Stop trusting one person, one laptop, or one “black box” with your most sensitive powers.

This book helps you build a k-of-n cryptographic vault that cleanly separates what can remain public and straightforward from what needs to be protected and handled collectively:

Anyone can encrypt to the vault (public keys)
Anyone can verify signatures (public keys)
But only a quorum can sign or decrypt

You’ll get a reproducible workflow you can actually run: an offline Tails OS ceremony to generate and distribute shares, followed by practical procedures for encryption, verification, quorum-based signing, and quorum-based decryption.

Under the hood, you connect well-known primitives into one coherent system:

Shamir's Secret Sharing scheme (threshold control)
Ed25519 (signatures and public verification)
RSA-OAEP + AES-GCM (hybrid encryption with confidentiality and integrity)
Practical Python tooling aligned with the specification

Ideal for:

Secure release signing (no single maintainer can sign alone)
Legal/executive vaults and board-level approvals
Emergency access and recovery without a single point of failure
Any workflow where “one compromised actor” must not be enough

If you’re a cybersecurity practitioner, a computer science or math student, or a serious builder, this book gives you more than theory: it gives you a system you can run, verify, and defend.