Quantum computers will break today's cryptography. Silica is ready.
The Quantum Threat
Current blockchain cryptography relies on mathematical problems that quantum computers can solve efficiently:
- ECDSA signatures: Shor's algorithm breaks elliptic curve cryptography
- RSA: Also vulnerable to Shor's algorithm
- Timeline: Cryptographically-relevant quantum computers expected within 10-15 years
Chains designed today need to be secure tomorrow. Silica builds in quantum resistance from day one.
Post-Quantum Cryptography
Silica uses NIST-approved post-quantum algorithms:
Signature Scheme: ML-DSA (Dilithium)
// Primary signature algorithm
use pqcrypto_dilithium::dilithium3;
fn sign_transaction(tx: &Transaction, sk: &SecretKey) -> Signature {
dilithium3::sign(tx.hash(), sk)
}Lattice-based signatures secure against both classical and quantum attacks.
Dual Key Architecture
Silica uses two key types for different purposes:
| Key Type | Algorithm | Purpose | Rotation |
|---|---|---|---|
| Identity Key | Dilithium (PQ) | Long-term identity, governance | Rare |
| Epoch Key | EC-VRF | Validator selection | Every 5-10 min |
Epoch keys use classical EC for performance in VRF operations, but rotate so frequently that even future quantum computers couldn't break them in time.
Byzantine Fault Tolerance
Beyond cryptography, Silica's consensus provides strong security guarantees:
- Safety: Never commits conflicting transactions, even with 1/3 malicious validators
- Liveness: Continues making progress with 2/3+ honest validators
- Accountability: Misbehaving validators can be identified and slashed
Slashing Conditions
- Double signing: Signing conflicting blocks in the same round
- Equivocation: Sending different messages to different validators
- Unavailability: Extended downtime (for operators, not passive holders)
Multi-Factor Validator Selection
Validator selection considers multiple factors to prevent gaming:
Weight Formula
w_i = (1 + stake_i)^0.5 × (rep_i)^1.0 × (geo_i)^1.2- Stake: Diminishing returns (square root) prevent plutocracy
- Reputation: Linear weight rewards consistent performance
- Geography: Slight boost for diversity prevents clustering
Defense in Depth
Security isn't just one layer—it's multiple overlapping protections:
Cryptographic
Post-quantum signatures, hash-based commitments
Economic
Slashing, stake requirements, reputation systems
Architectural
Separation of concerns, validator rotation, geographic distribution
Future-Proof Upgrades
Silica is designed for cryptographic agility:
- Algorithm versioning: Signatures include algorithm identifiers
- Smooth migration: Dual-signing during transition periods
- Governance control: Algorithm updates via on-chain governance
Security You Can Trust
Silica is designed for the long haul—secure against today's threats and tomorrow's quantum computers.
Post-quantum ready. Byzantine resilient. Built for centuries.