Bitcoin Inheritance Vault (Dead Man’s Switch)

Programmable Bitcoin UTXOs powered by Charms

Overview

Bitcoin Inheritance Vault is a trustless, non-custodial dead man’s switch for Bitcoin.

It allows a Bitcoin holder to lock BTC into a programmable UTXO that requires periodic heartbeats (proof of liveness). If the owner stops sending heartbeats, the funds are automatically released to a beneficiary — without multisig, lawyers, or custodians.

This is made possible by Charms, which adds programmable logic directly to Bitcoin UTXOs.

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Problem

Bitcoin has no native way to handle inheritance:

• ❌ No conditional ownership transfer
• ❌ No time-based logic inside UTXOs
• ❌ Multisig setups are complex and risky
• ❌ Custodial solutions break Bitcoin’s trust model

If keys are lost or the owner dies, funds are often lost forever.

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Solution

We use Charms Protocol to embed programmable logic directly into a Bitcoin UTXO:

• The owner must periodically prove they are alive (heartbeat)

• If the heartbeat expires:

  • Ownership automatically transfers
  • Funds can only be spent to a predefined beneficiary

All rules are enforced on Bitcoin, not off-chain.

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Core Concept: Heartbeat

A heartbeat is an owner-signed Bitcoin transaction that updates the vault’s state.

• It proves the owner still controls the private key
• It resets the inheritance timer
• It is fully on-chain and trustless

If no heartbeat is sent before the deadline, inheritance is triggered.

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How It Works (High Level)

1. Vault Creation

   • Owner locks BTC into a Charm-enabled UTXO

   • Sets:

     • Beneficiary address
     • Heartbeat interval (in blocks)

2. Heartbeat

   • Owner sends a signed transaction
   • Vault state updates with latest block height

3. Inheritance Trigger

   • If heartbeat expires:

     • Anyone can trigger release
     • Funds can only go to beneficiary

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Charm Logic (Simplified)

IF action == heartbeat
  AND signer == owner
  AND heartbeat not expired
→ update lastHeartbeatBlock

IF action == release
  AND heartbeat expired
→ send BTC to beneficiary

This logic is enforced by Bitcoin validation rules.

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Why Charms?

Without Charms, Bitcoin UTXOs:

• Cannot store state
• Cannot enforce time-based logic
• Cannot restrict spend destinations conditionally

Charms enables programmable Bitcoin by allowing:

• Stateful UTXOs
• Custom spend rules
• Block-height-based conditions

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Tech Stack

• Charms Protocol SDK
• TypeScript

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Security Properties

• Only the owner can send heartbeats
• Beneficiary cannot access funds early
• Owner cannot block inheritance after timeout
• No backend trust required
• No custodial risk

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Limitations (Current)

• Single beneficiary
• Manual heartbeat (no reminders)
• Testnet only

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Future Improvements

• Multiple beneficiaries
• Gradual release (vesting)
• Social recovery guardians
• Off-chain reminder service
• Legal document hash anchoring
• Mainnet deployment

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Why This Matters

Lost Bitcoin due to death or lost keys is estimated in the millions of BTC. This project demonstrates how programmable UTXOs can solve a real, emotional, and financially critical problem — without breaking Bitcoin’s trust model.