rememory

ReMemory

A digital safe with multiple keys, held by people you trust.

ReMemory protects your files and divides the key among people you choose. You decide how many must come together to open it. Each person gets a self-contained recovery tool that works offline, in any browser.*

* Time-locked archives need a brief internet connection at recovery time.

Recovery works without this project

Each person receives a bundle containing recover.html — a browser-based recovery tool. No servers. No dependencies. No need for this project to exist when recovery happens.

Download demo bundles to try the recovery process yourself.

…

Any 3 pieces can reconstruct the key, but a single piece reveals nothing — not "very little," mathematically zero information.

The number of people and the threshold are up to you: 2-of-3 for a small circle, 3-of-5 for a wider group, or 2-of-2 for a couple.

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Two Ways to Use ReMemory

Web UI (recommended)

Create bundles in your browser — no installation required.

Create Bundles	eljojo.github.io/rememory/maker.html
Documentation	eljojo.github.io/rememory/docs.html

Everything runs locally. Your files never leave your device.

CLI and Docker

For automation, scripting, or if you prefer the terminal.

# macOS (Homebrew)
brew install eljojo/rememory/rememory

# Linux (x86_64)
curl -Lo rememory https://github.com/eljojo/rememory/releases/latest/download/rememory-linux-amd64
chmod +x rememory
sudo mv rememory /usr/local/bin/

# Docker (self-hosted)
docker run -d \
  --name rememory \
  -p 8080:8080 \
  -v rememory-data:/data \
  ghcr.io/eljojo/rememory:latest

# Nix
nix run github:eljojo/rememory

See the CLI User Guide or the Self-Hosted Guide for complete documentation.

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Try It First

Before protecting real secrets, try the recovery process:

1. Download demo bundles (5 friends, any 3 can recover)
2. Open bundle-alice/recover.html in your browser
3. Alice's piece is pre-loaded — drag two more README files onto the page. Dragging an entire bundle works too.
4. When enough pieces are combined, the files unlock

This is the closest thing to what a real recovery feels like.

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What Friends Receive

Each friend gets a ZIP bundle containing:

File	Purpose
README.txt	Instructions, their unique piece, contact list
README.pdf	Same content, formatted for printing
MANIFEST.age	Your encrypted files (only included separately when over 10 MB)
recover.html	Recovery tool (~300 KB), runs in any browser. For smaller archives, everything is embedded — just open this file

A single piece reveals nothing. But tell your friends to keep their bundle somewhere safe — it's their responsibility to you.

More pages

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FAQ

Why ReMemory?

We all have digital secrets that matter: password manager recovery codes, cryptocurrency seeds, important documents, instructions for loved ones. What happens to these if you're suddenly unavailable?

Traditional approaches fail:

• Give one person everything → Single point of failure and trust
• Split files manually → Confusing, error-prone, no encryption
• Use a password manager's emergency access → Relies on company existing
• Write it in a will → Becomes public record, slow legal process

ReMemory takes a different approach:

• No single point of failure — requires multiple people to cooperate
• No trust in any one person — even your most trusted friend can't access secrets alone
• Offline and self-contained — recovery works without internet or servers*
• Designed for non-technical people — clear instructions, not cryptographic puzzles

Why I Built This

Two things drove me to create ReMemory.

First, I watched a documentary about Clive Wearing, a man who has lived with a 7-second memory since 1985. Seeing how fragile memory can be made me think about what would happen to my digital life if something similar happened to me.

Second, I've had several concussions from cycling accidents. Each time, I've been lucky to recover fully. But each time, I've been reminded that our brains are more fragile than we like to think.

ReMemory is my answer: a way to ensure the people I trust can access what matters, even if I can't help them.

Threat Model

ReMemory assumes:

• Your friends will only cooperate when needed
• At least threshold friends will keep their bundle safe
• Your device is trusted when you create bundles
• The browser used for recovery is not compromised

ReMemory does NOT rely on:

• Any server or cloud service
• Any ReMemory website or infrastructure
• Any long-term availability of this project
• The internet during recovery

See the Security Review for details.

Cryptographic Guarantees

Component	Algorithm
Encryption	age (scrypt passphrase mode)
Key derivation	scrypt (N=2²⁰, r=8, p=1)
Secret sharing	Shamir's Secret Sharing over GF(2⁸)
Integrity	SHA-256 checksums
Passphrase	256 bits from crypto/rand
Time lock (optional)	drand tlock (BLS12-381 IBE, inner layer)

A single piece reveals nothing about your secret. This is a mathematical guarantee of Shamir's Secret Sharing — any fewer than threshold pieces contain zero information about the original secret.

