The Ariadne Protocol is our exploration of a different cryptographic model. The work began with an observation of primitives like the Lion transform, which use a static, hardcoded sequence of operations. This led us to ask: What if the cryptographic "program" wasn't a constant, but a dynamic, history-dependent variable?
Our first step was a "Cryptographic Virtual Machine" that took an explicit list of operations (a "Path"). This worked, but required sharing the Path object—an explicit dependency that needed to be managed.
The Ariadne Protocol is the maturation of that idea. It eliminates the explicit Path by making it implicit and emergent.
The core design is:
The Labyrinth: A large, deterministically-generated binary tree of cryptographic rounds.
The Thread: The secret path taken through the Labyrinth. This path is not stored or transmitted. It's rediscovered for each block of data by computing a keyed hash of the CVM's secret state and the public ciphertext chunk: hash(key, state, chunk).
This makes the cipher aperiodic: because the state ratchets forward after every block, the sequence of operations is guaranteed to never repeat. It also creates inherent tamper evidence—any modification to the ciphertext "snaps the thread" and turns subsequent output into noise.
This is experimental, unaudited alpha software. We are publishing it under CC0 because we believe foundational work like this should be an unrestricted public good.
E.g. the program goes through a state that is effectively 2DES which enables a meet-in-the-middle attack which allows an attacker to jump into the path at that point and dramatically reduce the search space for the next or preceding block etc?
The key and IV for every single round are derived from a keyed hash of the CVM's current state. This state is a cryptographic digest of the entire operational history up to that point.
So, even if a path structurally resembled a weak cipher like 2DES, the rounds would not have related keys. Each step is effectively a fresh cipher instance with a unique, unpredictable key. A meet-in-the-middle attack is not possible because there is no "middle" with a key relationship to exploit.