Private Transfers
Send and receive on Solana without publishing the amount, the recipient or the token. This is the part that runs today.
Deposit a token once and your balance lives as notes in a shielded pool. Moving it inside that pool publishes nothing an observer can use.
This is what the Sombra wallet does today, on devnet.
What a transfer hides
| Hidden | Public |
|---|---|
| The amount | That a shielded action happened |
| Which notes you spent | How many notes went in, and how many came out |
| Who you paid | The fee, in one fixed fee token |
| The token you moved | Your deposit, and any withdrawal |
Two rows deserve saying plainly. A deposit is public. It links your Solana wallet to your first note, and nothing inside the pool undoes that. A withdrawal is public on the way out. Everything between them is not.
No signature moves your money
A normal Solana transfer is authorised by a signature. A Sombra spend is authorised by a proof.
Your wallet proves, in zero knowledge, that it owns notes in the tree and that the outputs it creates add up to the inputs it spends. The program never sees an amount or an owner. It sees commitments, nullifiers and votes. Concepts has the mechanics.
That has a practical consequence. Because no signature of yours is needed to land the transaction, a relayer can submit it and pay the gas. Your Solana key never appears, and you do not need any SOL to spend.
Which parts are post-quantum
Worth being exact, because the phrase gets used loosely.
| Layer | What Sombra uses |
|---|---|
| Note encryption | ML-KEM-768 with AES-256-GCM (FIPS 203) |
| Spend authorisation | STARK proofs — no pairings, no trusted setup |
| Shielded keys | Hash-based. No elliptic curve owns or spends a note |
| Solana transaction signatures | Ed25519, like every transaction on Solana |
The last row is not ours to change, and it does not need to be. What matters is that nothing a quantum attacker could break later is protecting your privacy today. An archived Sombra ciphertext does not become readable in ten years. An Ed25519 signature on a relayer's public transaction says nothing about the shielded payment inside it.
Showing someone your history
Viewing keys come from a different branch of your phrase than spend keys, and Sombra issues one per week.
So "can you audit my account?" has a bounded answer. You hand over the weeks you mean — one tax year, one quarter — and every other week stays out of reach. A viewing key reads. It can never spend. Keys has the derivation.
Next: Private Swaps — using a shielded balance without leaving the pool.