What is SCypher?

• SCypher is a tool that enables deterministic encryption of BIP39 seed phrases.
• From one master seed and a password, SCypher generates a new, valid BIP39 phrase.
• The resulting phrase is reversible only with the correct password.

The Core Innovation

Enterprise-Grade Potential

• One master seed → thousands of operational wallets.
• No need to store derived phrases: regenerate them at any time using password.
• Perfect for:
  • Access compartmentalization.
  • Automated key generation for smart contracts.
  • Delegation of funds to departments or users.

Operational Delegation

• SCypher enables secure delegation of derived seed phrases to trusted personnel.
• Each derived seed is valid and usable on its own.
• Perfect for giving strategic employees the ability to sign transactions — without ever exposing the master seed.
• Each employee can be assigned a unique derived phrase using a password only known to the administrator.
• If needed, access can be revoked or rotated by generating a new derived phrase.

Security by Design

• Derived phrases do not reveal the master seed.
• Even if the password is guessed and the master is reached, it's indistinguishable from any other derived seed.
• Argon2id integration adds powerful brute-force resistance.
• When passwords are strong and diverse, reverse-engineering the system becomes computationally unfeasible.

Attack Scenarios and Real-World Protection

• If the master seed is never used directly, there is no external reference to identify it.
• Attacker who compromises one or more derived seeds:
  • Cannot confirm their relation.
  • Cannot verify a correct password guess.
  • Cannot recognize the master seed if reached.
• Strong KDF (Argon2id) makes brute force attempts extremely slow.
• Clear advantage for real-world systems needing hierarchical, segmented access.

Technical Foundations

• Fully implemented in Bash, no external dependencies.
• Optional Rust implementation for future hardened usage.
• Uses reversible XOR encryption seeded from password-derived entropy.
• Output passes checksum and entropy validation for BIP39 compliance.

Disclaimer and Research Frontiers

• SCypher is cryptographically sound based on current understanding and careful testing.
• Not yet formally audited.
• Anyone using SCypher in mission-critical systems should conduct independent review.
• Contributions welcome to strengthen, port, and test the system under diverse threat models.

Call to Action

• SCypher is free and open-source.
• Learn more:
  • Website: https://scypher.vercel.app
  • GitHub: https://github.com/moon-miner/bash-BIP39-seed-cypher
• Help build the future of deterministic encrypted seed management.
• Ideal for companies, institutions, and developers.