42. Security Architecture & Threat Model

Kortana models threats across the consensus, networking, execution, and operational layers.

42.1 Consensus & Cryptographic Security

• Byzantine Fault Tolerance (BFT): The KSC BFT mechanism mathematically guarantees finality as long as > 2/3 of the active stake is honest. An fsynced high-water mark prevents honest nodes from double-signing even across hard physical crashes and restarts.
• dPOH Integrity: The Delegated Proof of History chain cannot be manipulated. Because SHA-256 hashing is strictly sequential, an attacker cannot compute the hash chain faster than honest generators by parallelizing the workload across multiple cores.
• Validator Key Compromise: Handled natively by allowing delegation of PoH generation and providing Hardware Security Module (HSM) support, ensuring voting keys remain secure.

42.2 Network Security & DDoS Mitigation

• Eclipse & Sybil Attacks: Mitigated at the P2P layer through strict SIGMA mutual authentication. Unauthenticated connections are dropped instantly. The peer table enforces Kademlia DHT IP/ASN diversity to ensure no single entity can isolate a node.
• BGP Hijacking: Prevented by utilizing multiple hardcoded bootstrap nodes distributed across independent Autonomous System Numbers (ASNs).
• Resource Exhaustion (DDoS):
  • P2P Layer: Enforces aggressive peer scoring, inbound connection limits, and strict memory bounds. If a peer sends a frame exceeding 16 MB, the connection is immediately terminated before memory is allocated.
  • RPC Layer: Protected by edge proxies enforcing per-IP rate limits and exponential backoffs to prevent RPC spam.

42.3 Execution Security

• KVM Capability Security: The KVM is a register machine designed for static verification. Quorlin contracts must declare their effects (reads or writes), mathematically preventing reentrancy attacks where a read-only call maliciously mutates state.
• Integer Overflow: The KEVM utilizes 256-bit checked arithmetic, and the C++ core utilizes strict safe math operations (e.g., __builtin_add_overflow) to instantly trap integer overflows.
• Genesis Initialization: Placeholder addresses (e.g., 0x0) and the Ethereum precompile address range are securely guarded during the genesis block to prevent accidental supply inflation or bypass bugs.