Legacy Vault

Inspiration

In today’s digital world, most of our assets — wallets, NFTs, social credentials — exist entirely on-chain. But what happens to them when we’re gone?

Legacy Vault was inspired by a deeply personal question:
“If something happens to me, how will my kids access my crypto?”

Existing solutions are either too centralized, too technical, or assume the user will be around forever. We wanted to build something timeless, trustless, and deeply human , a time-locked inheritance vault where secrets can be securely stored and only unlocked by heirs at the right time, with no third party involved.

What it does

Legacy Vault is a decentralized, time-locked vault system built on the TEN Protocol (TEE-secured). It allows:

Owners to store an encrypted secret (e.g. seed phrase, instructions, credentials)
Heirs to unlock it after a user-defined future timestamp using a unique unlock key and password
A fallback mechanism for the owner to unlock early via a private password
Vaults to be accessed without any backend , directly from the contract if needed

Each vault is created with a unique Vault ID that can be shared. Secrets are encrypted off-chain before submission. Only hashes and encrypted data are stored on-chain. No Backend

How we built it

Smart Contracts: Built in Solidity, deployed to TEN Protocol with TEE-backed privacy. The heirKeyHash, ownerKeyHash, and encryptedSecret are stored as private variables.
Frontend: Developed in React with Tailwind, shadcn/ui components, ethers.js, and Lucide icons. Fully responsive and heir-friendly.
Encryption Layer: Built a TypeScript-based utility to encrypt secrets client-side. Keys are never generated or stored in the frontend.
Development Process: Started with Bolt.new Project #1, transitioned to Cursor for contract development, then re-imported to Bolt.new Project #2 for finalization and testing.

Challenges we ran into

Designing for long-term digital inheritance without custodians or centralized storage
Ensuring user secrets never touched the backend, frontend storage, or logs
Supporting complete contract interaction even without a frontend (via Tenscan or CLI)

Accomplishments that we're proud of

Built a full-stack, privacy-respecting DApp from scratch within the hackathon window
Created an heir-friendly unlocking experience that avoids Web3 complexity
Achieved full contract-based vault functionality with no backend or third-party reliance

What we learned

Practical implementation of TEE-backed smart contracts with private state on TEN Protocol
Secure UX patterns for Web3 inheritance use cases
How to manage project lifecycle across tools like Bolt, Cursor, and GitHub