The same cryptographic idea, a different chain, and no connection between the two projects whatsoever.
Stated plainly, because the name invites the question: TornadoSol is not affiliated with Tornado Cash, is not run by anyone connected to it, shares no code with it, and carries none of its history. The design idea — a fixed-denomination pool with zero-knowledge withdrawals — is public and has been implemented independently many times. That is what is shared. Nothing else is.
The shape of the mechanism. Fixed denominations so deposits are interchangeable. A commitment written to a Merkle tree. A zero-knowledge proof of membership instead of a receipt. A nullifier recorded so a note cannot be spent twice. A relayer so a fresh wallet does not have to be funded first. Any implementation of this idea will look like this, because the idea is the design.
| Ethereum pools | TornadoSol | |
|---|---|---|
| settlement | minutes, variable | seconds |
| cost per note | gas-dependent, historically dollars to tens of dollars | ~0.001 SOL, flat |
| proof verification | EVM precompiles | BN254 syscall, ~110k compute units |
| dominant cost | gas at the time you transact | permanent nullifier rent, paid once |
The flat, low cost is the practical difference. On Ethereum, mixing a small amount could cost more than the amount. Here the fee is the same ~0.001 SOL whichever pool you use, which makes small denominations viable and makes the choice of pool about anonymity rather than economics.
Not the pool. Not the anonymity set. Not the reputation, and not the legal history either. TornadoSol's pools started empty and their depth is whatever it is today — a fact printed on the pool picker rather than borrowed from somebody else's numbers. Anyone who tells you a new pool inherits an old one's crowd is selling something.