Security Architecture

Cypheron Core implements a comprehensive security architecture designed for post-quantum cryptographic applications requiring high assurance.

For complete security analysis, see the full Architecture Documentation.

Security Architecture Diagram

┌─────────────────────────────────────────────────────────────────────────────┐
│                         CYPHERON CORE SECURITY ARCHITECTURE                 │
│ ┌─────────────────────────────────────────────────────────────────────────┐ │
│ │                        APPLICATION LAYER                                │ │
│ │  • Memory Safety: Rust Compiler Guaranteed                             │ │
│ │  • Security Level: FULLY TRUSTED                                       │ │
│ └─────────────────────────────────────────────────────────────────────────┘ │
│ ┌─────────────────────────────────────────────────────────────────────────┐ │
│ │                        CYPHERON CORE API                               │ │
│ │  • Input Validation & Sanitization                                     │ │
│ │  • Secure Memory Management                                            │ │
│ │  • Error Handling & Recovery                                           │ │
│ │  • Security Level: CONDITIONALLY TRUSTED                              │ │
│ └─────────────────────────────────────────────────────────────────────────┘ │
│ ┌═════════════════════════════════════════════════════════════════════════┐ │
│ ║                        FFI SECURITY BOUNDARY                           ║ │
│ ║  • Buffer Bounds Validation                                            ║ │
│ ║  • Type Safety Enforcement                                             ║ │
│ ║  • Memory Ownership Control                                            ║ │
│ ║  • Security Level: CRITICAL TRUST BOUNDARY                            ║ │
│ └═════════════════════════════════════════════════════════════════════════┘ │
│ ┌─────────────────────────────────────────────────────────────────────────┐ │
│ │                        NIST C IMPLEMENTATIONS                          │ │
│ │  • Cryptographic Operations                                            │ │
│ │  • Manual Memory Management                                            │ │
│ │  • Platform-Specific Optimizations                                     │ │
│ │  • Security Level: UNTRUSTED (VERIFIED BY TESTING)                    │ │
│ └─────────────────────────────────────────────────────────────────────────┘ │
└─────────────────────────────────────────────────────────────────────────────┘

Trust Boundaries

Fully Trusted Zone

Rust Application Code & Core API

  • Type safety guaranteed by Rust compiler
  • Memory safety enforced automatically
  • Bounds checking on all array accesses

Conditionally Trusted Zone

Cypheron Core Unsafe Wrappers

  • Input validation and sanitization
  • Buffer allocation and lifetime management
  • Error handling and conversion
  • Manual safety verification required

Untrusted Zone

NIST C Reference Implementations

  • Manual memory management
  • Potential undefined behavior
  • Platform-specific behavior
  • Trust through verification and testing

Security Properties

Memory Safety

  • Rust Code: Automatic memory safety through type system
  • FFI Boundary: Manual validation with comprehensive testing
  • C Code: Trust through NIST reference implementation quality

Side-Channel Resistance

  • Constant-time implementations where feasible in C vendor code
  • Secure memory zeroization using Rust’s zeroize crate
  • Platform-specific secure random number generation

Supply Chain Security

  • SHA-256 verification of all vendor C code
  • Reproducible build process
  • Version-controlled checksum validation
  • Build failure on integrity violations

Attack Surface Analysis

Primary Attack Vectors

  1. FFI Boundary Exploitation: Buffer overflows, type confusion
  2. Memory Safety Violations: Use-after-free, double-free in unsafe code
  3. Supply Chain Attacks: Compromised vendor code, build system tampering
  4. Side-Channel Analysis: Timing attacks, power analysis

Mitigation Strategies

  1. Comprehensive Input Validation: All FFI inputs validated before C calls
  2. Bounded Buffer Operations: All C functions receive exact buffer sizes
  3. Integrity Verification: Cryptographic verification of vendor code
  4. Security Testing: Fuzzing, property-based testing, KAT validation

Vendor Code Provenance

All C implementations sourced from official NIST references:

  • ML-KEM: NIST FIPS 203 reference implementation
  • ML-DSA: NIST FIPS 204 reference implementation
  • Falcon: NIST PQC Round 3 submission
  • SPHINCS+: NIST PQC Round 3 submission

Each with SHA-256 integrity verification and controlled update process.

For complete technical details including FFI boundary analysis, memory safety model, and build process security, see the full Architecture Documentation.