The Genesis: From Static Schedules to Programmable Paths
Many cryptographic primitives, particularly those based on a Feistel-like structure, operate using a fixed "key schedule"—a hardcoded sequence of operations (e.g., three XOR and permutation steps). While effective, this represents a static, unchanging program.
Our research began with a core insight: to generalize this observation by asking a single, system-defining question:
"What if the cryptographic 'program' was not a static constant, but a dynamic, programmable input?"
This question led to our design of the Cryptographic Virtual Machine (CVM).
The PDE Model: A Cryptographic Virtual Machine (CVM)
The CVM is a conceptual machine we designed to execute cryptographic operations based on a defined sequence of instructions. It is characterized by three core components:
- A Path: A sequence of defined cryptographic
Rounds that acts as the program, dictating the order of operations. - Rounds: The individual cryptographic instructions (opcodes) that the CVM can execute. These include reversible permutations (e.g., stream cipher-like XORs, hash-based Feistel rounds) and irreversible state-manipulation functions (e.g., absorbing data into the CVM's state, writing the state to a buffer).
- A persistent internal State register: The CVM's memory. This 32-byte register evolves with each operation.
The statefulness is the critical innovation. Each round's cryptographic keys and parameters are derived from a combination of the master key and the CVM's current internal state. This ensures that every operation is cryptographically chained to the complete history of all prior operations within that session.
The Defining Trade-Off: The Explicit Path
The PDE model is a powerful paradigm that prioritizes absolute, explicit control. The Path is not a side effect; it is a first-class citizen in the protocol, granting the developer complete and verifiable authority over the exact sequence of cryptographic operations.
This explicit control, however, introduces a fundamental design trade-off. The Path becomes a piece of state that must itself be generated, stored, and securely distributed among all parties. It creates a tight coupling between the protocol logic and the cryptographic engine, which requires careful management.
This trade-off, in turn, drove our research toward a new question: "Could we preserve the stateful, history-dependent nature of the CVM, but make the path implicit and emergent, rather than explicit and pre-ordained?"
The Ariadne Answer: The Emergent Path
The Ariadne Protocol is the definitive answer to that question. It represents a different point in the design space. It preserves the stateful power of the CVM but makes the path implicit, woven into the data stream itself through the Labyrinth Construction. This design sacrifices explicit path control in exchange for zero-overhead path secrecy and greatly simplified state management.