SHAMIR'S SECRET SHARING // 2-OF-3 THRESHOLD

Crypto Inheritance
Without Trust

Split your seed phrase into three shards. Any two can recover it. Your beneficiary gets the third shard only when you stop responding.

ENCRYPTION
Client-Side Only
THRESHOLD
2-of-3 Shards
TRIGGER
90-Day Inactivity
TRUST
Zero Knowledge
// THE PROBLEM

$140B in Crypto Will Die With Its Owners

Self-custody solves the trust problem. But it creates a new one: when you die, your keys die with you.

4M+
Bitcoin lost forever
23%
Of holders have no inheritance plan
$0
Value of crypto without the key
OPTION 1: DO NOTHING

Your family gets nothing. Your crypto becomes permanently inaccessible. Wealth evaporates.

OPTION 2: SHARE YOUR SEED

Anyone with the seed can take everything. You're trusting them with 100% of your assets, 100% of the time.

OPTION 3: USE A CUSTODIAN

Banks, lawyers, exchanges. They can freeze, lose, or steal your assets. You've re-introduced trusted third parties.

Option 4: Shardium — Trustless inheritance through cryptography
// THE SOLUTION

The Shardium Solution

Split your seed phrase into 3 shards. Any 2 can recover it. No single party can steal it.

Shard A

Shard A

You keep this. Store in a safe or password manager.

Shard B

Shard B

Give to your beneficiary. Print it as PDF.

Shard C

Shard C

Held by Shardium. Released when switch triggers.

Any 2 shards = Full recovery
A + B =
A + C =
B + C =
A alone =
B alone =
C alone =
// PROTOCOL

How It Works

Mathematically secure. No single point of failure. No custodian risk.

01

Split Locally

Your seed phrase is split into 3 shards using Shamir's Secret Sharing. This happens entirely in your browser. We never see the original.

02

Distribute Shards

Shard A: You keep. Shard B: Give to beneficiary. Shard C: We store encrypted. Any 2 shards reconstruct the original.

03

Dead Man's Switch

We ping you every 30 days. After 90 days of silence, Shard C is automatically sent to your beneficiary.

// SECURITY MODEL

Zero Trust Architecture

Even if we're compromised, attackers get nothing useful.

ATTACK: Database Breach

We only store Shard C. Without Shard A or B, it's cryptographically useless. Information-theoretic security means it can't be brute-forced.

ATTACK: Rogue Employee

No one at Shardium can access your funds. The math prevents it. 2-of-3 threshold means we'd need to collude with your beneficiary.

ATTACK: Man-in-the-Middle

Splitting happens client-side, offline-capable. Your seed phrase never travels over the network. No interception possible.

ATTACK: Beneficiary Fraud

Shard B alone is useless. They need Shard C which only releases after 90 days of your inactivity. You control the heartbeat.

// OPEN SOURCE

Audit the Code

Everything is open source. Verify the cryptography yourself.

secrets.js-grempe
FastAPI
PostgreSQL
Vercel Edge
// EARLY ACCESS

Join the First Wave

Shardium is new. Early adopters get priority support and input on the roadmap.

Free
During early access
Open Source
MIT Licensed
Community
Built in public

Don't Let Your Crypto Die With You

Set up your vault in under 5 minutes. Your seed phrase never leaves your device.

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