Faq

Cryptosign Custom Citadel Plates – Shamir SSS + Blind Printing

The most secure and versatile physical backup solution for Bitcoin, Ethereum, and high-value digital assets.

Cryptosign Custom Citadel Plates combine military-grade durability with mathematically proven Shamir’s Secret Sharing (SSS) and our proprietary Blind Printing technology. Your seed phrase or private keys are split into encrypted shares locally on your air-gapped machine. We never see your plaintext data at any point.

Material Tactical Specifications

Material Heat Resistance Impact & Water Weight Production Best For
Aerospace Titanium 1,668°C Excellent / Immune 18–22 g 5–7 days Long-term HODLers, family offices, institutions
Cold-Rolled Stainless 1,400°C Very Good / Immune 25–30 g 4–6 days Serious individual users & secure vault storage
Carbon Fiber (Infill) 800°C+ Excellent / Immune 8–12 g 2–4 days Modern stealth look + lightweight strength
Tactical Polymer 300°C+ High / Immune 10–14 g 1–3 days Everyday deployment, high-durability balance

All plates feature CNC or High-Precision Laser ablation. Thickness ranges from 1.0mm (Stainless) to 2.2mm (Carbon/Polymer).

In-Depth Armor Guide

  • Aerospace Titanium: The ultimate premium material. Highest melting point, superior corrosion resistance, and unmatched longevity. Ideal for "set-and-forget" multi-generational protection.
  • Cold-Rolled Stainless: Proven, robust all-rounder with extreme heat and impact resistance at a more accessible tier.
  • Carbon Fiber Composite: High-performance 3D-printed composite with an exceptional strength-to-weight ratio. Modern matte finish, extremely light yet incredibly resilient.
  • Tactical Polymer: Engineering-grade synthetic armor offering exceptional UV, water, and heat resistance for rapid deployment.

How It Works – The Air-Gapped Protocol

  1. Launch the strictly air-gapped Cryptosign SSS Terminal to split your seed phrase.
  2. Encrypt your shares locally on your own offline device.
  3. Procure your blank plates via our secure checkout.
  4. The Drop: Transmit your encrypted metadata to our engineering team via our end-to-end encrypted Signal Messenger channel.
  5. Receive your blind-printed plates in sterile packaging, verify reconstruction, and distribute to your secure locations.

Technical Specifications

  • Compatibility: All BIP39 hardware wallets (Ledger, Trezor, Coldcard, etc.)
  • Payload Formats: QR codes, Hexadecimal, Binary dots, Alphanumeric string
  • Dimensions: Standard credit card profile (85.6 × 53.98 mm)
  • Manufacturing: ISO-standard CNC, Laser Ablation, and Industrial FDM
  • Security Features: Tamper-evident holographic seals, unbranded sterile shipping.

Cryptographic Architecture & Security Protocols The Cryptosign SSS Terminal utilizes state-of-the-art cryptographic primitives to ensure your payload is as digitally impenetrable as the physical plates it is printed on. All computations occur strictly client-side on your local machine.

  • Key Derivation (Argon2id): We utilize Argon2id—the winner of the Password Hashing Competition—to stretch any user-applied passwords or PINs. This memory-hard algorithm provides maximum resistance against GPU, FPGA, and ASIC brute-force attacks.
  • Authenticated Encryption (AES-256-GCM): Prior to threshold splitting, your seed phrase is heavily encrypted using AES-256-GCM. This ensures both absolute confidentiality and ciphertext integrity. We blind-print the ciphertext, never the plaintext.
  • Entropy Generation (CSPRNG): All polynomial coefficients required for the Shamir’s Secret Sharing split are generated locally utilizing a Cryptographically Secure Pseudo-Random Number Generator (CSPRNG), ensuring zero algorithmic predictability.
  • Mathematical Thresholds (SSS): The encrypted payload is divided using standard Shamir’s Secret Sharing over a Galois Field. A single share contains zero usable data; it is mathematically impossible to reconstruct the payload without assembling the exact physical threshold you configure (e.g., 3-of-5).

Frequently Asked Questions

  • What is Blind Printing?

You encrypt locally with our offline SSS Tool. We only manufacture the encrypted cipher-data. We cannot read, decipher, or access your actual seed phrase.

  • Can I mix materials in one threshold set?

Yes. For a 3-of-5 threshold, many clients deploy Titanium shares to bank vaults, and Tactical Polymer shares to secondary locations.

  • How often should I test reconstruction?

Annually, or after any major geographical relocation. The free offline terminal makes secure auditing immediate.

  • Do you offer volume or institutional orders?

Yes. For bespoke corporate hardware and volume pricing, contact our secure channel: secure@cryptosign.ai

What is your warranty policy?

  • 30-day money-back guarantee on blank hardware + 2-year physical manufacturing warranty.

Made in Belgium • Agoria Member • Zero-Knowledge by Design