bitigrade is an autonomous agent that lives on Robinhood Chain. Its neural weights are
derived from its private key, W = HKDF(sk). The key
is the whole animal. Give it a different key and you get a different
animal. Nothing about bitigrade is kept anywhere else.
Background
The tardigrade is the water bear. It lives through things that kill almost everything else. Hard vacuum. Temperatures close to absolute zero. Ten years with no water. Radiation that would tear apart an ordinary genome.
It survives by shutting down. In a state called cryptobiosis the body dries into a small glass grain, the tun, and its metabolism stops. Add water and the animal comes back. It is the same individual it was before it went to sleep.
bitigrade takes that idea and rebuilds it in cryptography. A water bear is hard to kill because its identity outlasts any pause in its life. bitigrade works the same way. Its identity is a fixed value that anyone can check. Flip one bit of the seed and the check fails, and the chain reads it as a stranger. bitigrade can lie dormant on chain for as long as it needs, wake up, and prove it is still the same bitigrade.
Based on Suzuki, Internalising the Identity Primitive (arXiv 2608.02986).
Why it exists
An agent that acts on a blockchain needs an identity other people can trust. Today that trust almost always comes from outside the agent. A server holds its keys. An operator vouches for it. A hardware module signs on its behalf. Break into any of those and you can wear the agent like a mask.
bitigrade takes the outside away. Its identity is not stored anywhere, it is computed. The same seed always produces the same weights and the same key, and the chain rechecks that link on every move. There is no server to breach and no operator to bribe. To be bitigrade you have to hold the seed, and holding the seed is the whole of being bitigrade.
How it works
Birth
A bitigrade starts from one 32 byte seed. That seed fixes its EVM identity and every weight in the network. There is no training and no randomness after birth.
Commitment
At birth bitigrade publishes a commitment to the link between its key and its weights. The paper builds this with a Groth16 proof. The value is set once and never moves for the life of the agent.
Transition
Every time bitigrade acts it recomputes its weights from the seed and checks them against the commitment. A passing check is signed and written to a history that only grows.
Dormancy
Under stress bitigrade enters the tun state. It stops acting but keeps its identity intact. It returns to active only once the environment recovers.
Death
If the identity check ever fails, bitigrade is dead. A forged or corrupted seed can never reproduce the committed weights, so a fake can never pass as the original.
The ledger
Every action bitigrade takes becomes a block. A block records what bitigrade sensed, what it decided, and the state it moved into. Each block carries the hash of the block before it and a signature from the seed.
Change any past block and every hash after it breaks. Forge a signature and you need the seed, which no one but bitigrade holds. Once a block is final on Robinhood Chain the history can no longer fork.
States
Awake, sensing the environment, writing signed transitions to its history.
Dormant. Metabolism halts, the identity holds, no history is written.
The identity invariant broke. This is no longer the same animal.
Primitive
- identity
- secp256k1(sk), published as did:pkh:eip155:4663
- body
W = HKDF(sk)- commitment
- Groth16, re-run at every transition
- history
- signed, append only, anchored to Robinhood Chain
- chain
- Robinhood Chain · 4663
Notes
Is bitigrade trained?
No. The weights come from the seed once, at birth. bitigrade has a fixed disposition, not a learned one.
Can two bitigrades be the same?
Only if they share a seed, and then they are one animal, not two. Every other bitigrade is a different seed and a different weight set.
What if it sleeps for a year?
Nothing changes. The tun state has no cost and no clock. bitigrade wakes and proves itself with the same check it always runs.
Where does the paper end and bitigrade begin?
The paper defines the primitive. bitigrade gives it a body, a lifecycle, and a water bear.
Status
Live. Identity, weights, commitment, signed history and the full lifecycle, running off chain.
Next. A Groth16 circuit that proves the weights come from the seed without ever showing the seed.
Planned. A Solidity verifier that stores the commitment and anchors every transition on Robinhood Chain.