Time-Delayed Recovery (Experimental)

You can set a waiting period when creating bundles. Even with enough pieces, the files stay locked until the date you chose — for example, 30 days, 6 months, or a specific date.

This uses the League of Entropy (drand), a distributed randomness beacon run by organizations around the world. At recovery time, a brief internet connection is needed — not to send data, but to verify that enough time has passed.

CLI: rememory seal --timelock 30d (or 6m, 1y, 2027-06-15T00:00:00Z) Web: Enable under "Advanced options" in the bundle creator.

Important caveats:

• Recovery requires internet access (to check the drand beacon)
• If the League of Entropy stops operating before your time lock expires, recovery won't work
• Without the time lock, recovery works fully offline — the time lock adds this one dependency

Failure Scenarios

What if...	Result
A friend loses their bundle?	Fine, as long as threshold friends remain
A friend leaks their piece publicly?	Harmless without threshold-1 other pieces
ReMemory disappears in 10 years?	recover.html still works — it's self-contained
Browsers change dramatically?	Pure JavaScript with no external dependencies
You forget how this works?	Each bundle's README.txt explains everything
Some friends can't be reached?	That's why you set threshold below total friends
Time lock used, but no internet at recovery?	Wait and try again — data is safe, just needs the beacon check
League of Entropy shuts down?	Time-locked archives become unrecoverable — only a risk if you use the time lock feature

Development

# Using Nix (recommended)
nix develop

# Install dependencies
npm install

# Build
make build

# Run tests
make test         # Unit tests
make test-e2e     # Browser tests (requires: npm install)

# Preview website locally
make serve        # Serves at http://localhost:8000

Other Similar Tools

ReMemory isn't the first tool to use Shamir's Secret Sharing. Its focus is making recovery possible for non-technical people, without installing anything.

Shamir's Secret Sharing tools

Tool	Type	Input	Splitting Method	Output	Non-technical Recovery	Offline	Contact Details
eljojo/rememory	CLI + Web	Files & folders	Shamir's SSS	ZIP bundles with PDF instructions, recover.html, encrypted archive	Yes — open HTML in browser	Yes	Yes — included in each bundle
jesseduffield/horcrux	CLI	Files	Shamir's SSS	Encrypted file fragments	No — requires CLI	Yes	No
jefdaj/horcrux	CLI	Files (GPG)	Shamir's SSS (via ssss)	.key + .sig files, steganography in images/audio	No — requires CLI + GPG	Yes (TAILS recommended)	No
paritytech/banana_split	Web app	Text only	Shamir's SSS + NaCl	Printable QR codes	Partial — scan QR + type passphrase	Yes (self-contained HTML)	No
cyphar/paperback	CLI	Files	Shamir's SSS in GF(2^32)	Printable PDFs with QR codes + text fallback	Partial — scan QR or type text	Yes	No
simonfrey/s4 (site)	Web GUI + Go lib	Text/bytes	Shamir's SSS + AES	Text shares	No — copy/paste shares	Yes (save HTML locally)	No
xkortex/passcrux	CLI	Text/passphrases	Shamir's SSS	Text shares (hex/base32/base64)	No — requires CLI	Yes	No
ssss	CLI	Text (128 char max)	Shamir's SSS	Text shares	No — requires CLI	Yes	No
cedws/amnesia	CLI	Text/data streams	Shamir's SSS + argon2id	JSON file (Q&A-based, single user)	No — requires CLI	Yes	No
henrysdev/Haystack	CLI	Files	Shamir's SSS	Encrypted file fragments	No — requires CLI	Yes	No
antonio-ivanovski/shared-secret-encrypt (site)	Web app	Text only	Shamir's SSS + AES-GCM	Base58-encoded shares + encrypted message	Partial — web UI for decrypt	Yes (client-side, can save HTML)	No
MinorGlitch/ethernity	CLI (Python)	Files	Shamir's SSS + AES-256-GCM	Printable PDFs with QR codes + text fallback, bundled browser recovery kit	Partial — scan QR or type text	Yes	No

Other approaches

Tool	Type	Input	Method	Output	Non-technical Recovery	Offline	Contact Details
msolomon/keybearer (site)	Web app	Files	Layered encryption	Encrypted file download	Partial — web UI for decryption	Yes (client-side JS)	No
RobinWeitzel/secret_sharer (site)	Web app	Text only	Split-key AES-256 (fixed 2-of-2)	PDF with 2 QR codes + security code	Yes — scan QR codes	Yes (client-side)	No
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