a company, not a server, not a human—becomes the final authority on when and how they can move.
A vault can be configured with both a time condition (funds cannot be withdrawn before a specific moment) and a threshold of approvals (for example, two out of three authorized people must agree). These conditions are validated together on-chain, in the same execution context, before anything can happen. The result is a form of programmable custody that feels much closer to how people actually manage money in the real world, with timing, shared responsibility, and clear guardrails.
And all of this is user-defined. The person or organization creating the vault decides how long assets stay locked, who the authorized participants are, and how many approvals are required. The rules are explicit, transparent, and enforced by Ethereum itself.
Designed for Real-World Use
In the real world, custody decisions don't happen all at once. People are in different time zones. They use different wallets. They log in, log out, and come back later. Traditional blockchain tools weren't designed for that kind of reality.
This system is.
Each authorized signer uses their own Web3 wallet. No keys are pooled. No one has to move into a shared account. Approvals can happen over minutes, days, or weeks, and the system keeps track of what has already been done so the process can continue cleanly when the next person shows up.
If a signer approves and then closes their browser, nothing is lost. If a team, group, company or government pauses halfway through a multi-party approval process, it can be resumed later. If a long time-lock is involved, the workflow simply waits until the blockchain clock allows the next step.
Behind the scenes, a secure coordination layer tracks progress and sequences the steps, while the authoritative state—the vault, the lock, and the approval rules—lives on Ethereum. That combination is what makes the system both resilient and non-custodial at the same time.
Future-Proof Security Architecture
We also designed the architecture with the future in mind.
Cryptography / encryption and security are not standing still. As quantum computing and new attack models become part of the broader conversation, long-term custody systems need ways to evolve without forcing people into custodial platforms. For that reason, the system supports post-quantum-ready key handling and zero-knowledge-style safeguards that minimize the retention of sensitive material while preserving user control.
Even when advanced cryptographic options are enabled, authorization power stays with the users and enforcement stays on-chain. That makes this a foundation not just for today's security needs, but for long-horizon custody as well.
Practical Use Cases
When time-locking, multi-party authorization, and resumable workflows come together, a new class of on-chain use cases becomes practical:
- Estate planning with time-delayed inheritance: Assets can be programmed to unlock for beneficiaries at a future date, ensuring wishes are carried out.
- Corporate treasuries with dual authorization and delayed withdrawals: Company funds require multiple approvals and a mandatory waiting period, preventing rash decisions or fraud.
- Secured lending with time-based collateral release: Collateral is automatically returned after loan terms are fulfilled, without requiring manual intervention.
- Trustless escrow with automatic, rule-based settlement: Funds are held securely until predefined conditions are met, then released automatically.
- Structured payouts and settlements that follow transparent on-chain rules: Complex financial agreements can be codified and executed with perfect transparency.
These are everyday financial arrangements—now expressed directly in Ethereum smart contracts and coordinated through guided, resilient workflows.
Conclusion
We've filed a provisional patent for this system and are in the process of preparing the full filing. This is our first time sharing the work publicly, and we're excited to begin conversations with people who care about custody, security, and the future of on-chain coordination.
If you're building wallets, protocols, treasury systems, or institutional Web3 infrastructure—or if you simply hold crypto and think about how it should be managed over time—we'd love to compare notes.
About the Author
Mark Emery is a software developer specializing in full-stack Ethereum applications, smart contract architecture, and cryptographic custody solutions. Mark co-invented EthLock, a patent-pending quantum-resistant custody system, in collaboration with David DeMayo, CTO of Syntropy Software. His work focuses on building production-ready systems that solve real security problems in cryptocurrency custody while maintaining user control and non-custodial principles.
About the Co-Inventor
David DeMayo is the CTO of BitStream, leading the development of quantum-resistant crypto security solutions. With 30+ years in software development and 15 years specializing in cryptography and blockchain security, he is dedicated to protecting digital assets from emerging threats.